JP3332257B2 - Vacuum processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum processing apparatus, and more particularly to a cold wall type vacuum processing apparatus that heats and processes only a substrate.

[0002]

2. Description of the Related Art A vacuum processing apparatus equipped with a heating mechanism includes:
There are two main types. The first type is a hot wall type vacuum processing apparatus that heats the entire inner wall of the vacuum vessel to a temperature equivalent to the processing substrate, and the second type is a cold wall type vacuum processing apparatus that heats only the processing substrate. . In each device, the target temperature is detected by a temperature measuring element (temperature detector) such as a thermocouple, and precise temperature control is performed by applying a feedback control method using the detection signal.

[0003] The cold wall type vacuum processing apparatus can be reduced in size, consumes a small amount of heat, and when used as a film forming apparatus, produces no product on the inner wall and has good maintainability. Has advantages. On the other hand, a hot wall type vacuum processing apparatus can realize a black body furnace, and completely grasps the temperature of the processing substrate to be heated, regardless of where the temperature measuring element is disposed in the furnace. It has the advantage of being able to.

[0004]

In the cold wall type vacuum processing apparatus, there is a temperature difference between the processing substrate to be heated and the surrounding environment. Since the state of heat radiation (heat emissivity) from the surface varies depending on the surface state (for example, uneven state or material), it has been difficult to accurately measure the temperature of the substrate using a temperature measuring element. For this reason, attempts have been made to measure the temperature of the substrate by bringing the temperature measuring element as close to the substrate as possible, but even so, accurate temperature measurement has not been realized. In addition, due to these inconveniences, there is also a problem that it is extremely difficult to accurately reproduce the temperature of the processing surface of the substrate as intended.

In the conventional cold wall type vacuum processing apparatus, the temperature measuring element is brought close to the processing substrate so that the temperature measured by the temperature measuring element approaches the temperature of the substrate. Only inaccurate environmental temperatures that fluctuate due to In other words, due to its configuration, it has been impossible to detect a temperature that accurately reflects the surface temperature of the processing substrate.

Accordingly, the present inventors solve the need for temperature reproducibility in a substrate by a new concept by comprehensively examining the problem of heat radiation from the substrate side.

Further, unlike the above-mentioned problem of heat radiation from the substrate, there is a conventional technique using a heat reflection plate to solve the problem of heating a substrate having a high heat transmittance (Japanese Patent Laid-Open No. Hei 3 (1993) -209). -253572). This prior document discloses a configuration in which, of the heat applied to a substrate from a heater, heat transmitted through the substrate is returned to the substrate by a heat reflecting plate. This conventional technique realizes efficient heating particularly in heating for raising the temperature of a glass substrate or the like having a high heat transmittance to a desired temperature, that is, in a state where the temperature level is relatively low, and achieves a good temperature rise. Is achieved.

In contrast to the prior art described above, the problem of heat radiation from the substrate according to the present invention is that when the substrate reaches a desired temperature, the temperature of the entire surface of the substrate processing surface is accurately reproduced to the target temperature. To contemplate.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the cold wall type vacuum processing apparatus, an object of the present invention is to maintain the temperature of a processing substrate at a desired constant temperature which does not vary irrespective of the surface condition, and to obtain a desired processing substrate. An object of the present invention is to provide a vacuum processing apparatus capable of realizing precise temperature reproducibility so as to reach a temperature.

[0010]

A vacuum processing apparatus according to the present invention is configured as follows. In the depressurized internal space, only the substrate is heated by a heater arranged on one surface side of the substrate, and the other surface of the substrate is configured to be a processing surface. Same as the board on the side
A radiant heat reflecting member made of material is arranged, the substrate is sandwiched between the heater and the radiant heat reflecting member, and a temperature detector for detecting the temperature of the heater is arranged, based on a detection signal of the temperature detector. A feedback control device for controlling the temperature of the substrate is provided. Here, the radiation heat reflecting member is a member that reflects heat radiated from the substrate side to the substrate side. The radiant heat reflecting member has a function of reflecting radiant heat from the substrate side and returning the radiant heat to the substrate. The form of the radiation heat reflecting member is
Any form can be used as long as it exhibits a desired reflection action. The form of the radiant heat reflecting member is preferably a disk having the same shape as the substrate, and further, with their axes aligned, the reflecting surface of the radiant heat reflecting member and the processing surface of the substrate are substantially parallel to each other. It is desirable to be arranged so that it becomes. It is desirable that the diameter of the radiant heat reflecting member be larger than the diameter of the substrate, but it is not limited to this. The diameter may be equal or smaller. The reflecting surface of the radiation heat reflecting member does not need to be completely flat. It can be concave or convex depending on its purpose or need. Also, regarding the form of the heat reflecting member, it is possible to increase the heat capacity by increasing the mass. This configuration is convenient when utilizing the heat radiation phenomenon of the radiation heat reflecting member itself.

It is preferable that the radiation heat reflecting member is made of a material having high heat radiation reflection efficiency. However, depending on the purpose of the treatment, the material is preferably the same as the material of the substrate. When the substrate is silicon and a silicon (Si) film is formed thereon, the radiation heat reflecting member is also silicon. Regarding the arrangement position of the radiation heat reflecting member, various modifications can be assumed. In this arrangement position, the distance from the substrate is regarded as important. Basically, a position where a pseudo blackbody furnace can be substantially formed on the other surface of the substrate, that is, the space in front of the processing surface based on the heat reflection effect of the radiant heat reflection member is desirable. When a vacuum processing apparatus is used as a film forming apparatus, it is desirable that the source gas be supplied to the other surface of the substrate, that is, a space in front of the processing surface at a pressure that does not cause heat conduction. In addition, utilizing the fact that a blackbody furnace is formed between the substrate and the radiant heat reflecting member, a temperature detector is arranged between the substrate and the radiant heat reflecting member, and based on a detection signal of this temperature detector. It is also possible to provide a feedback control device for controlling the temperature of the substrate.

[0012]

According to the present invention, the space on the processing surface side of the substrate, that is, the space on the opposite side of the substrate from the side where the heater is disposed,
The radiant heat reflecting member is arranged at an appropriate interval, so that the radiant heat reflecting member returns the heat radiation energy from the substrate side to the substrate based on its reflection action. Even if the amount of heat applied to the substrate by the heater is constant, the thermal energy escaping from the processing surface of the substrate changes according to the surface condition of the processing surface. Therefore, when the reflectance of the radiant heat reflecting member is ideally close to 1 and the heat escaping from the substrate is reflected and returned to the substrate again, heat is returned according to the amount of heat energy escaping. As a result, the energy supplied to the substrate can be kept constant even if substrates having different surface states are heated, without depending on the radiation intensity of heat from the substrate surface. In such a state,
When the output of the heater is detected and feedback control is performed to control the output of the heater to a desired amount, the surface temperature of the substrate can be controlled with good reproducibility without depending on the surface state of the substrate. The temperature of the substrate is determined by the power supplied from the heater. In addition, by installing the radiant heat reflecting member, a pseudo black body furnace is formed in the space between the substrate and the radiant heat reflecting member, and by using this environment, the temperature detector and the feedback control device are similarly formed. By providing the substrate, the reproducibility of the substrate temperature can be improved.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a vertical cross-sectional view of the apparatus configuration. This figure schematically shows the size, shape, and arrangement relationship of each component so that the present invention can be understood. FIG. 2 shows a configuration of a control system that performs feedback control. 3 to 8 show various characteristic graphs obtained by the vacuum processing apparatus according to the present invention or the conventional apparatus.

FIG. 1 shows a vacuum processing apparatus for realizing the present invention, which is generally called a UHV-CVD apparatus for performing deposition or epitaxial growth on a heated substrate. The present apparatus can be used as a vacuum annealing apparatus for heating a substrate. The vacuum processing apparatus is a growth chamber for processing a substrate in a reduced-pressure environment state, an exhaust device for setting the growth chamber to a required reduced pressure state, and introducing a substrate to be processed into the growth chamber without exposing the atmosphere. And a carry-in mechanism for introducing a substrate from the substrate exchange chamber to the growth chamber. In FIG.
For convenience of explanation, only the growth chamber and the exhaust device are shown, and the illustration of the substrate exchange chamber and the loading mechanism is omitted. Any conventional apparatus can be used for the substrate exchange chamber and the loading mechanism.

A substrate 1 made of, for example, silicon and carried into a growth chamber with a processing surface facing upward by a transport mechanism.
Is disposed on a substrate support mechanism (not shown). The substrate support mechanism includes a substrate elevating device 2 that moves the substrate up and down. By the substrate lifting device 2, the installation position of the substrate 1 is adjusted to an appropriate position in the growth chamber. The growth chamber has two chambers due to the presence of the substrate 1 arranged on the substrate support mechanism.
That is, the upper chamber 3 and the lower chamber 4 are divided. Upper room 3 is wall 5,
It is a closed space formed by 6 and 7. A gas introduction mechanism (not shown) is attached to the upper chamber 3, and 8 is a gas nozzle thereof. A source gas is supplied from the gas nozzle 8 as needed. The lower chamber 4 is also a closed space, and a substrate heating mechanism is disposed in the lower chamber 4. 9 is a heater included in the substrate heating mechanism, and 10 is a heat reflecting plate included in the substrate heating mechanism. In FIG. 1, the illustration of a power supply for supplying electric power to the heater 9 is omitted. As a device used for the heater 9, for example, a carbon heater or the like is used,
Other arbitrary ones can be used. Each wall material forming the chamber wall is not clearly shown, but strictly has a cavity formed therein, and the cavity is configured to circulate cooling water. A cold wall is formed by this structure, and in this vacuum processing apparatus, only the substrate 1 is heated by the heater 9. The heater 9 is arranged on the lower surface side of the substrate 1 in FIG. 1, radiates heat when energized by a power supply, and applies radiant heat to the substrate 1 from the lower surface side of the substrate 1 to heat it.

Reference numerals 11 and 12 denote turbo molecular pumps each having a large pumping speed, and are included in a pumping mechanism. According to the turbo molecular pumps 11 and 12, each of the upper chamber 3 and the lower chamber 4 can be evacuated to a maximum pressure of 10 ⁻¹⁰ Torr. Further, when the source gas is introduced from the gas nozzle 8, the internal pressure of the upper chamber 3 can be maintained in a molecular flow region of about 10 ^-4 Torr. According to the internal pressure of the molecular flow region, the source gas can be supplied to the space in front of the processing surface of the substrate 1 at a pressure that does not cause heat conduction.

Reference numeral 13 denotes a radiation heat reflecting member. The radiant heat reflecting member 13 is disposed in a space on the processing surface side of the substrate 1, that is, in the upper chamber 3 above the substrate. The radiant heat reflecting member 13 is arranged in the upper chamber 3 while being fixed by the support member 14. The radiant heat reflecting member 13 raises the temperature of the substrate 1 by heating by the heater 9, and the radiant heat reflecting member 13
Has the function of reflecting the heat radiated on the side of the substrate 1 on its reflection surface and returning it to the processing surface side of the substrate 1. It is also conceivable that the radiant heat reflecting member 13 receives the radiant heat from the substrate 1 and the temperature thereof rises. As a result, the radiant heat from the radiant heat reflecting member 13 is returned to the substrate 1. The reflection surface 13 a of the radiant heat reflection member 13 is a surface facing the processing surface (upper surface) of the substrate 1. In this embodiment, the radiant heat reflecting member 13 is arranged in a fixed state so that the reflecting surface 13a is substantially parallel to the processing surface of the substrate 1. In this embodiment, the reflection surface of the radiation heat reflection member 13 is a mirror-polished plane. However, the reflecting surface is not limited to a perfect plane. For example, the reflecting surface of the radiant heat reflecting member 13 can be formed to be concave or convex depending on the purpose or as necessary. When the distance between the member to be heated and the reflection member is large, a concave surface can be used to increase the reflection efficiency, and the concave surface can be formed for the purpose of returning heat to the substrate 1 by concentrating heat at an arbitrary location. On the other hand, in the case of a convex surface, heat can be dispersed and returned to the substrate 1.

The radiant heat reflecting member 13 is desirably plate-shaped as shown in FIG. The planar shape is desirably the same circle as the substrate 1. Further, the material of the radiation heat reflecting member 13 is preferably the same as that of the substrate 1, and in this embodiment, silicon is used. The disk-shaped radiant heat reflecting member 13 is arranged such that the central axis thereof coincides with the central axis of the substrate 1. The radial dimension of the radiant heat reflecting member 13 is preferably larger than the diameter of the substrate 1. This is because the amount of heat that can be reflected increases and the escape of heat decreases. However, it is not particularly limited. In the case of the present embodiment, as an example, a 6-inch substrate is used as the substrate 1 and a radiant heat reflecting member 13 having a size corresponding to an 8-inch substrate is used. Further, the shape of the radiant heat reflecting member 13 is not limited to a plate shape. For example, when a large capacity for storing heat is required, the thickness, the mass, and the like can be increased. Therefore, any shape can be adopted as long as the condition of the reflecting surface can be satisfied. Further, the shape of the reflection surface can be further modified. For example, the reflection surface may be formed as a concave portion, and the shape may be such that the peripheral surface of the substrate 1 is surrounded by the shape. According to this, the reflection efficiency of radiant heat can be further increased.

In FIG. 1, reference numeral 15 denotes a thermocouple which is an example of a temperature measuring element. In the vacuum processing apparatus according to the present embodiment, the thermocouple 15 is configured to detect the temperature of the heater 9, that is, the output of the thermocouple 9 as close as possible to the heater 9. The temperature signal detected by the thermocouple 15 is sent to the control device 16 as shown in FIG. The control device 16 adjusts the output power of the power supply 17 in order to maintain the heater 9 at a predetermined desired output. By providing the feedback control system in this manner, the output generated by the heater 9 is set and maintained at a desired output. By accurately controlling the amount of heat supplied from the heater 9 to the substrate 1 to a desired amount, the temperature of the substrate 1 is increased in combination with the reflection of the radiant heat reflecting member 13 as described later. Can be maintained at a desired temperature with good reproducibility.

Next, the operation of the vacuum processing apparatus having the above configuration and the characteristics of the vacuum processing apparatus based on the operation will be described.

First, in order to clarify the difference between the vacuum processing apparatus according to the present invention and the conventional vacuum processing apparatus, technical limitations of the conventional cold wall vacuum processing apparatus will be described. With a cold-wall type vacuum processing apparatus, it has not been possible to directly measure the surface temperature of a substrate. Therefore, conventionally, attempts have been made to install the thermocouple as close to the substrate as possible, or to measure the surface temperature using a pyrometer. However, as shown in FIG. 3, the measured values of the thermocouple and the pyrometer greatly differed depending on the surface condition of the substrate. This is because the emissivity greatly changes depending on the surface state of the substrate. Fig. 3 shows a two-wavelength pyrometer (1.1 µm and 1.4 µm) against the temperature of the W / Re thermocouple.
FIG. 5 is a diagram showing a relationship between measured temperatures. FIG. 3 shows characteristic graphs for four types of substrates, in which the first to third substrates have a thin film pattern of SiO ₂ , and the black circle characteristic graph has a pattern with a thickness of 800 Å.
A black square characteristic graph has a pattern with a thickness of 1500 angstroms, a black triangle characteristic graph has a pattern with a thickness of 2000 angstroms, and a white circle is a characteristic graph of a fourth silicon substrate without a thin film pattern. This is the same in the characteristic graphs of the other figures. Attempts have been made to measure the radiation temperature at two different wavelengths and cancel the emissivity in the pyrometer temperature measurement method. However, since the emissivity differs depending on the surface temperature and wavelength,
A temperature measurement method that completely eliminates the effect of emissivity has not been established. Also, unless a thermocouple is embedded in the substrate or arranged at a position where it comes into contact with the substrate, the radiation of the wavelength felt by the thermocouple is measured, and it depends on the emissivity. In addition, contacting or embedding a metal thermocouple with the substrate changes the properties of silicon as a material, and is practically impossible. Therefore, conventionally, there is no means for completely measuring the surface temperature of the silicon substrate, and this is the same situation even at present.

In the vacuum processing apparatus according to the present invention having the above-described configuration, the idea of completely and accurately measuring the surface temperature of the substrate 1 is not adopted. The desire to completely and accurately measure the surface temperature of a substrate requires the temperature of the processed surface of the substrate to be
This is to achieve the purpose of accurately maintaining a desired constant temperature. Therefore, the configuration of the present invention basically realizes temperature reproducibility such that the final substrate temperature state is accurately maintained at a desired temperature state without completely measuring the substrate surface temperature.

In the vacuum processing apparatus of the present embodiment shown in FIG. 1, a radiant heat reflecting member 13 is arranged on the processing surface side of the substrate 1 at a position away from the substrate 1 by a predetermined distance, and the reflecting surface of the substrate 1 It faces the processing surface. When the temperature of the substrate 1 is increased by the heater 9, thermal radiation is generated from the processing surface of the substrate 1 at an emissivity determined by the surface condition. When heat radiation is generated from the processing surface of the substrate 1, the reflection surface of the radiant heat reflecting member 13 emits heat to the substrate 1 side with the same reflectance at any point according to the radiant heat given from the substrate 1 with a reflectance of about 1. reflect. Since the reflection surface of the radiant heat reflection member 13 is formed of silicon at any point and there is no difference in surface state, it is considered that the reflectance is constant. Therefore, heat corresponding to the radiant heat is returned to the substrate 1, so that a temperature that does not depend on the surface state of the substrate 1 is finally realized. As a result, the substrate 1
Is determined only by the output (heat amount) supplied from the heater 9, and therefore does not depend on the surface state of the substrate 1.

The temperature of the radiant heat reflecting member 13 itself rises due to the radiant heat from the substrate 1, but it is considered that the radiant heat is returned to the substrate 1 mostly by the reflection action on the reflection surface. According to the above-mentioned reflection action of the radiant heat reflecting member 13, it is considered that a black body furnace is formed in a space between the substrate 1 and the radiant heat reflecting member 13.
The specific numerical value of the distance between the radiant heat reflecting member 13 and the substrate 1 is appropriately determined according to various conditions such as the size of the substrate 1 and the radiant heat reflecting member 13, but a pseudo blackbody furnace is formed. Is a major factor in the condition.

FIG. 4 is a characteristic graph showing the thermocouple temperature dependence of the growth rate of the thin film on the substrate when the radiation heat reflecting member 13 is not present. That is, in the vacuum processing apparatus of FIG. 1, the substrate 1 heated by the heater 9 to which the feedback control system by the thermocouple arranged to measure the temperature of the substrate is applied without installing the radiant heat reflecting member 13 is applied. The source gas Si ₂ H ₆ is supplied from the nozzle 8 onto the processing surface, and the substrate temperature dependence of the growth rate when selective epitaxial growth is performed is examined. Epitaxial growth was performed under growth conditions that did not depend on the flow rate of the source gas, but only on the temperature of the substrate. As described in FIG. 4, three kinds of substrates having different surface states were prepared. The growth rate was determined by performing selective growth on the patterned oxide film, measuring the epitaxial film thickness after removing the oxide film by the step method, and calculating the growth rate.

It can be seen from the graph of FIG. 4 that the growth rate differs depending on the surface condition of the substrate even at the same thermocouple temperature. This means that the growth rate depends on the surface temperature of the substrate, and furthermore that the thermocouple cannot accurately reflect the surface temperature despite the fact that the surface temperature varies depending on the surface condition of the substrate. Means.

FIG. 5 shows the dependence of the growth rate on the thermocouple temperature in the case of the vacuum processing apparatus of the present invention having the configuration shown in FIG. I have. The radiant heat reflecting member 13 is installed at a distance of about 25 mm from the substrate 1 as an example. However, in this case, the thermocouple 15 and the feedback control system shown in FIG. 2 are not operated, and an appropriate amount of heat is simply given from the heater 9 to the substrate 1. Other conditions are the same as those described with reference to FIG. As is clear from the graph of FIG. 5, also in this case, the growth rate differs for each substrate for each thermocouple temperature. The difference from the case of FIG. 4 is that the growth rate has the same tendency as the pyrometer temperature change shown in FIG.

FIG. 6 shows the configuration of the apparatus shown in FIG.
Further, regarding the temperature control system, the output of the heater 9 is detected by measuring the temperature of the heater 9 with the thermocouple 15, and the feedback control is executed by the control device 16 so that the output becomes constant. That is, this is the case of a vacuum processing apparatus that completely implements the configuration shown in FIG. As a result, as is clear from the graph of FIG. 6, the same growth rate can be obtained for different types of substrates for the same output of the heater 9. That is, the same growth rate determined by the output of the heater 9 can be obtained without depending on the surface state of the substrate 1.

FIG. 7 shows that the output of the heater 9 is constant (for example, 8
10 is a graph showing a change in growth rate when the distance between the substrate 1 and the radiant heat reflecting member 13 is changed, for example, in a range of about 30 to 80 mm under control of maintaining the power to 50 W). According to the graph of FIG. 7, the growth rate decreases as the installation position of the radiant heat reflecting member 13 is farther from the substrate 1. This characteristic also occurred in all three types of substrates. Furthermore, when the position where the radiant heat reflecting member 13 is disposed with respect to the substrate 1 exceeds a certain distance, a difference appears in the growth rate depending on the type of the substrate. This means that when the radiant heat reflecting member 13 is installed in a state where the distance from the substrate 1 is included in a certain range, the presence of the radiant heat reflecting member 13 It can be said that the temperature of the substrate 1 is controlled to a constant temperature by properly compensating for the temperature difference due to the difference in the surface state. Therefore, when the radiant heat reflecting member 13 is provided in the vacuum processing apparatus, it is desirable to install the radiant heat reflecting member under a condition that the distance from the substrate is within a certain range. However, the condition regarding the distance between the substrate and the radiant heat reflecting member differs depending on other conditions, such as the size of the substrate and the radiant heat reflecting member, the amount of heat supplied from the heater, and the like, and cannot be numerically limited. ,
In each case, it depends on the design conditions of the vacuum processing apparatus and the like. When the installation position of the radiant heat reflecting member 13 is not included in a certain distance from the substrate 1, strictly speaking, a difference appears in the growth rate depending on the type of the substrate 1 as described above. However, as to whether the difference is effective or negligible, it depends on the situation, so it is not technically meaningful to install a radiant heat reflecting member outside such a range. Cannot be determined. If necessary, a radiant heat reflecting member may be installed and used at a position where the distance from the substrate is outside the certain range.

In a conventional vacuum processing apparatus, a thermocouple as a temperature measuring element has been used as close to the substrate as possible as described above. However, according to the configuration of the vacuum processing apparatus according to the present invention, as shown in FIG. 8, the thermocouple 15 is installed so as to be separated from the substrate 1 and as close to the heater 9 as possible to measure the output of the heater 9. It is considered appropriate to do so. FIG. 8 shows the distance between the substrate and the thermocouple on the horizontal axis, and shows the growth rate and the substrate-thermocouple distance dependency.
When the distance between the substrate and the thermocouple is small, the difference in the growth rate between the different types of substrates is large, and as the distance becomes large, the difference becomes small, and after a certain distance, they substantially coincide. As shown in FIG. 6, in the case of the vacuum processing apparatus of the present invention,
Based on a combination of the radiation heat reflecting member 13 being disposed at a certain suitable distance from the substrate 1 and maintaining the output of the heater 9 at a certain suitable constant state, the surface of the substrate 1 The temperature is reproduced to a desired constant temperature. Therefore, it is desirable that the thermocouple 15 be used close to the heater 9 so as to accurately measure only the output of the heater 9. The reason why the characteristic graph as shown in FIG. 8 is obtained is that the closer the thermocouple 15 is to the heater 9, the less the effect of the temperature change of the substrate 1 on the temperature measured by the thermocouple 15 becomes. This is because it is considered that the control is completely executed.

In the vacuum processing apparatus of the present invention shown in FIG. 1, the following features can be grasped from other viewpoints in terms of structure and operation. That is, the radiant heat reflecting member 1 is located at an optimum position on the opposite side of the substrate 1 from the position where the heater 9 is installed.
As described above, it is supposed that a pseudo blackbody furnace is formed in the space between the processing surface of the substrate 1 and the reflection surface of the radiant heat reflection member 13 by installing 3. Assuming the characteristics of such a black body furnace, the temperature of the substrate 1 can be set to a considerably high degree of accuracy by installing the temperature measuring element in the space between the substrate 1 and the radiant heat reflecting member 13 even if the temperature of the substrate 1 is simulated. It becomes possible to measure with.

When the vacuum processing apparatus according to the present invention is understood from the above viewpoint, the arrangement position of the thermocouple 15 can be changed as follows. That is, instead of installing the thermocouple 15 in the vicinity of the heater 9, the thermocouple 15 is installed in the space between the substrate 1 and the radiation heat reflecting member 13, and a feedback control system similar to that described above is provided. Can also. In this feedback control system, feedback control is directly performed so that the temperature of the substrate becomes a desired temperature.

The vacuum processing apparatus according to the present invention has the following features in configuration and operation from still another viewpoint. A cooling device is added to the radiant heat reflecting member 13 so that the temperature of the radiant heat reflecting member 13 can be kept ideally and completely cooled. In a cold wall type vacuum processing apparatus equipped with such a radiant heat reflecting member, when using a compound gas as a reaction gas and performing gas source epitaxy by a thermal decomposition reaction, a difference in the adhesion coefficient of source molecules due to a difference in film quality on the surface is utilized. To perform selective growth.

In such selective growth utilizing a surface reaction,
In general, it is important to supply the source molecules onto the substrate as raw as possible, that is, without decomposing the source molecules as much as possible in the process of flying the source molecules onto the substrate. When the source molecules are decomposed in the middle, molecules having a large adhesion coefficient are formed, so that selective growth becomes almost impossible. For this reason, in a system in which a decomposition reaction occurs in a gas phase such as plasma CVD or atmospheric pressure CVD, or in a system in which a decomposition reaction occurs on a hot wall such as a hot-wall type low-pressure CVD apparatus, selective growth is impossible. Was. In particular, in a hot-wall type CVD apparatus, an environment close to an ideal blackbody furnace can be realized in terms of temperature control, but selective growth using a surface reaction cannot be performed. On the other hand, from the viewpoint of selective growth, a cold wall type CVD apparatus is ideal,
As described above, the conventional apparatus has a drawback in the reproducibility of the substrate temperature. Thus, heretofore, there has been a fact that the blackbody furnace and the selective growth utilizing the surface reaction cannot be simultaneously realized. However, as described above, in the cold wall type vacuum processing apparatus according to the present invention, by providing a completely cooled radiant heat reflecting member, the temperature of the radiant heat reflecting member is set to a sufficiently low temperature as compared with the substrate, and The above-mentioned decomposition of the source molecules can be eliminated, and therefore, selective growth and substrate temperature reproducibility can be realized at the same time.

[0035]

As is apparent from the above description, according to the present invention, in the cold wall type vacuum processing apparatus, the radiant heat reflecting member is installed at the position opposite to the heater with the substrate at the center, and the heating is performed. A feedback control device that controls the output of the vessel to the desired output is provided, so that the temperature of the substrate is uniformly controlled to a desired constant temperature with good reproducibility without being affected by the difference in the surface condition of the substrate to be processed. can do. By disposing a thermocouple in the space between the substrate and the radiant heat reflecting member and providing a similar feedback control device, the temperature reproducibility of the substrate can be similarly realized.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a structure of a vacuum processing apparatus according to the present invention.

FIG. 2 is a block diagram illustrating a configuration of a feedback control system.

FIG. 3 is a graph showing a relationship between a thermocouple temperature and a pyrometer temperature.

FIG. 4 is a graph showing a thermocouple temperature dependence of a film growth rate when a radiation heat reflecting member is not present.

FIG. 5 is a graph showing a thermocouple temperature dependence of a film growth rate when a radiation heat reflecting member is present.

FIG. 6 is a graph showing a heater output dependency of a film growth rate when a radiation heat reflecting member is present.

FIG. 7 is a graph showing the dependence of the film growth rate on the distance between the substrate and the radiation heat reflection member when the radiation heat reflection member is present.

FIG. 8 is a graph showing the dependence of the film growth rate on the distance between the substrate and the thermocouple when the radiation heat reflecting member is present and under a constant heater output.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Substrate raising / lowering apparatus 3 ... Upper chamber 4 ... Lower chamber 5, 6, 7 ... Wall 8 ... Gas nozzle 9 ... Heater 11, 12 ... Turbo molecular pump 13 ... Radiation heat reflection member 15 ... Thermocouple (temperature measuring element) Or temperature detector) 16 ... control device 17 ... power supply

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Junro Sakai 5-8-1, Yotsuya, Fuchu-shi, Tokyo Nippon Electric Anelva Co., Ltd. Examiner Naoyuki Miyazawa (56) References JP-A-63-259081 (JP, A) JP-A 64-81231 (JP, A) JP-A-3-255620 (JP, A) JP-A 61-9835 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23C 14/00-16/56 H01L 21/205-21/26

Claims (5)

(57) [Claims] In a vacuum processing apparatus for heating only a substrate in a depressurized internal space with a heater disposed on one surface side of the substrate and processing the other surface of the substrate, A radiant heat reflection member made of the same material as the substrate is installed on the other surface side, and a temperature detector for detecting the temperature of the heater is arranged, and a detection signal of the temperature detector is provided. A vacuum control device for controlling the temperature of the substrate based on the feedback control device. (2) In the depressurized internal space, only the substrate is
Heated by a heater arranged on one side of the substrate,
In a vacuum processing apparatus for processing the other surface of the substrate,
When a radiant heat reflecting member is installed on the other side of the substrate,
A temperature detector between the substrate and the radiant heat reflecting member;
Is disposed, and based on the detection signal of the temperature detector, the substrate
A vacuum control device provided with a feedback control device for controlling the temperature of the vacuum processing device. 3. A vacuum processing apparatus according to claim 1, wherein
In this case, the reflection surface of the radiant heat reflection member is in front of the substrate.
A vacuum processing apparatus, which is substantially parallel to the other surface . 4. A vacuum processing apparatus according to claim 1, wherein
The installation position of the radiant heat reflecting member depends on its heat reflection.
Simulates the front space of the other side of the substrate based on the action
A vacuum processing apparatus at a position where a black body furnace is formed . 5. A vacuum processing apparatus according to claim 1, wherein
Pressure at which the source gas does not conduct heat.
The vacuum processing apparatus is supplied to a front space of the other surface of the substrate .