JP4684372B1 - Manufacturing method of semiconductor light emitting device substrate - Google Patents

Abstract

A method of manufacturing a high-performance semiconductor light-emitting element substrate while shortening the manufacturing time is provided.
A substrate heating step S3 for heating the substrate, a substrate cleaning step S6 for cleaning the substrate S, a dielectric layer forming step S7 for depositing dielectric layers H and L on the substrate S, and heating the substrate The substrate heating stop step S8 for stopping the substrate, the cooling step S9 for absorbing the radiant heat by the cooling means 11, 12, 13 to cool the substrate S and the substrate holding means 3, and the reflective layer R on the dielectric layers H, L And a reflective layer forming step S11 for vapor-depositing the semiconductor light-emitting element substrate.
[Selection] Figure 4

Description

  The present invention relates to a method for manufacturing a semiconductor light emitting element substrate, and more particularly, to a method for manufacturing a high performance semiconductor light emitting element substrate with reduced manufacturing time.

  Semiconductor light-emitting elements (LEDs) are low in power consumption, have a long lifetime, and have high luminous efficiency, and thus are being put to practical use as light sources. In the field of semiconductor light emitting devices, GaN-based compound semiconductors such as GaN, GaAlN, and InGaN have been widely used for visible light emitting devices, high-temperature operating electronic devices, and the like.

  In the manufacture of a GaN-based compound semiconductor, a sapphire substrate is generally used as a crystal substrate in order to grow a semiconductor film on the substrate surface. Since the sapphire substrate is insulative, an electrode cannot be provided on the surface on the back side of the sapphire substrate with respect to the substrate surface on which the light emitting layer made of a GaN-based compound is provided. An electrode is provided.

  More specifically, a buffer layer, an n-type GaN-based compound layer, a GaN-based light emitting layer, and a p-type GaN-based compound layer are sequentially stacked on a sapphire substrate, and a p-electrode is provided thereon. In general, an n-type electrode is provided by partially exposing an n-type GaN-based compound layer by etching.

  Therefore, an n-type GaN-based compound layer, a GaN-based light-emitting layer, and a p-type GaN-based compound layer are sequentially stacked on a sapphire substrate, and a p-electrode and an n-electrode are provided on the same surface as these layers, so that semiconductor light emission An element is formed.

  When mounting the semiconductor light emitting element having the above configuration on various devices, the mounting methods are roughly classified into two types, face-up mounting and face-down mounting. Face-up mounting is a method of arranging a substrate on the device side with the surface on which the electrode is formed facing upward, and is a configuration for extracting light from the electrode side. On the other hand, face-down mounting is a method in which an electrode is disposed on the device side with the surface on which the electrode is formed facing downward, and is a configuration in which light is extracted from the substrate side.

  In the case of face-up mounting, in the semiconductor light emitting device, the light extraction efficiency can be improved by forming the reflective layer on the surface opposite to the surface on which the layers and electrodes are formed on the sapphire substrate. As a material used for the reflective layer, aluminum (Al), silver (Ag), or the like having a high reflectance in the emission wavelength range (about 450 to 470 nm) of the blue LED is used. It is known that the reflection efficiency in the emission wavelength range of the blue LED is about 92% for Al and about 95% for Ag.

  A higher reflectance can be obtained by providing a plurality of dielectric layers serving as a reflection enhancement layer between the sapphire substrate and the reflective layer made of the metal. This dielectric layer is composed of a dielectric layer (H) made of a material having a high refractive index and a dielectric layer (L) made of a material having a low refractive index, each having an optical film of (λ) / 4 with respect to a wavelength of 460 nm. It is formed by alternately laminating so as to be thick.

The structure of the semiconductor light emitting element substrate including the dielectric layers having different refractive indexes is simply expressed as the following Expression 1 or Expression 2.
Sapphire substrate / aL (HL) ^b / Al (or Ag) (Formula 1)
Sapphire substrate / cH (LH) ^d L / Al (or Ag) (Formula 2)
At this time, a, b, c, and d are integers.
In the semiconductor light emitting device substrate having the configuration represented by the above formula 1 or 2, the material of the high refractive index dielectric layer (H) is a low refractive index such as TiO ₂ , Ta ₂ O ₅ , Nb ₂ O ₅ or the like. As the material of the dielectric constant layer (L), SiO ₂ or the like is used.

When TiO ₂ is used as the material for the high refractive index dielectric layer (H) and SiO ₂ is used as the material for the low refractive index dielectric layer (L), the calculation results of the optical characteristics are as shown in FIG. As shown in FIG. 7, the high refractive index dielectric layer (H) and the low refractive index dielectric layer (L) are preferable because the higher the b and d, the higher the reflectance. However, if b and d are large, the process time becomes long, and the heat conduction deteriorates against the heat generation of the light emitting layer, so 2 <b <4 is suitable.

  When the dielectric layer is formed on the sapphire substrate, a vacuum deposition method is generally used. In the vacuum evaporation method, when the dielectric material is evaporated toward the substrate surface in the vacuum chamber, the evaporation method is performed by irradiating ions to the evaporation layer deposited on the substrate, that is, ion assist. Vapor deposition methods are known.

  In this vapor deposition method, a relatively low energy ion beam (gas ions) is irradiated to the substrate by an ion source, and electrons are irradiated to the substrate by a neutralizer called a neutralizer. With this configuration, it is possible to produce a dense optical thin film by using the kinetic energy of the ion beam while neutralizing the charge accumulated on the substrate by the ion beam (for example, Patent Document 1). In addition, crystallization of the formed dielectric layer can be prevented, and a thin film having excellent optical characteristics and excellent environmental resistance characteristics can be formed.

  However, in the technique described in Patent Document 1, the evaporation source becomes a high temperature of about 2000 ° C. when the dielectric layer is formed. Further, when an ion source for irradiating an ion beam is used, the ion source itself becomes high temperature, and the substrate is heated along with the ion irradiation. The substrate temperature at this time depends on the material of the dielectric layer, the thickness of the deposited film, the number of layers, and the like, but the substrate temperature is heated to about 100 ° C. or higher.

  As a result, the substrate is heated by radiant heat using an evaporation source or an ion source as a heat source, and the substrate temperature is high after the dielectric layer is formed. However, when a reflective layer made of Al, Ag, or the like is formed on the dielectric layer, it is necessary to form the film by cooling the substrate temperature to 50 ° C. or lower in order to obtain good optical characteristics. Therefore, in manufacturing a semiconductor light emitting device substrate, in order to form a plurality of dielectric layers and a reflective layer such as Al on the back surface of the sapphire substrate, it is necessary to provide a cooling time for cooling the substrate. There was a problem that it took a long time.

  As a technique for preventing such an increase in the substrate temperature, Patent Document 2 proposes a technique for providing a cooling surface in the vacuum chamber for cooling the substrate. According to this technique, since the substrate is cooled by the cooling surface provided on the side opposite to the evaporation source with respect to the substrate, an increase in the substrate temperature can be prevented.

JP 2007-248828 A JP 2008-184628 A

However, the technique disclosed in Patent Document 2 is a technique for forming a film by a vacuum deposition method on a substrate made of a material having a low thermal deformation temperature such as plastic, and a technique for manufacturing a semiconductor optical element. More specifically, it does not describe a technique for forming a high-performance reflective layer.
Therefore, there has been a demand for a method for manufacturing a high-performance semiconductor light-emitting element substrate using the technique disclosed in Patent Document 2 with a high reflectance of the reflective layer.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a semiconductor light emitting device substrate with high performance while shortening the manufacturing time.
Another object of the present invention is to provide a method for manufacturing a semiconductor light-emitting element substrate that reduces the manufacturing cost of the semiconductor light-emitting element substrate and is low in manufacturing cost.

According to the method for manufacturing a semiconductor light-emitting element substrate of the present invention, the above-described problem is that a layer made of any one of titanium oxide, zirconium oxide, tantalum oxide, and niobium oxide, an aluminum oxide, A semiconductor light-emitting element substrate comprising a dielectric layer formed by alternately combining layers made of silicon oxide or magnesium fluoride, and a reflective layer made of aluminum in order on one surface. A manufacturing method comprising: a substrate holding step for holding the substrate on a substrate holding means disposed in a vacuum chamber; a vacuum evacuation step for evacuating the vacuum chamber; and the vacuum evacuation step. a substrate heating step of heating the substrate, and the substrate cleaning step of cleaning a substrate by radiating an ion to the substrate, the temperature of the substrate and 100 to 120 ° C., before Arranged a dielectric layer forming step of depositing a pre Symbol dielectric layer on a substrate, and the substrate heating stop step of stopping the heating of the substrate, the non-contact with a position and the substrate in the vicinity of the substrate A cooling step of absorbing radiant heat from the substrate and the substrate holding means to start cooling the substrate and the substrate holding means, and a temperature of the substrate of 25 to 70 ° C. And a reflective layer forming step of depositing the reflective layer on the layer in this order.

In the conventional method, since the substrate is disposed in a vacuum, it is insulated from the vacuum, and as a result, it takes a long time to cool the substrate. Further, in the dielectric layer forming step, the evaporation source and the ion source are heated, and the substrate receives the radiant heat, so that the cooling efficiency is very low.
With respect to such a problem, according to the method for manufacturing a semiconductor light emitting device substrate of the present invention, it is possible to effectively cool the substrate by absorbing the radiant heat from the substrate by the cooling means. Therefore, even if the substrate temperature rises after forming a plurality of dielectric layers, the cooling time for absorbing the radiant heat of the substrate in the vacuum chamber is provided, so that the substrate cooling time can be shortened. Manufacturing time can be shortened.
Moreover, a high reflectance can be obtained by using aluminum with a high reflectance as the material of the reflective layer. And it can be set as the reflection layer provided with high adhesiveness with respect to each dielectric material layer.
Furthermore, by using a high-refractive index dielectric and a low-refractive index dielectric as the dielectric layer material and alternately depositing them, a higher reflectivity can be obtained when combined with the reflective layer. .

In addition, according to the method for manufacturing a semiconductor light emitting device substrate of the present invention, the above-described problem is that a layer made of any of titanium oxide, zirconium oxide, tantalum oxide, and niobium oxide is formed on the substrate , and aluminum. Semiconductor light emitting device comprising a dielectric layer formed by alternately combining layers made of oxide, silicon oxide, or magnesium fluoride, and a reflective layer made of aluminum in order on one surface An element substrate manufacturing method comprising: a substrate holding step for holding a substrate on a substrate holding means disposed in a vacuum chamber; a vacuum evacuation step for evacuating the vacuum chamber; and substantially simultaneously with the vacuum evacuation step. The substrate and the substrate are heated by a substrate heating step performed to heat the substrate, and cooling means disposed in a position near the substrate and not in contact with the substrate. A cooling step to start cooling of the substrate and the substrate holding means to absorb the radiant heat from the holding means, and a substrate cleaning step of cleaning a substrate by radiating an ion to the substrate, the temperature of the substrate and 100 to 120 ° C., and a dielectric layer forming step of depositing a pre Symbol dielectric layer on the substrate, and the substrate heating stop step of stopping the heating of the substrate, the temperature of the substrate and 25 to 70 ° C., the And a reflective layer forming step of depositing the reflective layer on the dielectric layer in this order.

As described above, in the present invention, prior to the dielectric layer forming step and further the substrate cleaning step, a step of absorbing the radiant heat from the substrate and the substrate holding means by the cooling means and cooling the substrate and the substrate holding means is provided. ing. Therefore, the substrate temperature does not rise excessively during the substrate cleaning and the dielectric layer formation, the cooling time until the reflective layer formation step is started can be further shortened, and the manufacturing efficiency can be further improved. .
In addition, since the substrate is cooled in the process of forming a plurality of dielectric layers, a dielectric layer having good film quality can be formed.

At this time, before the substrate cleaning step, the vacuum chamber further comprises a first determination step of determining whether or not more than 1 × 10 -3 ^Pa, the vacuum chamber at 1 × 10 -3 ^Pa or less In some cases, it is preferable to perform the substrate cleaning step.
Thus, the first determination step is provided before the substrate cleaning step, the substrate cleaning step is performed when the inside of the vacuum chamber is 1 × 10 ⁻³ Pa or less, and the dielectric layer formation is performed following the substrate cleaning step. When the film is started, a dielectric layer having a good film quality can be formed. As a result, a high reflectance can be obtained by combining with a reflective layer. On the other hand, when the pressure in the vacuum chamber when forming the dielectric layer is higher than 1 × 10 ⁻³ Pa, it is difficult to obtain a dielectric layer with good film quality, and when combined with the reflective layer It becomes difficult to obtain a high reflectance.

Furthermore, prior to the reflective layer forming step, the substrate further comprises a second determination step of determining whether the temperature of the substrate is 50 ° C. or lower and the inside of the vacuum chamber is 3 × 10 ⁻⁴ Pa or lower. When the temperature is 50 ° C. or lower and the inside of the vacuum chamber is 3 × 10 ⁻⁴ Pa or lower, it is preferable to perform the reflective layer forming step.
As described above, the second determination step is provided before the reflective layer forming step, and the reflective layer is formed only when the temperature of the substrate is 50 ° C. or lower and the inside of the vacuum chamber is 3 × 10 ⁻⁴ Pa or lower. By setting it as the structure where a process is performed, the reflection layer provided with the high reflectance can be formed. On the other hand, when the substrate temperature is higher than 50 ° C., or when the pressure in the vacuum chamber at the time of forming the reflective layer is higher than 3 × 10 ⁻⁴ Pa, the reflectance of the reflective layer becomes low, which is favorable. It is difficult to obtain a reflective layer.

The second determination step includes a vacuum pump connected to the vacuum chamber via a vacuum valve, a pressure control means connected to the vacuum valve, a thermometer installed in the vicinity of the substrate, and the cooling Temperature control means connected to the control means, and the reflection layer forming step is a control in which the pressure control means and the shutter control means connected to the temperature control means open the shutter disposed on the evaporation source. It is suitable to be performed by performing.
Thus, when the pressure control means monitors the pressure in the vacuum chamber and automatically opens and closes the vacuum valve to control the pressure in the vacuum chamber, the workability is improved and the manufacturing is improved. Efficiency can be improved.
Furthermore, when the substrate temperature is monitored by the temperature control means and the cooling means is controlled by the cooling means, the workability is improved and the manufacturing efficiency can be improved.
Then, the pressure in the vacuum chamber and the substrate temperature are monitored by each control means, and when each is below a predetermined condition, the shutter is opened by the shutter control means connected to the pressure and temperature control means, Work efficiency can be further improved. In addition, the semiconductor light-emitting element substrate can be manufactured under uniform conditions without the operator misidentifying each condition and forming each layer.

According to the method for manufacturing a semiconductor light-emitting element substrate according to claim 1, since the time for cooling the substrate is shortened before the formation of the reflective layer is started, the manufacturing efficiency can be improved. Further, by providing a pressure condition and a temperature condition suitable for forming the reflective layer and the dielectric layer, a semiconductor light emitting element substrate having a high reflectance can be provided.
According to the method for manufacturing a semiconductor light-emitting element substrate according to claim 2, since the substrate is cooled even when the substrate is washed or when the dielectric layer is formed, the time for cooling the substrate before starting the formation of the reflective layer is started. Is further shortened. Further, by providing a pressure condition and a temperature condition suitable for forming the reflective layer and the dielectric layer, a semiconductor light emitting element substrate having a high reflectance can be provided.
According to the method for manufacturing a semiconductor light emitting element substrate according to claim 3, it is possible to form a dielectric layer having a good film quality.
According to the method for manufacturing a semiconductor light emitting element substrate according to the fourth aspect, it is possible to form a reflective layer having a good film quality.
According to the method for manufacturing a semiconductor light emitting element substrate according to the fifth aspect, by using aluminum as the material for forming the reflective layer, it is possible to form a reflective layer having a higher reflectance.
According to the method for manufacturing a semiconductor light-emitting element substrate according to the sixth aspect, the reflectance can be further improved by alternately combining the high refractive index layer and the low refractive index layer in each dielectric layer.
According to the method for manufacturing a semiconductor light emitting device substrate according to the seventh aspect, the operator does not need to monitor and control the pressure in the vacuum chamber and monitor and control the substrate temperature, so that the working efficiency is improved. In addition, since the operator does not mistake the pressure in the vacuum chamber and the substrate temperature to start forming each layer, a semiconductor light emitting device substrate having a reflective layer and a dielectric layer of uniform quality is manufactured. Can do.

It is explanatory drawing which shows the thin film forming apparatus which concerns on one Embodiment of this invention. It is explanatory drawing which shows the thin film forming apparatus which concerns on other embodiment of this invention. 1 is a schematic cross-sectional view of a semiconductor light emitting element substrate according to an embodiment of the present invention. It is a flowchart figure of the manufacturing process of the semiconductor light-emitting device substrate which concerns on one Embodiment of this invention. It is a flowchart figure of the manufacturing process of the semiconductor light-emitting device substrate which concerns on other embodiment of this invention. It is a graph which shows the relationship between the manufacture time of the semiconductor light-emitting device substrate which concerns on the Example of this invention, and substrate temperature. It is a graph which shows the relationship between the wavelength of a reflection layer which laminated | stacked the dielectric material from which a refractive index differs, and a reflectance.

1 Ion assisted vapor deposition equipment (thin film forming equipment)
2 Vacuum chamber 3 Substrate holder (substrate holding means)
3a Through-hole 3b Mounting member 4 Substrate holder rotating shaft 5 Substrate holder rotating motor 6 Evaporation source 7 Ion source 8 Heating means 11 Refrigerator (cooling means)
12 Refrigerant pipe (cooling means)
13 Cooling plate (cooling means)
13a Proximity cooling surfaces 17, 18 Mounting jig 20 Compressor 21 Cooling solenoid valve 22 Water cooling condenser 23 Thaw solenoid valve 24 Temperature control means 25 Thermometer 26 Heat exchanger 31 Vacuum valve 32 Pressure gauge 33 Vacuum pump 34 Pressure control means 43 Upper part Cooling plate (cooling means)
43a Proximity cooling surface 44 Bottom cooling plate (cooling means)
44a Evaporation source side cooling surface 44b Opening (evaporation source through opening)
44c Opening (Ion source through opening)
45 Side cooling plate (cooling means / protection plate)
45a Side wall cooling surface 46 Refrigerant tube 100 Buffer layer 110 N-type GaN layer 120 Light-emitting layer 130 p-type GaN layer 210 n-electrode 230 p-electrode S Substrate P Deposited material R Reflective layer H High-index dielectric layer L Low-index dielectric Body layer

  An embodiment of the present invention will be described below with reference to the drawings. It should be noted that members, arrangements, and the like described below do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.

FIG. 1 is an explanatory view of an ion-assisted vapor deposition apparatus 1 which is a kind of thin film forming apparatus, and shows a part of the apparatus as a cross section.
As shown in this figure, an ion-assisted vapor deposition apparatus 1 includes a vacuum chamber 2, a substrate holder 3, a substrate holder rotating shaft 4, a substrate holder rotating motor 5, an evaporation source 6, an ion source 7, and heating means. 8, a refrigerator 11, a refrigerant pipe 12, and a cooling plate 13 are provided as main components.

The vacuum chamber 2 is a container for forming a film inside. The vacuum chamber 2 of this embodiment is a hollow body having a substantially cylindrical shape, and a thin film can be formed by arranging the substrate S. A vacuum pump 33 is connected to the vacuum chamber 2, and the vacuum pump 33 exhausts the inside of the vacuum chamber 2 so that the inside of the vacuum chamber 2 is about 1 × 10 ⁻² to 1 × 10 ⁻⁵ Pa. The vacuum state can be achieved.
Further, the vacuum chamber 2 is formed with a gas introduction pipe (not shown) for introducing a gas therein.

  Examples of the material of the vacuum chamber 2 include metal materials such as aluminum and stainless steel. In this embodiment, SUS304 which is a kind of stainless steel is used.

  The substrate holder 3 is a member for holding the substrate S provided inside the vacuum chamber 2. The substrate holder 3 of the present embodiment is configured by a flat plate-like member, but may be configured by a dome-shaped member having a predetermined curvature. The substrate holder 3 corresponds to the substrate holding means of the present invention.

  The substrate holder 3 is formed with a through hole 3a penetrating from one plate surface to the other plate surface. The board | substrate S is attached to the board | substrate holder 3 using the attachment member 3b so that this through-hole 3a may be plugged up.

  The mounting member 3b of the present embodiment has a disk shape with a larger diameter than the through hole 3a of the substrate holder 3, and a part of the disk surface is recessed downward. An opening is formed in the recessed portion. The substrate S is attached to the substrate holder 3 by first placing the attachment member 3b in the through hole 3a of the substrate holder 3, and then placing the substrate S in the concave portion of the attachment member 3b with the film formation surface facing down. Put. Thus, in this embodiment, the substrate S can be easily set by simply placing the mounting member 3b and the substrate S on the substrate holder 3. The substrate S may be fixed to the attachment member 3b so that the substrate S does not move when the substrate holder 3 rotates.

  One end side of a rod-shaped substrate holder rotating shaft 4 is connected to the center of the substrate holder 3 in a direction perpendicular to the plate surface of the substrate holder 3. The other end side of the substrate holder rotating shaft 4 extends through the wall surface of the vacuum chamber 2 to the outside of the vacuum chamber 2 and is connected to the output shaft of the substrate holder rotating motor 5.

The substrate holder rotation motor 5 is a device for rotating the substrate holder 3. The substrate holder rotation motor 5 is provided outside the vacuum chamber 2. The output shaft of the substrate holder rotation motor 5 coincides with the axis of the substrate holder rotation shaft 4, and the rotation output of the substrate holder rotation motor 5 is transmitted to the substrate holder 3 via the substrate holder rotation shaft 4 to be transmitted to the substrate holder 3. Rotates.
The output shaft of the substrate holder rotating motor 5 is vacuum sealed by means such as a magnetic seal bearing (not shown).

  The board | substrate S is a member used as the foundation on which each layer is formed in the surface. In the present invention, it is preferable to use a highly versatile sapphire substrate as the substrate S of the semiconductor light emitting element substrate, but other suitable materials can be used as the material of the semiconductor light emitting element substrate.

  Further, in the present embodiment, a flat plate is used as the shape of the substrate S, but the present invention is not limited to this, and a substrate having an appropriate shape can be used as a substrate on which the semiconductor light emitting element substrate is formed.

  The evaporation source 6 is an evaporation unit that is disposed on the lower side inside the vacuum chamber 2 and emits a deposition material P, that is, a high refractive index material, a low refractive index material, and a metal (Al, Ag, etc.) toward the substrate S. is there. The evaporation source 6 includes an evaporation boat having an indentation for placing the deposition material P thereon, and an electron gun that irradiates the deposition material P with an electron beam to evaporate it. Further, in the present embodiment, a shutter (not shown) provided rotatably is provided at a position where the vapor deposition material P heading from the evaporation boat toward the substrate S is blocked. The shutter is appropriately opened and closed by a shutter control means (not shown).

In the present embodiment, a general device used in a vapor deposition apparatus is employed as the evaporation source 6. That is, a plurality of cylindrical hearth liners are provided as evaporation boats, and these hearth liners are arranged in concentric depressions of the disk-shaped hearth. The disk-shaped hearth is formed of a metal having high thermal conductivity such as copper and is directly or indirectly cooled by a water cooling device (not shown). Each hearth liner contains the vapor deposition material P. When the vapor deposition material P of one hearth liner runs out, the disk-shaped hearth rotates to evaporate the vapor deposition material P of the next hearth liner.
Since the disk-shaped hearth itself is water-cooled, it is difficult to serve as a heat source. However, since the vapor deposition material P remaining on the hearth liner is usually an oxide, its thermal conductivity is low and it is difficult to be cooled. For this reason, the vapor deposition material P on the hearth liner becomes a heat source for heating the substrate S by radiant heat.

When a vapor deposition material P as a thin film raw material is placed on the evaporation boat, an electron beam of about 1 to 3 kW is generated, and when this is irradiated to the vapor deposition material P, the vapor deposition material P is heated and evaporates. When a shutter (not shown) is opened in this state, the vapor deposition material P evaporated from the evaporation boat moves inside the vacuum chamber 2 toward the substrate S and adheres to the surface of the substrate S. During the film formation, the temperature of the evaporation source 6 rises to 1500 to 2500 ° C.
Further, since the evaporation source 6 is preheated even when the shutter is closed other than during film formation because the vapor deposition material P is dissolved, the temperature of the shutter and its surroundings also rises.
The evaporation source 6 is not limited to an apparatus that is evaporated by such an electron gun, and may be an apparatus that evaporates the vapor deposition material P by resistance heating, for example.

  The semiconductor optical element formed in this embodiment is formed by alternately stacking a high refractive index material and a low refractive index material and further stacking a reflective layer R thereon (see FIG. 3). ), Depending on the type and number of the vapor deposition material P, the number and arrangement of the evaporation sources 6 can be appropriately changed.

The ion source 7 is a device for irradiating positive ions toward the substrate S, and ions (O ₂ ⁺ , Ar ⁺ ) charged from plasma of a reactive gas (for example, O ₂ ) or a rare gas (for example, Ar) are used. Extracted and accelerated by acceleration voltage. As the ion source 7, a well-known thing generally used in a vacuum evaporation system can be used.

The vapor deposition material P moving from the evaporation source 6 toward the substrate S adheres to the surface of the substrate S with high density and strength due to the collision energy of positive ions irradiated from the ion source 7. At this time, the substrate S is positively charged by positive ions contained in the ion beam.
If necessary, a neutralizer that neutralizes charges by irradiating a positively charged substrate S or substrate holder 3 with an electron beam may be provided.

  In this embodiment, the surface of the substrate S is previously ion-cleaned by ions emitted from the ion source 7, and then each layer is formed.

  In the present embodiment, heating means 8 is provided below the substrate holder 3. The heating means 8 is a heating source for heating the substrate S by radiant heat. In addition, as such a heating means 8, well-known things, such as a halogen lamp and an infrared heater, are used. Further, the heat generation amount of the heating unit 8 may be controlled by the temperature control unit 24 based on a temperature measured by a thermometer 25 described later.

  The pressure inside the vacuum chamber 2 is measured and displayed by the pressure gauge 32, and a desired pressure can be controlled by the pressure control means 34. That is, the internal pressure measured by the pressure gauge 32 is monitored by the pressure control means 34 connected to the pressure gauge 32, and the vacuum valve 31 connected to the pressure control means 34 is closed when the pressure becomes lower than a predetermined pressure. As a result, exhaust by the vacuum pump 33 is not performed. Moreover, it is good also as a structure provided with MV (miniature valve) not shown in the vacuum chamber 2 side.

On the other hand, in a state where the pressure is not reduced to a desired pressure, the vacuum valve 31 connected to the pressure control means 34 is opened, and the vacuum pump 33 performs evacuation. Thus, the internal pressure of the vacuum chamber 2 is monitored by the pressure control means 34, and the pressure in the vacuum chamber 2 can be controlled to a predetermined value.
In the vacuum chamber 2, the portion where the pressure gauge 32 is disposed is vacuum-sealed. Moreover, a well-known thing can be used for the pressure gauge 32, the vacuum valve 31, and the vacuum pump 33, respectively.

Next, the cooling means of this embodiment will be described.
The cooling means is means for cooling the substrate S and maintaining the temperature at an appropriate temperature. The cooling means includes the refrigerator 11, the refrigerant pipe 12, and the cooling plate 13 as main components.

A cooling plate 13 is disposed inside the vacuum chamber 2. The cooling plate 13 has a disk shape and is disposed along the upper surface of the substrate holder 3. That is, the cooling plate 13 is disposed on the opposite side of the substrate holder 3 from the side where the evaporation source 6 is provided. The cooling plate 13 is made of a metal material having high thermal conductivity such as copper or aluminum.
The cooling plate 13 may not be a complete plate shape, but may be a plate shape having a hole or a strip shape in view of the temperature of the substrate holder 3 and the substrate S, the performance of the refrigerator 11 and the like.

  Of the cooling plate 13, the center side of the vacuum chamber 2, that is, the surface on which the substrate S is disposed constitutes the proximity cooling surface 13 a of the present invention. Further, the refrigerant pipe 12 is in contact with the surface opposite to the proximity cooling surface 13a. Therefore, the surface of the cooling plate 13 that contacts the refrigerant tube 12 is cooled by the refrigerant flowing through the refrigerant tube 12, and the adjacent cooling surface 13a formed on the opposite surface is also cooled.

  The cooling plate 13 is fixed in the vacuum chamber 2 using a mounting jig 17. There is a gap between the cooling plate 13 and the substrate holder rotating shaft 4 so that the substrate holder rotating shaft 4 can rotate smoothly. In order to prevent heat from flowing in from the substrate holder rotating shaft 4 due to heat conduction, a material having a low thermal conductivity is sandwiched in the middle of the substrate holder rotating shaft 4 or the substrate holder rotating shaft 4 is cooled. A cooling plate may be arranged.

  Further, a bearing or the like is provided between the wall surface of the cooling plate 13 and the outer peripheral surface of the substrate holder rotating shaft 4 to smoothly rotate the substrate holder rotating shaft 4, and heat is moved along the substrate holder rotating shaft 4. You may make it difficult.

  The refrigerant pipe 12 is constituted by a hollow tubular member, and has a role as a cryocoil for cooling a cooling plate 13 described later. One end of the refrigerant pipe 12 is connected to the discharge port of the refrigerator 11 and the other end is connected to the inflow port, and is introduced into the vacuum chamber 2. And it is comprised so that a refrigerant | coolant may be circulated through the refrigerator 11 by making the refrigerant | coolant discharged from the refrigerator 11 flow from one end side to the other end side.

  The refrigerant pipe 12 is wound in a spiral shape so that the refrigerant inflow side is on the outside and the delivery side is on the inside, and is fixed in contact with the outer flat surface of the disk-shaped cooling plate 13. In addition, as a form which fixes the refrigerant | coolant pipe | tube 12, it is not limited to such a spiral form, Spiral form, meandering form, etc. may be sufficient.

  The refrigerator 11 is a device for cooling the refrigerant and supplying the refrigerant to the refrigerant pipe 12 for circulation. The refrigerator 11 of the present embodiment uses a known refrigeration apparatus in which the refrigerant pipe 12 is a cryocoil.

  More specifically, the refrigerator 11 includes a compressor 20 that compresses a refrigerant (gas refrigerant), a water-cooled condenser 22 that cools the refrigerant from the compressor 20 by heat exchange with cooling water, and a refrigerant that is cooled with compressed water. And a cooling solenoid valve 21 and a thawing solenoid valve 23 provided on the discharge port side of the refrigerator 11. An expansion valve (not shown) is provided inside the heat exchanger 26.

  And the refrigerant | coolant pipe | tube 12 as a cryocoil is cooled by flowing the refrigerant | coolant cooled with the refrigerator 11 to the refrigerant | coolant pipe | tube 12. FIG. The refrigerant in the refrigerant pipe 12 rises in temperature in the vacuum chamber 2 and partially evaporates, and circulates to the refrigerator 11 as a high-temperature gas refrigerant. The gas refrigerant is compressed by the compressor 20, cooled again by the water-cooled condenser 22 and the heat exchanger 26, becomes a low-temperature refrigerant, and is sent out again from the discharge port to the refrigerant pipe 12.

The refrigerator 11 is provided with an inflow port through which the gas refrigerant circulated through the refrigerant pipe 12 flows. The high-temperature gas refrigerant flowing in from the inlet is cooled again in the refrigerator 11.
Further, by closing the cooling solenoid valve 21 and opening the thawing solenoid valve 23, the gas refrigerant compressed by the compressor 20 (hereinafter referred to as “heating gas”) does not pass through the water-cooled condenser 22. By flowing directly through the refrigerant pipe 12, the temperature of the cryocoil can be rapidly increased to about room temperature.

A cooling solenoid valve 21 and a thawing solenoid valve 23 are provided on the discharge port side of the refrigerator 11. Each solenoid valve 21, 23 is a valve that includes two valves and can be switched by electromagnetic control.
The cooling solenoid valve 21 is provided in the middle of a line for supplying the refrigerant from the heat exchanger 26 to the refrigerant pipe 12. The thawing solenoid valve 23 is provided in the middle of a branch line that branches from the above line and is connected to the output side line of the compressor 20.

  The refrigerator 11 can take three modes. That is, both the solenoid valves 21 and 23 are closed so that neither the refrigerant nor the heated gas is supplied to the refrigerant pipe 12, and only the cooling solenoid valve 21 is opened and the refrigerant is supplied to the refrigerant pipe 12. “Mode” is a “thaw mode” in which only the thawing solenoid valve 23 is opened and the heated gas is supplied to the refrigerant pipe 12.

Before the start of cooling, the mode of the refrigerator 11 is set to “standby mode”, and both the cooling solenoid valve 21 and the thawing solenoid valve 23 are closed.
When the cooling plate 13 is cooled by the refrigerator 11, the mode of the refrigerator 11 is set to “cooling mode”, the cooling solenoid valve 21 is opened, and the thawing solenoid valve 23 is kept closed. Thereby, for example, the refrigerant cooled to −100 ° C. or lower flows into the refrigerant pipe 12, and the cooling plate 13 is cooled to −100 ° C. or lower.

  On the other hand, when the ion-assisted vapor deposition apparatus 1 is opened to the atmosphere, the temperature of the cooling plate 13 needs to be about room temperature of 0 ° C. or higher. Therefore, the mode of the refrigerator 11 is set to “thawing mode”, and the cooling solenoid valve 21 is turned on. Close and open the thawing solenoid valve 23. Thereby, heated gas is supplied to the refrigerant pipe 12 and the temperature of the cooling plate 13 rises.

A thermometer 25 for measuring the temperature of the substrate S is disposed close to the substrate S. The thermometer 25 can use a known temperature measuring means such as a thermocouple.
The thermometer 25 is connected to the temperature control means 24. The temperature control means 24 is also connected to an electromagnetic valve for controlling the opening and closing of the cooling solenoid valve 21 and the thawing solenoid valve 23 of the refrigerator 11, and appropriately changing the opening / closing state of each of the substrates S by the cooling plate 13. The cooling temperature is adjusted.
With this configuration, the temperature can be kept constant by changing the supply power according to the film formation conditions during film formation.

  The refrigerator 11 can perform any one of a “standby mode”, a “cooling mode”, and a “thawing mode” according to the operation state of the apparatus. The temperature of the cooling plate 13 can be measured by detecting the temperature of the refrigerant returning to the refrigerator 11 with a thermometer (not shown) provided in the refrigerator 11. Based on the preset cooling plate temperature, the operating state of the refrigerator in the “cooling mode” can be controlled, and the temperature of the cooling plate 13 can be controlled.

  Since the proximity cooling surface 13a is provided at a position close to the substrate S, it absorbs the radiant heat from the substrate S and the substrate holder 3 and cools it. That is, the amount of heat radiated from the high temperature substrate S and the substrate holder 3 is larger than the amount of heat radiated from the low temperature proximity cooling surface 13a, so that heat is transferred from the substrate S or the substrate holder 3 to the proximity cooling surface 13a. As a result, radiation cooling occurs, and the substrate S and the substrate holder 3 are cooled.

  By providing such a configuration, the cooling plate 13 can cool the substrate S from above the substrate holder 3. For this reason, the temperature rise of the substrate S can be suppressed, and a desired substrate temperature can be maintained during film formation. Furthermore, even when the substrate temperature rises during film formation, the cooling time can be effectively shortened because the substrate S is cooled.

Further, since the substrate S is mounted on the attachment member 3b and attached to the substrate holder 3, the upper and lower surfaces of the substrate S are exposed to the outside, and the space between the exposed surface of the substrate S and the adjacent cooling surface 13a is shielded. There is nothing. For this reason, the radiant heat smoothly moves from the substrate S to the adjacent cooling surface 13a, and the substrate S can be efficiently cooled.
Furthermore, in order to cool the substrate S uniformly, the entire surface of the substrate S may be covered with a covering member formed of substantially the same material as the substrate holder 3. In this case, it is preferable that the covering member and the substrate holder 3 have substantially the same heat emissivity, and the total heat capacity obtained by adding the respective heat capacities of the substrate S and the covering member is substantially the same as the heat capacity of the substrate holder 3.

Next, heat transfer in the vacuum chamber 2 of FIG. 1 will be described.
Since the cooling plate 13 and the substrate holder 3 are installed close to each other, they may be considered as substantially parallel plates. The heat transfer by the radiant heat per unit area of the parallel plate is expressed by the following formula 3.
Q = εsσT _s ⁴ −εcσT _c ⁴ (Expression 3)
Here, Q is the amount of heat, εs is the heat radiation rate of the substrate S, εc is the heat radiation rate of the cooling plate 13, σ is the Stefan-Boltzmann constant, Ts is the absolute temperature [K] of the substrate S, and Tc is the cooling plate 13. Absolute temperature [K].

Since εs and εc are in the same order, if Tc is sufficiently lower than Ts, heat flows unilaterally from the substrate S to the cooling plate 13. This effect is, for example, a cooling effect of about 1 kW per 1 m ^{2 on} one side of the cooling plate 13 when Ts is 100 ° C., and the temperature of the substrate S is 30 ° C. or higher compared to the case where there is no cooling plate 13. Can be lowered. Since the cooling plate 13 absorbs heat on both upper and lower surfaces, the cooling capacity of the cooling plate 13 may be about 2 kW.

  Since the evaporation source 6 is a heat source of 1 to 3 kW and the ion source 7 is a heat source of 0.5 to 1.5 kW, if the cooling effect is insufficient with only the cooling plate 13 (upper cooling plate 43 in FIG. 2), By installing the bottom cooling plate 44 and the side cooling plate 45 as in the other embodiments shown, the temperature of the substrate S can be more effectively lowered.

Next, a thin film forming apparatus according to another embodiment of the present invention will be described with reference to FIG. FIG. 2 is an explanatory diagram of a thin film forming apparatus 1 according to another embodiment of the present invention.
The thin film forming apparatus (ion-assisted vapor deposition apparatus) 1 of this embodiment includes a bottom cooling plate 44 and a side cooling plate 45 in addition to a cooling plate (upper cooling plate 43) provided on the upper surface side of the substrate holder 3. The feature is that the entire periphery of the substrate holder 3 is surrounded by a cooling plate.

  Inside the vacuum chamber 2, there is an upper cooling plate 43 disposed on the opposite side of the evaporation source 6 with the substrate holder 3 interposed therebetween, and a bottom cooling disposed at the bottom of the vacuum chamber 2. The plate 44 and the side cooling plate 45 arranged along the inner surface of the vacuum chamber 2 are main components.

  Among these, since the upper cooling plate 43 has the same configuration as the cooling plate 13 according to the first embodiment, the description thereof is omitted. That is, the upper cooling plate 43 constitutes a part of the cooling means of the present invention, and the surface on the substrate holder 3 side constitutes the proximity cooling surface 43a.

  The bottom cooling plate 44 constitutes a part of the cooling means of the present invention, and the surface on the substrate holder 3 side constitutes the evaporation source side cooling surface 44a. Further, the side cooling plate 45 constitutes a part of the cooling means of the present invention, and the surface on the substrate holder 3 side constitutes the side wall cooling surface 45a. Furthermore, the refrigerator 11 and the refrigerant pipe 12 correspond to the cooling means of the present invention.

  In the bottom cooling plate 44, an opening 44b (evaporation source through opening) for penetrating the evaporation source 6 and an opening 44c (ion source through opening) for penetrating the ion source 7 are formed. The evaporation source 6 is positioned in the region surrounded by the cooling plate 13 through the opening 44b and the ion source 7 through the opening 44c. As described above, the bottom cooling plate 44 is provided with the openings 44b and 44c so that the vapor deposition material P and the ion beam supplied from the evaporation source 6 and the ion source 7 to the substrate S are not obstructed.

  The side cooling plate 45 is detachably attached to the side inner wall surface of the vacuum chamber 2. The side cooling plate 45 also functions as an adhesion preventing plate. That is, the side cooling plate 45 has a function as a member that prevents the vapor deposition material P from the evaporation source 6 from adhering to the side inner wall surface of the vacuum chamber 2.

When the vapor deposition material P adheres to the side cooling plate 45 and the inside of the vacuum chamber 2 is contaminated, the side cooling plate 45 is removed from the vacuum chamber 2 and the surface is polished by sandblasting etc. P can be removed. Thereby, the inside of the vacuum chamber 2 can be made into a clean state.
Similarly to the side cooling plate 45, the bottom cooling plate 44 is also detachable and has a function as an adhesion preventing plate.

  A refrigerant tube 46 is in contact with the vacuum chamber 2 wall surface side of the upper cooling plate 43, the bottom cooling plate 44, and the side cooling plate 45. The refrigerant pipe 46 is a tubular member capable of allowing a refrigerant to flow inside, similarly to the refrigerant pipe 12 of the first embodiment.

  The refrigerant tube 46 is spirally wound on the upper plane of the upper cooling plate 43, then spirally wound around the outer peripheral surface of the side cooling plate 45, and spirally wound on the lower plane of the bottom cooling plate 44. ing. The discharge port side of the refrigerator 11 is connected to one end of the upper cooling plate 43, and the inlet side is fixed to one end of the bottom cooling plate 44. For this reason, the refrigerant supplied from the refrigerator 11 sequentially circulates through the upper cooling plate 43, the side cooling plate 45, and the bottom cooling plate 44, and returns to the refrigerator 11 again.

  In the present embodiment, the upper cooling plate 43, the bottom cooling plate 44, and the side cooling plate 45 are configured to surround the entire periphery of the substrate holder 3. That is, the bottom cooling plate 44 and the side cooling plate 45 absorb the heat of the evaporation source 6 and the ion source 7 and further absorb the radiant heat from the substrate holder 3, so that the cooling plate 13 is placed only above the substrate S. Compared to the above-described embodiment, the substrate S can be cooled more reliably.

  Both the bottom cooling plate 44 and the side cooling plate 45 are optional components of the present invention. These bottom cooling plate 44 and side cooling plate 45 do not use a special refrigerant depending on the heat-resistant temperature of the substrate S and the film forming conditions (input power conditions to the electron gun and ion source 7, film forming time, etc.) You may make it just cool by circulating water and cooling with water. Further, when the substrate S can be sufficiently cooled only by the upper cooling plate 43, the cooling by the bottom cooling plate 44 and the side cooling plate 45 may not be performed.

  Further, in the present embodiment, the refrigerator 11 that cools the upper cooling plate 43, the bottom cooling plate 44, and the side cooling plate 45 is a common device, but individual refrigeration for cooling each cooling plate 43-45. A machine may be provided.

  Next, the configuration of the semiconductor light emitting element substrate according to the embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view of a semiconductor light emitting device substrate according to an embodiment of the present invention.

  In general, in a semiconductor light emitting device, as shown in FIG. 3, a buffer layer 100, an n-type GaN layer 110, a light emitting layer 120, and a p-type GaN layer 130 are sequentially stacked on a substrate S made of sapphire or the like. A part of the n-type GaN layer 110 is removed stepwise by etching, and an n-electrode 210 is formed in the removed part. The p electrode 230 is formed on the p-type GaN layer 130.

On the other hand, on the substrate S, the dielectric layers H and L corresponding to the increased reflection layer and the reflection layer R are provided on the surface opposite to the surface on which the layers including the light emitting layer 120 are provided.
Hereinafter, the reflective layer R side in the substrate S of the semiconductor light emitting element substrate according to the embodiment of the present invention will be described.

  The dielectric layers H and L are formed by alternately stacking the high refractive index dielectric layer H and the low refractive index dielectric layer L on the substrate S. FIG. 3 shows a configuration in which a total of four dielectric layers H and L are stacked in order from the high refractive index dielectric layer H on the substrate S. However, any number of layers may be provided. Any structure may be used as long as a film composed of a substance having a relatively high refractive index and a substance having a low refractive index are alternately combined.

Examples of substances that form the high refractive index dielectric layer H include titanium oxide (TiO ₂ , refractive index 2.52), zirconium oxide (ZrO ₂ , refractive index 2.4), tantalum oxide (Ta ₂ O ₅ , the refractive index is 2.16), and niobium oxide (Nb ₂ O ₅ , the refractive index is 2.33). Examples of the material for forming the low refractive index dielectric layer L include aluminum oxide (Al ₂ O ₃ , refractive index 1.76), silicon oxide (SiO ₂ , refractive index 1.45), fluorine, and the like. Magnesium fluoride (MgF ₂ , refractive index 1.37).

  After the dielectric layers H and L having the above configuration are formed, the reflective layer R is formed. The reflective layer R is formed of a metal having high reflectivity, and for example, aluminum (Al), silver (Ag), or the like is used. When Al is used as the material of the reflective layer R, the substrate temperature during film formation and the pressure in the vacuum chamber 2 are largely related to the reflectance.

The dielectric layers H and L and the reflective layer R are formed by depositing various materials using the thin film forming apparatus 1 described above. Each film thickness is appropriately designed according to the desired reflectance. Further, when forming each dielectric layer H, L, the pressure in the vacuum chamber 2 is set to about 1 × 10 ⁻³ Pa or less, more preferably about 1 × 10 ⁻⁴ to 1 × 10 ⁻³ Pa. Dielectric layers H and L are formed. When forming the dielectric layers H and L, if they are formed under a pressure higher than 1 × 10 ⁻³ Pa, it is difficult to obtain the dielectric layers H and L having good film quality. At this time, it is preferable that the temperature of the substrate S is 100 to 120 ° C., preferably about 110 ° C., because the packing density of the dielectric layers H and L is increased.

When the reflective layer R is formed on each dielectric layer H, L using Al, the substrate temperature is 50 ° C. or lower and the pressure in the vacuum chamber 2 is 3 × 10 ⁻⁴ Pa or lower. To do. Thus, when the reflective layer R is formed using Al, when the temperature of the substrate S is about room temperature (25 ° C.) to 70 ° C., more preferably 25 ° C. to 50 ° C., the reflective layer having good reflectivity. R can be obtained. Further, when forming the reflecting layer R, the pressure in the vacuum chamber 2 in which the substrate S is disposed to the ^{1 × 10 -4 Pa~3 × 10 -4} Pa or so, the reflection layer of good reflectance R Can be obtained.
On the other hand, when the substrate temperature is higher than 70 ° C. or when the internal pressure is higher than 3 × 10 ⁻⁴ Pa, it is difficult to obtain the reflective layer R having a good reflectance.

  FIG. 3 shows an example in which the buffer layer 100, the n-type GaN layer 110, the light emitting layer 120, and the p-type GaN layer 130 are sequentially stacked on the substrate S, and the reflective layer R is formed on the side opposite to these semiconductor layers. However, the structure of the semiconductor layer is not limited to this. Of course, a semiconductor layer made of other materials may be provided in a configuration different from that shown in FIG. 3 as long as it functions as a semiconductor light emitting element.

  Next, a film forming process for forming the dielectric layers H and L and the reflective layer R having the above-described structure using the thin film forming apparatus 1 of the present embodiment will be described with reference to FIGS. 4 and 5. 4 and 5, there are portions where the order of each process is different, but the order is appropriately selected depending on the material, film thickness, and the like of each of the dielectric layers H and L.

First, a manufacturing process of a semiconductor light emitting element substrate according to an embodiment of the present invention will be described with reference to FIG. FIG. 4 is a flowchart of a manufacturing process of a semiconductor light emitting device substrate according to an embodiment of the present invention.
In this manufacturing process, first, the substrate S (see FIG. 3) is set on the substrate holder 3 with the surface on which the reflective layer R is formed facing down, and the door of the vacuum chamber 2 is closed (substrate holding step S1). Next, the vacuum valve 31 is opened, and the vacuum chamber 2 is evacuated (evacuation step S2). This operation may be performed by the pressure control means 34.

  In the substrate holding step S1, the substrate S is set on the substrate holder 3 with the surface on which the reflective layer R is formed facing the evaporation source 6 side. More specifically, the substrate S (see FIG. 3) on which the buffer layer 100, the n-type GaN layer 110, the light emitting layer 120, and the p-type GaN layer 130 are sequentially stacked and the electrodes 210 and 230 are formed is connected to each semiconductor layer. Is set in the substrate holder 3 with the surface on which no is formed facing downward.

  Regarding the formation of each semiconductor layer, a step of forming each semiconductor layer on one surface of the substrate S is provided before the substrate holding step S1, or each semiconductor layer is formed after the reflective layer forming step S10. A process may be provided. However, generally, since the formation of each semiconductor layer composed of a GaN-based compound requires severe conditions, after each semiconductor layer is formed on the substrate S in advance, each dielectric layer is formed on the back surface of each semiconductor layer. It is preferable to perform the step of forming H, L and the reflective layer R.

After the vacuum chamber 2 is depressurized, heating by the heating unit 8 is started so that the substrate S reaches a set temperature (110 ° C. in this embodiment), and the temperature control unit 24 sets the temperature of the substrate S to the set temperature. It adjusts so that it may become (substrate heating process S3). At this time, it is preferable that the heating means 8 is also connected to the temperature control means 24. Further, it is only necessary that the temperature of the substrate S is controlled to be the set temperature before the dielectric layer forming step S7 is started.
As described above, it is preferable to perform film formation in a state where the substrate S is heated and held at a constant temperature because a filling density of the film formed on the substrate S is increased.

Thereafter, the pressure in the vacuum chamber 2 is measured and displayed by the pressure gauge 32, and it is determined by the pressure control means 34 whether the pressure is 1 × 10 ⁻³ Pa or less (first determination step S4).
In the first determination step S4, when the pressure in the vacuum chamber 2 does not reach 1 × 10 ⁻³ Pa or less (first determination step S4: No), the vacuum valve 31 is continuously kept open. The evacuation is continued by the vacuum pump 33.

On the other hand, when the pressure in the vacuum chamber 2 reaches 1 × 10 ⁻³ Pa or less (first determination step S4: Yes), the vacuum valve 31 is appropriately opened and closed by the pressure control means 34, and the vacuum pump 33 exhausts the air. The amount is controlled, and the inside of the vacuum chamber 2 is maintained at 1 × 10 ⁻³ Pa or less. Even when the inside of the vacuum chamber 2 reaches a predetermined pressure (first determination step S4: Yes), the vacuum valve 31 and an unillustrated MV (miniature valve) are maintained open, It is preferable that the exhaust is continued.

After the inside of the vacuum chamber 2 is maintained at 1 × 10 ⁻³ Pa or less, the substrate holder (substrate holding means) 3 holding the substrate S rotates (substrate holding means rotating step S5), and the ion source with respect to the substrate S 7 is irradiated with an ion beam. By irradiating the substrate S with an ion beam, contaminants attached to the surface of the substrate S, particularly hydrocarbon-based polymers can be effectively removed (substrate cleaning step S6). The substrate holding means rotation step S5 is not necessarily performed in this order, and is appropriately provided before and after other steps.

After cleaning the surface of the substrate S, the dielectric layers H and L having the above-described configuration are formed by vapor deposition (dielectric layer forming step S7). In the dielectric layer forming step S7, a shutter (in the vicinity of the evaporation source 6 that emits a high refractive index substance (for example, Ta ₂ O ₅ , TiO ₂ or the like) or a low refractive index substance (for example, SiO ₂ or the like)). By controlling the opening and closing of the material (not shown), the high refractive index substance and the low refractive index substance are alternately emitted toward the substrate S.

While discharging these vapor deposition materials P, the surfaces of the dielectric layers H and L attached to the substrate S are smoothed by colliding ions (for example, O ₂ ⁺ and Ar ⁺ ) with the substrate S from the ion source 7. And densify. By repeating this operation a predetermined number of times, a multilayer film is formed.
At this time, the bias of the substrate S is caused by the irradiation of the ion beam. The bias of the charge is preferably neutralized by irradiating electrons from the neutralizer (not shown) toward the substrate S. .

  Thereafter, the heating of the substrate S is ended, and the refrigerator 11 that has been operated in the standby mode in advance is set in the cooling mode to start the cooling (cooling step S9). After the ion cleaning (substrate cleaning step S6) and the formation of the dielectric layers H and L (dielectric layer forming step S7), the substrate S reaches a high temperature of 100 ° C. or higher. Accordingly, the substrate heating stop process S8 and the cooling process S9 for stopping the heating of the substrate S are provided, and the substrate S is cooled by using the cooling means 11, 12, and 13, so that it is suitable for the subsequent formation of the reflective layer R. It can be quickly cooled down to the substrate temperature. In FIG. 4, the order of the substrate heating stop step S8 and the cooling step S9 may be first, but the substrate heating stop step S8 is preferably performed first in order to reduce power consumption.

  The substrate S is cooled until the reflection layer forming step S11 is completed. As described above, it is preferable to form the reflective layer R while cooling because the reflective layer R having a higher reflectance can be formed.

And the temperature of the board | substrate S is measured with the thermometer 25, and it is judged by the temperature control means 24 whether the board | substrate temperature became 50 degrees C or less (2nd judgment process S10). Even if the substrate temperature is 50 ° C. or lower, the pressure control means 34 determines whether or not the pressure in the vacuum chamber 2 is 3 × 10 ⁻⁴ Pa or lower (second determination step) S10) The process proceeds to the next step only when both the substrate temperature and the internal pressure condition are satisfied (second determination step S10: Yes).

At this time, it is preferable that a predetermined temperature (50 ° C. in the present embodiment) is input in advance to the temperature control means 24 and it is determined whether or not the temperature has become equal to or lower than the predetermined temperature. In addition, predetermined pressures (1 × 10 ⁻³ Pa and 3 × 10 ⁻⁴ Pa in the present embodiment) are input to the pressure control unit 34 in advance, and it is determined whether or not the pressure is equal to or lower than the predetermined pressure in each of the determination steps S4 and S10. It is preferable that the configuration is determined.

When the substrate temperature does not reach 50 ° C. or lower (second determination step S10: No), it is difficult to obtain a good reflectance in the reflective layer R. Therefore, the cooling of the substrate S is continued, and the determination in step S10 is repeated. Further, even when the inside of the vacuum chamber 2 does not reach 3 × 10 ⁻⁴ Pa or less (second determination step S10: No), it is difficult to obtain a good reflectance in the reflective layer R. Therefore, if the vacuum valve 31 and the MV (not shown) are opened during the reflective layer forming step S11, the vacuum evacuation is continued and the pressure in the vacuum chamber 2 is maintained at 3 × 10 ⁻⁴ Pa or less. A reflective layer R with good film quality is formed.

  In the second determination step S10, only when both the substrate temperature and the internal pressure condition are satisfied, the reflective layer R is formed on the dielectric layers H and L (reflective layer forming step S11). At this time, when the temperature control means 24 and the pressure control means 34 and the shutter control means for controlling the open / close state of a shutter (not shown) installed on the evaporation source 6 are connected to each other, and the above two conditions are satisfied. The shutter may be automatically opened and the reflective layer R may be formed. Then, after the reflective layer R reaches a predetermined film thickness, a shutter (not shown) is closed, and the substrate S is appropriately cooled by a cooling mechanism, and the film forming operation is completed. Note that a step of further forming a protective film may be provided after the formation of the reflective layer R made of aluminum or the like.

  When the film forming operation is completed through the above steps, the refrigerator 11 is operated in the thawing mode, and the temperature of the cooling plate 13 is raised to room temperature. Thereafter, a leak valve (not shown) is opened to introduce an inert gas or the like, and the inside of the vacuum chamber 2 is set to atmospheric pressure (leak process S12). Then, the substrate S is taken out from the substrate holder 3. In the leakage step S12, the gas refrigerant flowing through the cooling means 11, 12, and 13 is not passed through the heat exchanger 26 but directly from the compressor 20 to the cooling plate 13 (the respective cooling plates 43 to 45). It is possible to return the cooling plate to room temperature.

  Through the above steps, the dielectric layers H and L and the reflective layer R of the semiconductor light emitting element substrate of the present invention are formed. In addition, although description of the process of arrange | positioning the substance vapor-deposited on the board | substrate S in the said process, ie, the material substance of each dielectric material layer H and L, and the reflection layer R was abbreviate | omitted, the board | substrate S is mounted in the board | substrate holder 3. Appropriately performed before and after.

  In addition, it is preferable to appropriately provide a preliminary heating step for the evaporation source 6 and the ion source 7 before the substrate cleaning step S6 for performing ion cleaning.

  Next, a manufacturing process of a semiconductor light emitting element substrate according to another embodiment of the present invention will be described with reference to FIG. FIG. 5 is a flowchart of a manufacturing process of a semiconductor light emitting device substrate according to another embodiment of the present invention. Since the substrate holding step S1 to the first determining step S4 in FIG. 4 and the substrate holding step S101 to the substrate heating step S103 shown in FIG. 5 have the same configuration, description thereof is omitted.

  In the manufacturing process of the semiconductor light emitting element substrate shown in FIG. 5, after the substrate heating process S103 for starting the heating of the substrate S, a cooling process S104 for starting the cooling of the substrate S is performed. The operation of the refrigerator 11 at this time is the same as that in the cooling step S9 in FIG.

  As described above, unlike the manufacturing process of the semiconductor light emitting element substrate shown in FIG. 4, the power consumption is increased by providing the cooling step S104 at an early stage, but the cooling means 11, 12, 13 (and 43, 44) can be operated stably, and since the cooling means 11, 12, 13 (and 43, 44) are operating in advance, the cooling time of the substrate S can be shortened. Can do.

After the cooling of the substrate S is started in the cooling step S104, it is determined in the first determination step S105 whether the inside of the vacuum chamber 2 is 1 × 10 ⁻³ Pa or less (first determination step S105). In the first determination step S105, after it is determined that the inside of the vacuum chamber 2 is 1 × 10 ⁻³ Pa or less, the dielectric layers H and L are formed in this embodiment. In the first determination step S105, it is also determined whether or not the temperature of the substrate S is maintained at a set temperature (about 110 ° C. in the present embodiment), and the substrate temperature is maintained at a predetermined temperature. After the determination, it is preferable to proceed to the next step.

  Thereafter, the substrate holder (substrate holding means 3) holding the substrate S rotates (substrate holding means rotating step S106), and the substrate S is irradiated with an ion beam from the ion source 7 (substrate cleaning step S107). As described above, when the substrate S is cooled by the refrigerator 11 even during ion cleaning of the substrate S, the temperature of the substrate S does not increase excessively, and the cooling time can be shortened. Note that the substrate holding means rotating step S106 is not necessarily performed in this order, and is appropriately provided before and after other steps.

  Although the substrate S is cooled during the substrate cleaning step S107, the substrate S is heated and maintained at approximately 110 ° C. Therefore, in the next dielectric layer forming step S108, the dielectric layers H, L can form a layer having good film quality. Since the substrate S is also cooled during the dielectric layer forming step S108, the temperature of the substrate S does not rise excessively even during the formation of the dielectric layers H and L, and the dielectric layers H and L The cooling time during film formation is greatly reduced.

  Further, as shown in FIG. 7, each of the dielectric layers H and L can obtain a high reflectance in the reflective layer R when the number of layers is large, but the substrate temperature inevitably increases when the number of layers is large. It's easy to do. Therefore, as shown in FIG. 5, a cooling step S104 for starting the cooling of the substrate S is performed before the dielectric layer forming step S108 for forming the dielectric layers H and L, whereby each dielectric layer H , L can be prevented from increasing even if the number of L is relatively large.

  Regarding the cooling step S104, the cooling may be performed until the substrate S is formed, or may be performed until the formation of the reflective layer R is completed. By continuing cooling until the formation of the reflective layer R is completed, it is possible to form the reflective layer R with good film quality.

  Therefore, even if the reflectance is improved by increasing the number of the dielectric layers H and L by the method for manufacturing the semiconductor light emitting element substrate of the present invention, the dielectric layers H and L can be obtained in a short time. And the reflective layer R can be formed into a film.

  Thus, after each dielectric layer H and L is formed in dielectric layer formation process S108, it progresses to substrate heating stop process S109 which stops heating of substrate S. The substrate heating stop step S109 is preferably performed by the temperature control means 24. After stopping the substrate heating, the substrate holding means rotating step S5 and the substrate cleaning step S6 may be performed. It progresses to 2nd judgment process S110. The steps after the second determination step S110 shown in FIG. 5 and the steps after the second determination step S10 in FIG.

  Next, an embodiment of the present invention will be described with reference to FIG. FIG. 6 is a graph showing the relationship between the manufacturing time of the semiconductor light emitting device substrate and the substrate temperature according to the example of the present invention. The structures of the dielectric layers H and L and the reflective layer R of the semiconductor light emitting element substrate of this example are the structures shown in FIG. In addition, the dielectric layers H and L and the reflective layer R of the semiconductor light emitting element substrate of the present embodiment are manufactured using the thin film forming apparatus 1 described with reference to FIG. 1 and the manufacturing process described with reference to FIG. After that, a film was formed.

In this example, the dielectric layers H and L were formed under the following conditions.
Substrate: sapphire substrate high refractive index dielectric material: TiO ₂ (refractive index: 2.52),
Low refractive index dielectric material: SiO ₂ (refractive index: 1.45)
TiO ₂ deposition rate: 0.5 nm / sec
SiO ₂ deposition rate: 1.0 nm / sec
Ion source conditions during evaporation of TiO ₂ / SiO ₂
Introduced gas: Oxygen 60sccm
Ion acceleration voltage: 1200V
Ion current: 1200 mA
Ion beam energy density: 100 mW / cm ²
Neutralizer conditions
Neutralizer current: 2000mA
Discharge gas: Argon 10 sccm

  In FIG. 6, the horizontal axis indicates when the substrate S is heated by the heating means 8 in FIG. This is the manufacturing time with step S3) set to zero. The vertical axis indicates the substrate temperature measured by the thermometer 25. A rapid temperature increase is observed immediately after the start of manufacture, and the substrate temperature is kept constant until about 18 minutes have passed since the start.

  This indicates that the substrate S was heated by the substrate heating step S3 in FIG. 4 during the lapse of 18 minutes from the start of manufacturing. Further, the temperature of the substrate S in the substrate heating step S3 was set to 110 ° C. in order to increase the packing density of the dielectric layers H and L. Further, before the heating of the substrate S is started, the evacuation step S2 of FIG. 4 is performed.

Then, after about 18 minutes have passed since the start (line A in FIG. 6), it was confirmed that the pressure in the vacuum chamber 2 became about 1 × 10 ⁻³ Pa, and therefore the vacuum chamber in the first determination step S4. 4 is determined to be 1 × 10 ⁻³ Pa or less, and then the substrate holding means rotating step S5 and the substrate cleaning step S6 in FIG. 4 are performed before the dielectric layer forming step S7 is performed. Yes.

  In FIG. 6, an increase in the substrate temperature is observed at about 19 minutes because the substrate cleaning step S6 was performed by ion cleaning. After the completion of ion cleaning, a decrease in substrate temperature is observed.

  Thereafter, the substrate temperature is repeatedly increased and decreased until reaching the line B in FIG. 6, which is formed by sequentially forming the dielectric layers H and L in the dielectric layer forming step S7 of FIG. Indicates that In FIG. 6, the first and second layers of the high-refractive index dielectric layer H and the first and second layers of the low-refractive index dielectric layer H are sequentially formed on the substrate S for 20 to 27 minutes. It shows that the film is formed alternately.

  After all the dielectric layers are formed (that is, line B in FIG. 6), cooling is started by the cooling step S9 in FIG. At this time, the substrate heating stop step S8 is also performed almost simultaneously. A gentle decrease in the substrate temperature observed between line B and line C in FIG. 6 indicates that cooling is being performed. More specifically, it shows that cooling is performed from about 27 minutes after the start of production to about 57 minutes (30 minutes, the time indicated by the arrow in FIG. 6).

Thereafter, a slight increase in the substrate temperature is observed around 45 minutes from the start of manufacture (line C in FIG. 6). This is because the Al crucible for depositing the reflective layer R is placed in the electron beam for 1 minute. This is because it was preheated with At this time, the pressure in the vacuum chamber 2 was 5.0 × 10 ⁻⁴ Pa or less.
After that, ion cleaning using an ion beam was performed for 1 minute on the film on which the reflective layer R was laminated. In addition, the pressure in the vacuum chamber 2 at the time of ion cleaning was about 2.1 × 10 ⁻² Pa.

Ion cleaning conditions using an ion beam were performed under the following conditions.
Ion cleaning conditions
Introduced gas: Oxygen 60sccm
Ion acceleration voltage: 500V
Ion current: 500 mA
Neutralizer conditions
Neutralizer current: 1000mA
Discharge gas: Argon 10 sccm

Thereafter (after the line D in FIG. 6), the inside of the vacuum chamber 2 was decompressed while cooling the substrate S until the inside of the vacuum chamber 2 was in an appropriate pressure range for forming the reflective layer R. Then, when 55 minutes have elapsed from the start of manufacture (line E in FIG. 6), the pressure in the vacuum chamber 2 is 3 × 10 ⁻⁴ Pa or less in the second determination step S10 in FIG. It was confirmed that the temperature was 50 ° C. or lower.
At this time, the inside of the vacuum chamber 2 was 2.0 × 10 ⁻⁴ Pa, and the radiation thermometer was 30 ° C.

From 55 to 57 minutes from the start of manufacture (between lines E and F in FIG. 6), the pressure in the vacuum chamber 2 is set to 2.0 to 3.0 × 10 ⁻⁴ Pa, and the substrate An Al film was deposited on S to form a reflective layer R (reflective layer forming step S11).
At this time, since the substrate S was cooled, a large temperature rise was not observed, and the substrate S was almost constant.
Thereafter, the substrate S was further cooled until the temperature of the substrate S became around room temperature, and the vacuum chamber 2 was leaked (leak process S12).

  Therefore, in this example, after the dielectric layer is formed (line B in FIG. 6), the time for cooling the substrate until the start of the formation of the reflective layer R (line E in FIG. 6) is 28 For minutes. In the conventional method, in order to form the reflective layer R, the substrate temperature is cooled to 50 ° C. or lower, and the cooling time is about 2 to 3 hours. On the other hand, in this example, the substrate temperature could be cooled to a lower room temperature, and the cooling time could be as short as 28 minutes.

The reflective layer R was formed under the following conditions.
Reflective layer material: Al
Al film formation rate: 2.5 nm / sec

  The reflectance at 450 to 470 nm (the emission wavelength range of the blue LED) of the reflective layer R formed in this example was 98%. Therefore, according to the present invention, the reflective layer R of the semiconductor light emitting element substrate has a good reflectance, and the manufacturing time can be effectively shortened.

Claims (5)

On the substrate, a layer made of any material of titanium oxide, zirconium oxide, tantalum oxide or niobium oxide, and a layer made of any material of aluminum oxide, silicon oxide or magnesium fluoride, Is a method of manufacturing a semiconductor light emitting element substrate comprising a dielectric layer formed by alternately combining and a reflective layer made of aluminum in order on one surface,
A substrate holding step of holding the substrate on a substrate holding means disposed in a vacuum chamber;
An evacuation step of evacuating the vacuum chamber;
A substrate heating step that is performed substantially simultaneously with the evacuation step and heats the substrate;
A substrate cleaning step of irradiating the substrate with ions to clean the substrate;
The temperature of the substrate and 100 to 120 ° C., a dielectric layer forming step of depositing a pre Symbol dielectric layer on the substrate,
A substrate heating stop step for stopping heating of the substrate;
The cooling means disposed near the substrate and not in contact with the substrate absorbs radiant heat from the substrate and the substrate holding means and starts cooling the substrate and the substrate holding means. Cooling process to
A method of manufacturing a semiconductor light-emitting element substrate, comprising: a reflective layer forming step in which the temperature of the substrate is set to 25 to 70 ° C. and the reflective layer is deposited on the dielectric layer in this order. On the substrate, a layer made of any material of titanium oxide, zirconium oxide, tantalum oxide or niobium oxide, and a layer made of any material of aluminum oxide, silicon oxide or magnesium fluoride, Is a method of manufacturing a semiconductor light emitting element substrate comprising a dielectric layer formed by alternately combining and a reflective layer made of aluminum in order on one surface,
A substrate holding step of holding the substrate on a substrate holding means disposed in a vacuum chamber;
An evacuation step of evacuating the vacuum chamber;
A substrate heating step that is performed substantially simultaneously with the evacuation step and heats the substrate;
The cooling means disposed near the substrate and not in contact with the substrate absorbs radiant heat from the substrate and the substrate holding means and starts cooling the substrate and the substrate holding means. Cooling process to
A substrate cleaning step of irradiating the substrate with ions to clean the substrate;
The temperature of the substrate and 100 to 120 ° C., a dielectric layer forming step of depositing a pre Symbol dielectric layer on the substrate,
A substrate heating stop step for stopping heating of the substrate;
A method of manufacturing a semiconductor light-emitting element substrate, comprising: a reflective layer forming step in which the temperature of the substrate is set to 25 to 70 ° C. and the reflective layer is deposited on the dielectric layer in this order. Before the substrate cleaning step, further comprising a first determination step of determining whether the inside of the vacuum chamber is 1 × 10 ⁻³ Pa or less,
3. The method of manufacturing a semiconductor light emitting element substrate according to claim 1, wherein the substrate cleaning step is performed when the inside of the vacuum chamber is 1 × 10 ⁻³ Pa or less. Before the reflective layer forming step, further comprising a second determination step of determining whether the temperature of the substrate is 50 ° C. or lower and the inside of the vacuum chamber is 3 × 10 ⁻⁴ Pa or lower,
4. The semiconductor light emitting element substrate according to claim 3, wherein when the temperature of the substrate is 50 ° C. or less and the inside of the vacuum chamber is 3 × 10 ⁻⁴ Pa or less, the reflective layer forming step is performed. Production method. The second determination step includes a vacuum pump connected to the vacuum chamber via a vacuum valve, a pressure control unit connected to the vacuum valve, a thermometer installed near the substrate, and a cooling unit. Connected temperature control means, and
5. The reflection layer forming step is performed by controlling the shutter control unit connected to the pressure control unit and the temperature control unit to open a shutter disposed on an evaporation source. The manufacturing method of the semiconductor light-emitting device board | substrate as described in 2.

Images