JP2013037978A - Plasma processing device and plasma processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma processing device and method capable of processing an entire desired processed region of a substrate in a short time when a portion near a surface of the substrate is uniformly heat-treated at a high temperature only in a short time, or when plasma of reaction gas or plasma and a reaction gas flow are radiated on the substrate at the same time to plasma-treat the substrate at a low temperature.SOLUTION: In an inductive coupling type plasma torch unit T, a solenoid coil 3 and a quartz tube 15 are jointed to a quartz block 4. The quartz block 4 is cooled by water flowing in the solenoid coil 3 and a quartz tube 15. A plasma jet port 8 is provided at a lowest part of the inductive coupling type plasma torch unit T. While gas is supplied to a space 7 inside a long chamber, high frequency power is supplied to the solenoid coil 3, so as to generate plasma in the space 7 inside the long chamber and radiate it to a substrate 2.

Description

  The present invention includes a thermal plasma process for treating a substrate by irradiating the substrate with thermal plasma, a low-temperature plasma process for treating a substrate by simultaneously irradiating the substrate with plasma by a reactive gas or plasma and a reactive gas flow The present invention relates to a plasma processing apparatus and a plasma processing method.

  Conventionally, semiconductor thin films such as polycrystalline silicon (poly-Si) are widely used for thin film transistors (TFTs) and solar cells. In particular, the poly-Si TFT has a high carrier mobility and can be manufactured on a transparent insulating substrate such as a glass substrate. For example, a pixel circuit such as a liquid crystal display device, a liquid crystal projector, or an organic EL display device can be used. It is widely used as a switching element constituting the circuit or as a circuit element of a liquid crystal driving driver.

  As a method for manufacturing a high-performance TFT on a glass substrate, there is a manufacturing method generally called “high temperature process”. Among TFT manufacturing processes, a process using a high temperature with a maximum temperature of about 1000 ° C. is generally called a “high temperature process”. Features of the high-temperature process are that a relatively good quality polycrystalline silicon can be formed by solid phase growth of silicon, a good quality gate insulating layer can be obtained by thermal oxidation of silicon, and a clean polycrystalline. This is the point that an interface between silicon and the gate insulating layer can be formed. Due to these characteristics, a high-performance TFT having high mobility and high reliability can be stably manufactured in a high-temperature process.

  On the other hand, since the high temperature process is a process of crystallizing a silicon film by solid phase growth, a long-time heat treatment of about 48 hours is required at a temperature of about 600 ° C. This is a very long process, and in order to increase the process throughput, a large number of heat treatment furnaces are inevitably required, and it is difficult to reduce the cost. In addition, quartz glass has to be used as an insulating substrate with high heat resistance, so the cost of the substrate is high and it is said that it is not suitable for large area.

  On the other hand, a technique for lowering the maximum temperature in the process and manufacturing a poly-Si TFT on an inexpensive large-area glass substrate is a technique called “low temperature process”. Among TFT manufacturing processes, a process for manufacturing poly-Si TFTs on a heat-resistant glass substrate that is relatively inexpensive in a temperature environment where the maximum temperature is approximately 600 ° C. or lower is generally called a “low-temperature process”. In a low temperature process, a laser crystallization technique for crystallizing a silicon film using a pulse laser having an extremely short oscillation time is widely used. Laser crystallization is a technique that utilizes the property of crystallizing in the process of solidifying instantaneously by irradiating a silicon thin film on a substrate with high-power pulsed laser light.

  However, this laser crystallization technique has some major problems. One is a large amount of trap levels localized inside the polysilicon film formed by the laser crystallization technique. Due to the presence of the trap level, carriers that are supposed to move in the active layer by the application of voltage are trapped and cannot contribute to electrical conduction, which has adverse effects such as a decrease in TFT mobility and an increase in threshold voltage. Further, there is a problem that the size of the glass substrate is limited due to the limitation of the laser output. In order to improve the throughput of the laser crystallization process, it is necessary to increase the area that can be crystallized at one time. However, since the current laser output is limited, when this crystallization technique is adopted for a large substrate such as the seventh generation (1800 mm × 2100 mm), it takes a long time to crystallize one substrate.

  Laser crystallization technology generally uses a laser shaped in a line, and crystallization is performed by scanning this laser. This line beam is shorter than the width of the substrate because of limited laser output, and it is necessary to scan the laser several times in order to crystallize the entire surface of the substrate. As a result, a line beam seam area is generated in the substrate, and an area that is scanned twice is formed. This region is significantly different in crystallinity from the region crystallized by one scan. For this reason, the element characteristics of the two are greatly different, which causes a large variation in devices. Finally, since the laser crystallization apparatus has a complicated apparatus configuration and a high cost of consumable parts, there are problems that the apparatus cost and running cost are high. As a result, a TFT using a polysilicon film crystallized by a laser crystallization apparatus becomes an element with a high manufacturing cost.

  In order to overcome the problems such as the limitation of the substrate size and the high apparatus cost, a crystallization technique called “thermal plasma jet crystallization method” has been studied (for example, see Non-Patent Document 1). The technology is briefly described below. When a tungsten (W) cathode and a water-cooled copper (Cu) anode are opposed to each other and a DC voltage is applied, an arc discharge occurs between the two electrodes. By flowing argon gas between these electrodes under atmospheric pressure, thermal plasma is ejected from the ejection holes vacated in the copper anode. Thermal plasma is thermal equilibrium plasma, which is an ultra-high temperature heat source having substantially the same temperature of ions, electrons, neutral atoms, etc., and the temperature of which is about 10,000K. Therefore, the thermal plasma can easily heat the object to be heated to a high temperature, and the substrate on which the a-Si film is deposited scans the front surface of the ultra-high temperature thermal plasma at a high speed, thereby crystallizing the a-Si film. Can be

  Thus, since the apparatus configuration is very simple and the crystallization process is performed under atmospheric pressure, it is not necessary to cover the apparatus with an expensive member such as a chamber, and the apparatus cost can be expected to be extremely low. The utilities required for crystallization are argon gas, electric power, and cooling water, which is a crystallization technique with low running costs.

  FIG. 12 is a schematic diagram for explaining a semiconductor film crystallization method using this thermal plasma.

  In FIG. 1, a thermal plasma generator 31 includes a cathode 32 and an anode 33 that is disposed to face the cathode 32 with a predetermined distance therebetween. The cathode 32 is made of a conductor such as tungsten. The anode 33 is made of a conductor such as copper, for example. Further, the anode 33 is formed in a hollow shape, and is configured to be cooled through water through the hollow portion. The anode 33 is provided with an ejection hole (nozzle) 34. When a direct current (DC) voltage is applied between the cathode 32 and the anode 33, an arc discharge is generated between the two electrodes. In this state, by flowing a gas such as argon gas between the cathode 32 and the anode 33 under atmospheric pressure, the thermal plasma 35 can be ejected from the ejection hole 34. Here, the “thermal plasma” is a thermal equilibrium plasma, which is an ultra-high temperature heat source having substantially the same temperature of ions, electrons, neutral atoms, etc., and having a temperature of about 10,000K.

  Such thermal plasma can be used for heat treatment for crystallization of a semiconductor film. Specifically, a semiconductor film 37 (for example, an amorphous silicon film) is formed on the substrate 36, and thermal plasma (thermal plasma jet) 35 is applied to the semiconductor film 37. At this time, the thermal plasma 35 is applied to the semiconductor film 37 while relatively moving along a first axis (left and right direction in the illustrated example) parallel to the surface of the semiconductor film 37. That is, the thermal plasma 35 is applied to the semiconductor film 37 while scanning in the first axis direction. Here, “relatively move” refers to relatively moving the semiconductor film 37 (and the substrate 36 supporting the semiconductor film 37) and the thermal plasma 35, and moving only one or both of them. Any of the cases are included. By such scanning of the thermal plasma 35, the semiconductor film 37 is heated by the high temperature of the thermal plasma 35 to obtain a crystallized semiconductor film 38 (polysilicon film in this example) (for example, see Patent Document 1). ).

  FIG. 13 is a conceptual diagram showing the relationship between the depth from the outermost surface and the temperature. As shown in FIG. 13, only the vicinity of the surface can be processed at a high temperature by moving the thermal plasma 35 at a high speed. After the thermal plasma 35 passes, the heated region is quickly cooled, so that the vicinity of the surface becomes high temperature for a very short time.

  Such a thermal plasma is generally generated in a dotted region. The thermal plasma is maintained by thermionic emission from the cathode 32, and thermionic emission becomes more active at a position where the plasma density is high. Therefore, positive feedback is applied, and the plasma density becomes higher. That is, arc discharge is concentrated on one point of the cathode, and thermal plasma is generated in a dotted region.

  If you want to process a flat substrate uniformly, such as when crystallizing a semiconductor film, it is necessary to scan a dotted thermal plasma over the entire substrate. In order to construct a process that can be processed, it is effective to widen the thermal plasma irradiation area. For this reason, techniques for generating thermal plasma over a large area have been studied for a long time.

  For example, a method for widening a plasma jet by simultaneously jetting a widening gas for widening the plasma jet from two locations in a direction intersecting the central axis of the outer nozzle onto a plasma jet ejected from the outer nozzle of the plasma torch Is disclosed (for example, see Patent Document 2). Alternatively, a plasma nozzle characterized in that the mouth of the nozzle passage is inclined at a predetermined angle with respect to the axis of the nozzle passage, and a casing constituting the nozzle passage, or a part of the casing, A method is disclosed in which a plasma nozzle is passed and moved along a workpiece by rotating it around the longitudinal axis at high speed (see, for example, Patent Document 3). Further, there is disclosed one provided with a rotating head having at least one eccentrically arranged plasma nozzle (see, for example, Patent Document 4).

  It is not intended to process a large area in a short time, but as a welding method using thermal plasma, a strip electrode is used and the width direction is arranged to be the weld line direction and welding is performed. A high-speed gas shielded arc welding method is disclosed (see, for example, Patent Document 5).

  In addition, an inductively coupled plasma torch having a linear elongated shape using a flat rectangular parallelepiped insulator material is disclosed (for example, see Patent Document 6).

  In addition, a method of generating a long and narrow linear plasma using a long electrode has been disclosed (for example, see Patent Document 7). Although described as generating heat plasma, it generates low-temperature plasma and is not suitable for heat treatment. If thermal plasma is generated, it is assumed that it is difficult to generate uniform thermal plasma in the longitudinal direction because arc discharge is concentrated in one place because of the capacitive coupling type using electrodes. On the other hand, the low temperature plasma processing apparatus is an apparatus capable of performing plasma processing such as etching and film formation by converting an etching gas or a gas for CVD (Chemical Vapor Deposition) into plasma.

  Further, a method for generating a long plasma using a microstrip line is disclosed (for example, see Patent Document 8). In this configuration, it is considered that the chamber wall surface in contact with the plasma cannot be completely cooled (not surrounded by the water-cooled flow path), and therefore cannot operate as a thermal plasma source.

  Moreover, what forms a linear elongate plasma torch by arranging a plurality of discharge electrodes in a line is disclosed (see, for example, Patent Document 9).

JP 2008-53634 A Japanese Patent Laid-Open No. 08-118027 JP 2001-68298 A Special Table 2002-500818 Japanese Patent Laid-Open No. 04-284974 Special table 2009-545165 gazette JP 2007-287454 A Special table 2010-539336 JP 2009-158251 A

S. Higashi, H .; Kaku, T .; Okada, H .; Murakami and S.M. Miyazaki, Jpn. J. et al. Appl. Phys. 45, 5B (2006) pp. 4313-4320

  However, conventional techniques for generating a large area of thermal plasma have not been effective for applications in which the vicinity of the surface of a substrate is treated at a high temperature for a very short time, such as crystallization of a semiconductor.

  In the technology for generating thermal plasma in a large area described in Patent Document 2 shown in the conventional example, although the width is widened, the temperature distribution in the widened region is 100 ° C. or more and is uniform. Realization of heat treatment is impossible.

  Further, in the techniques described in Patent Documents 3 and 4 shown in the conventional example, the thermal plasma is generated in a large area, and the heat plasma is essentially oscillated. Since the time is shorter than when scanning without rotating, the time for processing a large area is not particularly shortened. Further, for uniform processing, it is necessary to make the rotation speed sufficiently higher than the scanning speed, and it is inevitable that the nozzle configuration becomes complicated.

  Moreover, the technique described in Patent Document 5 shown in the conventional example is a welding technique and is not a configuration for uniformly processing a large area. Even if this is applied to a large area processing application, in this configuration, since a point-like arc vibrates along the strip electrode, plasma is generated uniformly when time averaged, but instantaneously non-uniform plasma is generated. Has occurred. Therefore, it cannot be applied to large area uniform processing.

  Further, the technique described in Patent Document 6 shown in the conventional example is an inductively coupled high-frequency plasma torch, unlike the technique using DC arc discharge disclosed in Non-Patent Document 1 and Patent Document 1. It is a feature. Since it is an electrodeless discharge, it has the advantages of excellent thermal plasma stability (small time change) and less contamination (contamination) of electrode material into the substrate.

  In an inductively coupled plasma torch, in order to protect the insulator material from high-temperature plasma, a method is generally adopted in which the insulator material is made into a double tube configuration and a coolant is passed therebetween. However, in the technique described in Patent Document 6 shown in the conventional example, since the insulator material has a flat rectangular parallelepiped shape, a refrigerant having a sufficient flow rate can be obtained simply by adopting a double tube configuration. Can't flow. This is because the insulator material is generally inferior in mechanical strength to metal, and if the insulator material is too long in the longitudinal direction, the internal pressure of the double pipe cannot be increased. For this reason, there is a limit to uniformly processing a large area.

  Even if it is assumed that there is no problem of cooling of the insulator material, in the technique described in Patent Document 6 shown in the conventional example, the high-temperature plasma formed in the internal space of the insulator material is from the lowermost part. Since only a small part of the jetting is directly applied to the base material, there is a problem that power efficiency is poor. Further, in the internal space of the insulator material, since the plasma density near the center is high, there is a problem that the plasma becomes non-uniform in the longitudinal direction and the substrate cannot be processed uniformly.

  Even in the case of dot-like thermal plasma, if the diameter is large, the number of scans during large area processing can be reduced, so that it can be processed in a short time depending on the application. However, if the diameter of the thermal plasma is large, the time for the thermal plasma to pass over the substrate during scanning becomes substantially longer, so that only the vicinity of the surface of the substrate cannot be treated at a high temperature for a very short time. Even a considerably deep region of the material becomes high temperature, which may cause defects such as cracking of the glass substrate and peeling of the film.

  Further, the technique described in Patent Document 9 shown in the conventional example is inferior in thermal plasma stability (large time change) as compared to the inductively coupled high-frequency plasma torch described above, and is based on the electrode material. There is a disadvantage that there is a lot of contamination (contamination) in the material.

  The present invention has been made in view of such a problem. When the high temperature heat treatment is performed uniformly over the surface of the base material for a very short time, or the plasma by the reactive gas or the plasma and the reactive gas flow are simultaneously irradiated onto the base material. Thus, it is an object of the present invention to provide a plasma processing apparatus and a plasma processing method capable of processing the entire desired region of the base material in a short time when the base material is subjected to low temperature plasma processing.

  The plasma processing apparatus according to the first invention of the present application is a long chamber provided in a dielectric block, a gas introduction port for supplying gas into the chamber, the dielectric block, and the long block. A dielectric cylindrical tube provided in parallel to the chamber; a long solenoid coil provided in the cylindrical tube; and a high-frequency power source connected to the solenoid coil, wherein the long chamber is long An opening, a substrate mounting table disposed opposite to the opening and holding the substrate, the longitudinal direction of the chamber and the longitudinal direction of the opening being disposed in parallel, and the opening And a moving mechanism that allows the chamber and the substrate mounting table to move relatively in a direction perpendicular to the longitudinal direction.

  With such a configuration, when the high-temperature heat treatment is performed uniformly in the vicinity of the surface of the base material for a very short time, or the base material is subjected to low-temperature plasma processing by irradiating the base material with plasma or plasma and a reactive gas flow at the same time. In this case, the entire desired region to be treated of the substrate can be processed in a short time.

  In the plasma processing apparatus of the first invention of the present application, preferably, the dielectric block is formed by joining two thin plates made of a dielectric having at least one convex portion with the convex portion as a joining surface. It is desirable to be.

  With such a configuration, a plasma processing apparatus can be realized with a simple configuration.

  Further, preferably, the inside of the cylindrical tube is a refrigerant flow path.

  With such a configuration, effective cooling of the plasma processing apparatus can be realized.

  Preferably, a dielectric cylindrical tube serving as a refrigerant flow path is joined to the dielectric block separately from the cylindrical tube provided with the solenoid coil.

  With such a configuration, more effective cooling of the plasma processing apparatus can be realized.

  In this case, it is desirable that the refrigerant flow path communicates with two refrigerant manifolds provided on both sides in the longitudinal direction of the long chamber.

  With such a configuration, more effective cooling of the plasma processing apparatus can be realized.

A plasma processing apparatus according to a second invention of the present application includes a long chamber provided in a dielectric block, a gas introduction port for supplying gas into the chamber, a hollow conductor joined to the dielectric block, and A long solenoid coil made of a tube and provided in parallel to the long chamber, and a high-frequency power source connected to the solenoid coil, the long chamber having a long opening, A substrate mounting table disposed opposite to the opening and holding the substrate;
The longitudinal direction of the chamber and the longitudinal direction of the opening are arranged in parallel, and the chamber and the substrate mounting table are relatively movable in a direction perpendicular to the longitudinal direction of the opening. A moving mechanism is provided.

  With such a configuration, when the high-temperature heat treatment is performed uniformly in the vicinity of the surface of the base material for a very short time, or the base material is subjected to low-temperature plasma processing by irradiating the base material with plasma or plasma and a reactive gas stream simultaneously In this case, the entire desired region to be treated of the substrate can be processed in a short time.

  In the plasma processing apparatus of the second invention of the present application, preferably, the dielectric block is formed by joining two thin plates made of a dielectric having at least one convex portion with the convex portion as a joining surface. It is desirable to be.

  With such a configuration, a plasma processing apparatus can be realized with a simple configuration.

  Further, preferably, the inside of the solenoid coil is a refrigerant flow path.

  With such a configuration, effective cooling of the plasma processing apparatus can be realized.

  In addition, it is preferable that a dielectric cylindrical tube serving as a refrigerant flow path is joined to the dielectric block separately from the solenoid coil.

  With such a configuration, more effective cooling of the plasma processing apparatus can be realized.

  In this case, it is desirable that the refrigerant flow path communicates with two refrigerant manifolds provided on both sides in the longitudinal direction of the long chamber.

  With such a configuration, more effective cooling of the plasma processing apparatus can be realized.

  In the plasma processing method of the third invention of the present application, gas is supplied from a slit-shaped opening formed in the long chamber toward the substrate while supplying the gas into the long chamber surrounded by the dielectric block. In the plasma processing method for generating a high-frequency electromagnetic field in the long chamber by supplying high-frequency power to the coil while ejecting, the chamber and the base material in a direction perpendicular to the longitudinal direction of the opening A plasma processing method for treating the surface of the base material while relatively moving the coil, wherein the coil is composed of a solenoid coil provided in a dielectric cylindrical tube joined to the dielectric block. It is characterized by.

  With such a configuration, when the high-temperature heat treatment is performed uniformly in the vicinity of the surface of the base material for a very short time, or the base material is subjected to low-temperature plasma processing by irradiating the base material with plasma or plasma and a reactive gas flow at the same time. In this case, the entire desired region to be treated of the substrate can be processed in a short time.

  In the plasma processing method of the fourth invention of the present application, gas is supplied from a slit-shaped opening formed in the long chamber toward the substrate while supplying the gas into the long chamber surrounded by the dielectric block. In the plasma processing method for generating a high-frequency electromagnetic field in the long chamber by supplying high-frequency power to the coil while ejecting, the chamber and the base material in a direction perpendicular to the longitudinal direction of the opening A plasma processing method for processing the surface of the base material while relatively moving the coil, wherein the coil is joined to the dielectric block, made of a hollow conductor tube, and the long chamber. It consists of an elongate solenoid coil provided in parallel with the.

  With such a configuration, when the high-temperature heat treatment is performed uniformly in the vicinity of the surface of the base material for a very short time, or the base material is subjected to low-temperature plasma processing by irradiating the base material with plasma or plasma and a reactive gas stream simultaneously In this case, the entire desired region to be treated of the substrate can be processed in a short time.

  According to the present invention, when a high temperature heat treatment is performed uniformly in the vicinity of the surface of the base material for a very short time, or the base material is subjected to low temperature plasma processing by simultaneously irradiating the base material with plasma or plasma and a reactive gas flow. In this case, the entire desired region to be treated of the substrate can be processed in a short time.

Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 1 of this invention The perspective view which shows the structure of the plasma processing apparatus in Embodiment 1 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 2 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 3 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 4 of this invention. The perspective view which shows the structure of the plasma processing apparatus in Embodiment 4 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 5 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 6 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 7 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 8 of this invention. The perspective view which shows the structure of the plasma processing apparatus in Embodiment 8 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in a prior art example Conceptual diagram showing the relationship between the depth from the outermost surface and the temperature in the conventional example

  Hereinafter, a plasma processing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1)
Hereinafter, Embodiment 1 of the present invention will be described with reference to FIG. 1 and FIG.

  FIG. 1A shows the configuration of the plasma processing apparatus according to Embodiment 1 of the present invention, and is a cross-sectional view taken along a plane perpendicular to the longitudinal direction of an inductively coupled plasma torch unit. FIGS. 1B and 1C are cross-sectional views taken along a plane parallel to the longitudinal direction of the inductively coupled plasma torch unit and perpendicular to the substrate. 1B is a cross-sectional view taken along broken lines B to B 'in FIG. 1A, and FIG. 1C is a cross-sectional view taken along broken lines A to A' in FIG. FIG. 1A is a cross-sectional view taken along the broken line in FIG. FIG. 2 is an assembly configuration diagram of the inductively coupled plasma torch unit shown in FIG. 1, in which perspective views of parts (parts) are arranged.

  1 and 2, the base material 2 is placed on the base material placing table 1. In the inductively coupled plasma torch unit T, a solenoid coil 3 as a hollow conductor tube forming a coil is disposed in the vicinity of a quartz block 4 constituting a long chamber made of a dielectric. A brass lid 6 is provided on the quartz block 4. The inductively coupled plasma torch unit T is surrounded by a shield member made of a conductor that is grounded as a whole, and can effectively prevent high-frequency leakage (noise) as well as undesirable abnormal discharge.

  A space 7 inside the long chamber is a slit provided in the quartz block 4. That is, the long chamber is surrounded by the dielectric. The plasma generated in the space 7 inside the long chamber is ejected toward the base material 2 from the plasma ejection port 8 as a slit-like opening in the long chamber. Further, the longitudinal direction of the long chamber and the longitudinal direction of the plasma jet outlet 8 are arranged in parallel.

  A plasma gas manifold 9 is provided above the brass lid 6. The gas supplied to the plasma gas manifold 9 is longer than a plasma gas supply hole 11 as a gas inlet provided in the quartz block 4 via a plasma gas supply pipe 10 formed of a hole provided in the quartz block 4. It is introduced into the space 7 inside the chamber. Since a plurality of plasma gas supply pipes 10 are provided in the longitudinal direction, a uniform gas flow can be easily formed in the longitudinal direction.

  The solenoid coil 3 is joined to the quartz block 4. The central axis of the solenoid coil is arranged in parallel with the longitudinal direction of the long chamber and the longitudinal direction of the plasma jet port 8.

  Further, a shield gas nozzle 13 is disposed in a portion close to the substrate mounting table 1, and a shield gas manifold 14 is provided therein. In this way, two systems of gas introduction are prepared, and a shielding gas is supplied in addition to the plasma gas suitable for plasma generation, such as atmospheric oxygen and carbon dioxide, which are unnecessary or have an adverse effect on processing. It is possible to reduce contamination of the plasma irradiation surface.

  The solenoid coil 3 is hollow, and the inside is a refrigerant flow path. That is, cooling water as a coolant flows inside the solenoid coil 3, and cooling of the solenoid coil 3 and cooling of the quartz block 4 joined thereto are realized. A quartz tube 15 serving as a coolant channel is joined to the dielectric block. All the quartz tubes 15 communicate with a cooling water manifold 18 as a refrigerant manifold formed by a space between a resin case 17 provided outside the brass block 16 and the brass block 16. The resin case 17 is provided with one coolant inlet / outlet as a refrigerant inlet / outlet (not shown), and the water cooling piping to the inductively coupled plasma torch unit T is very simple. And can constitute a small torch. That is, two cooling water manifolds 18 are provided on both sides in the longitudinal direction of the long chamber, and each member is provided with a refrigerant flow path communicating with the two cooling water manifolds 18. The solenoid coil 3 is configured such that the end thereof is bent at a right angle and the refrigerant inlet and outlet do not communicate with the cooling water manifold 18. The solenoid coil 3 may be configured so that the inside of the solenoid coil 3 becomes a coolant channel parallel to the coolant channel to the quartz tube 15.

  The joining of the solenoid coil 3 and the quartz block 4 and the joining of the quartz tube 15 and the quartz block 4 can be performed using various adhesives in addition to the welding method. In order to ensure cooling efficiency, when using an adhesive, it is preferable to apply it as thinly as possible and uniformly.

  The advantage of the structure in which the solenoid coil 3 and the quartz tube 15 are joined to the quartz block 4 is that the existing plate material and tube material can be used, so that it can be manufactured at a low cost and with a short delivery time. Compared to the case of opening, the distance between the long chamber and the refrigerant flow path can be reduced, so that the cooling efficiency is good.

  Both ends of the solenoid coil 3 are connected to a high-frequency matching circuit (not shown) through a copper plate (not shown).

  Thus, in this Embodiment, since the cooling water piping with a circular cross section is closely joined to the quartz block 4, in the technique of the patent document 6 shown in the prior art as a double pipe structure, A much larger amount of refrigerant can be allowed to flow than in the case of water cooling.

  The gas introduction to the plasma gas manifold 9 is realized via a plasma gas supply pipe 21 provided with a flow rate control device such as a mass flow controller upstream thereof.

  A rectangular slit-shaped plasma ejection port 8 is provided, and the substrate mounting table 1 (or the substrate 2 on the substrate mounting table 1) is disposed to face the plasma ejection port 8. In this state, high-frequency power is supplied to the solenoid coil 3 from a high-frequency power source (not shown) while gas is being injected from the plasma outlet 8 toward the base material 2 while supplying gas into the long chamber. The thin film 22 on the substrate 2 can be plasma-treated by generating plasma in the space 7 inside the long chamber and irradiating the substrate 2 with the plasma from the plasma outlet 8. The base material 2 is processed by relatively moving the long chamber and the base material mounting table 1 in a direction perpendicular to the longitudinal direction of the plasma ejection port 8. That is, the inductively coupled plasma torch unit T or the substrate mounting table 1 is moved in the left-right direction in FIG. 1A and in the direction perpendicular to the paper surface in FIGS.

  Various gases can be used as the gas supplied into the long chamber. However, considering the stability of the plasma, the ignitability, the life of the member exposed to the plasma, etc., it is desirable that the main gas is an inert gas. Among these, Ar gas is typically used. When plasma is generated only by Ar, the plasma becomes considerably high temperature (10,000 K or more).

  In this configuration, since the length in the longitudinal direction of the plasma outlet 8 is equal to or larger than the width of the base material 2, a single scan (the inductively coupled plasma torch unit T and the base material mounting table 1 is performed). The entire thin film 22 in the vicinity of the surface of the substrate 2 can be processed by relatively moving).

In such a plasma processing apparatus, a high-frequency power source (not shown) is supplied while Ar or Ar + H ₂ gas is supplied from a gas outlet into a long chamber and gas is jetted from the plasma outlet 8 toward the substrate 2. By supplying a high frequency power of 13.56 MHz to the solenoid coil 3, a high frequency electromagnetic field is generated in the space 7 inside the long chamber to generate plasma, and the substrate 2 is irradiated with the plasma from the plasma outlet 8. In addition, by performing scanning, heat treatment such as crystallization of the semiconductor film can be performed.

  As described above, the long chamber and the substrate mounting table 1 are arranged in a direction perpendicular to the longitudinal direction of the plasma nozzle 8 while the longitudinal direction of the plasma nozzle 8 and the substrate mounting table 1 are arranged in parallel. Therefore, the length of the plasma to be generated and the processing length of the substrate 2 can be configured to be substantially equal. In addition, the width of the cross section obtained by cutting the long chamber along a plane perpendicular to the central axis (the width of the space 7 inside the long chamber in FIG. 1A) is the width of the plasma ejection port 8 (FIG. 1A The width of the gap in) may be the same as or slightly larger. That is, the volume of plasma to be generated can be made extremely small compared to the conventional one. As a result, power efficiency is dramatically increased.

  Further, in the space 7 inside the long chamber, a relatively uniform plasma can be generated in the long direction, so that the substrate can be processed uniformly compared with the conventional example disclosed in Patent Document 6. it can.

(Embodiment 2)
The second embodiment of the present invention will be described below with reference to FIG.

  FIG. 3 shows the configuration of the plasma processing apparatus according to Embodiment 2 of the present invention, which is a cross-sectional view taken along a plane perpendicular to the longitudinal direction of the inductively coupled plasma torch unit, and corresponds to FIG. To do.

  In the second embodiment of the present invention, only the shapes of the quartz block 4 and the brass lid 6 are different from those of the first embodiment, and therefore other explanations are omitted.

  In FIG. 1, the gas supplied to the plasma gas manifold 9 is supplied as a plasma gas as a gas inlet provided in the quartz block 4 via a plasma gas supply pipe 10 formed of a hole provided in the quartz block 4. Although introduced into the space 7 inside the long chamber from the hole 11, in FIG. 3, the gas supplied to the plasma gas manifold 9 passes through the plasma gas supply pipe 10 formed of a hole provided in the brass lid 6. Thus, the gas is introduced into the space 7 inside the long chamber from the plasma gas supply hole 11 as a gas inlet serving as the outlet. The upper surface of the quartz block 4 is configured to be a long slit-like opening.

  In such a configuration, it is not necessary to perform complicated drilling on the quartz block 4, and thus the plasma processing apparatus can be configured more easily.

(Embodiment 3)
Embodiment 3 of the present invention will be described below with reference to FIG.

  FIG. 4 shows the configuration of the plasma processing apparatus according to Embodiment 3 of the present invention, which is a cross-sectional view of the inductively coupled plasma torch unit cut along a plane perpendicular to the longitudinal direction, and corresponds to FIG. To do.

  In FIG. 4, the quartz block 4 is configured by joining a first quartz plate 24 and a second quartz plate 25. A plasma gas supply pipe 21 is joined to the first quartz plate 24. In addition, the second quartz plate 25 is formed with recesses that become the space 7 inside the long chamber, the plasma outlet 8, the plasma gas manifold 9, and the plasma gas supply pipe 10 after joining. Speaking conversely, other than these concave portions constitute convex portions, and the quartz block 4 is configured to be joined using the convex portions as joint surfaces.

  In such a configuration, it is not necessary to drill a deep hole in the quartz block 4 and only a shallow recess is processed, so that the plasma processing apparatus can be configured more easily.

(Embodiment 4)
Embodiment 4 of the present invention will be described below with reference to FIGS.

  FIG. 5 shows the configuration of the plasma processing apparatus according to Embodiment 4 of the present invention, which is a cross-sectional view of the inductively coupled plasma torch unit cut along a plane perpendicular to the longitudinal direction, and corresponds to FIG. To do. FIG. 6 is an assembly configuration diagram of the inductively coupled plasma torch unit shown in FIG. 5, in which perspective views of parts (parts) are arranged.

  In FIG. 5, the quartz block 4 is configured by joining a first quartz plate 24 and a second quartz plate 25 as in the third embodiment. The solenoid coil 3 is disposed above the inductively coupled plasma torch unit T with the plasma gas manifold 9 and the plasma gas supply pipe 10 sandwiched between the space 7 inside the long chamber.

  In such a configuration, since the same number of quartz tubes 15 can be arranged on both sides of the quartz block 4, there is an advantage that cooling can be performed more effectively.

(Embodiment 5)
The fifth embodiment of the present invention will be described below with reference to FIG.

  FIG. 7 shows the configuration of the plasma processing apparatus according to the fifth embodiment of the present invention, which is a cross-sectional view of the inductively coupled plasma torch unit cut along a plane perpendicular to the longitudinal direction, and corresponds to FIG. To do.

  In FIG. 7, the conductor plate 26 is inserted from the upper part of the quartz block 4, and a part thereof is exposed in the space 7 inside the long chamber. The conductor plate 26 is formed with recesses that constitute the plasma gas manifold 9 and the plasma gas supply pipe 10.

  In this way, by exposing the conductor member to the space 7 inside the long chamber, capacitive coupling between the coil and the conductor member is strengthened, and discharge ignition with lower high-frequency power is possible. .

  In addition, since the plasma gas supply pipe 10 is surrounded by a grounded conductor, it is possible to effectively suppress undesirable discharge that may occur inside the plasma gas supply pipe 10.

(Embodiment 6)
The sixth embodiment of the present invention will be described below with reference to FIG.

  FIG. 8 shows the configuration of the plasma processing apparatus according to Embodiment 6 of the present invention, which is a cross-sectional view of the inductively coupled plasma torch unit cut along a plane perpendicular to the longitudinal direction, and corresponds to FIG. To do.

  In FIG. 8, a conductor plate 26 is inserted from the upper part of the quartz block 4 and a part thereof is exposed in the space 7 inside the long chamber. The conductor plate 26 is formed with recesses that constitute the plasma gas manifold 9 and the plasma gas supply pipe 10.

  In the fifth embodiment, the conductive plate 26 is inserted into the narrow gap provided in the quartz block 4, whereas in this embodiment, one side is opened in the thickness direction of the quartz block 4. A conductor plate 26 is disposed so as to close the opening. With such a configuration, it is possible to suppress the generation of stress due to the difference in the thermal expansion coefficient between the conductor plate 26 and the quartz block 4 that may occur when the temperature of the component member rises.

(Embodiment 7)
The seventh embodiment of the present invention will be described below with reference to FIG.

  FIG. 9 shows the configuration of the plasma processing apparatus according to Embodiment 7 of the present invention, which is a cross-sectional view of the inductively coupled plasma torch unit taken along a plane perpendicular to the longitudinal direction, and corresponds to FIG. To do.

  In FIG. 9, a conductor plate 26 is inserted into a hole provided in the side surface of the quartz block 4, and a part of the conductor plate 26 is exposed in the space 7 inside the long chamber. The concave portions constituting the plasma gas manifold 9 and the plasma gas supply pipe 10 are formed on one of the two quartz plates constituting the quartz block 4.

(Embodiment 8)
Hereinafter, an eighth embodiment of the present invention will be described with reference to FIGS.

  FIG. 10 shows the configuration of the plasma processing apparatus according to the eighth embodiment of the present invention, which is a cross-sectional view of the inductively coupled plasma torch unit cut along a plane perpendicular to the longitudinal direction, and corresponds to FIG. To do.

  10 and 11, a non-hollow copper and long solenoid coil 30 is disposed inside the quartz tube 12. That is, a quartz tube 12 as a cylindrical dielectric tube is joined to a side surface of the quartz block 4 as a dielectric block, and a solenoid coil 30 is disposed inside the quartz tube 12. The inside of the quartz tube 12 serves as a refrigerant flow path, and cooling of the solenoid coil 30 and cooling of the quartz block 4 joined thereto are realized.

  Both ends of the solenoid coil 30 penetrate the brass block 16 and are connected to a high-frequency matching circuit (not shown) through a copper member (not shown).

  With such a configuration, the quartz block 4 can be effectively cooled from both sides while keeping the distance between the solenoid coil 30 and the space 7 inside the long chamber small.

  The plasma processing apparatus and method described above merely exemplify typical examples of the scope of application of the present invention.

  For example, the inductively coupled plasma torch unit T may be scanned with respect to the fixed substrate mounting table 1, but the substrate mounting table 1 is scanned with respect to the fixed inductively coupled plasma torch unit T. May be.

  The various configurations of the present invention enable high-temperature treatment of the vicinity of the surface of the substrate 2, but can be applied to the crystallization of the semiconductor film for TFT and the modification of the semiconductor film for solar cell described in detail in the conventional example. Of course, the protective layer of the plasma display panel is cleaned and degassed, the surface of the dielectric layer consisting of an aggregate of silica particles is flattened and degassed, various electronic devices are reflowed, and the solid impurity source is reduced. It can be applied to various surface treatments such as plasma doping. Moreover, as a manufacturing method of a solar cell, it can apply also to the method of apply | coating the powder obtained by grind | pulverizing a silicon ingot on a base material, and irradiating this with a plasma and fuse | melting it, and obtaining a polycrystalline silicon film.

  It is also possible to use an ignition source in order to facilitate plasma ignition. As an ignition source, an ignition spark device used for a gas water heater or the like can be used.

  In the description, the term “thermal plasma” is used for simplicity. However, it is difficult to distinguish between thermal plasma and low temperature plasma. For example, Tanaka Yasunori “Non-equilibrium in thermal plasma” plasma nucleus Journal of Fusion Society, Vol. 82, no. 8 (2006) p. As described in 479-483, it is also difficult to classify plasma types based on thermal equilibrium alone. The present invention has an object of heat-treating a substrate, and can be applied to a technique for irradiating high-temperature plasma without being bound by terms such as thermal plasma, thermal equilibrium plasma, and high-temperature plasma.

In addition, the case where high-temperature heat treatment is uniformly performed in the vicinity of the surface of the base material for a very short time has been illustrated in detail. However, when the base material is subjected to low-temperature plasma processing by irradiating the base material with plasma or plasma and reactive gas flow at the same time. The present invention can also be applied. By mixing the reaction gas with the plasma gas, the plasma by the reaction gas is irradiated onto the substrate, and etching and CVD can be realized. Alternatively, by using a rare gas or a gas obtained by adding a small amount of H ₂ gas to a rare gas as a plasma gas, supplying a gas containing a reactive gas as a shielding gas, the plasma and the reactive gas flow are simultaneously irradiated onto the substrate. In addition, plasma processing such as etching, CVD, and doping can be realized. When a gas containing argon as a main component is used as the plasma gas, thermal plasma is generated as exemplified in detail in the embodiment. On the other hand, when a gas containing helium as a main component is used as the plasma gas, a relatively low temperature plasma can be generated. By such a method, processing such as etching and film formation can be performed without heating the substrate too much. Examples of the reactive gas used for etching include a halogen-containing gas such as C _x F _y (x and y are natural numbers), SF _{6, and the} like, and silicon and silicon compounds can be etched. If O ₂ is used as the reaction gas, it is possible to remove organic substances, resist ashing, and the like. The reactive gas used for CVD includes monosilane, disilane, and the like, and silicon or silicon compound can be formed. Alternatively, a silicon oxide film can be formed by using a mixed gas of O ₂ and an organic gas containing silicon typified by TEOS (Tetraethoxysilane). In addition, various low-temperature plasma treatments such as surface treatment for modifying water repellency and hydrophilicity are possible. Compared to the prior art (for example, described in Patent Document 7), since it is an inductive coupling type, even if a high power density per unit volume is applied, it is difficult to shift to arc discharge, so a higher density plasma is generated. As a result, a high reaction rate can be obtained, and the entire desired region to be treated of the substrate can be processed in a short time.

  As described above, the present invention can be applied to the crystallization of the TFT semiconductor film and the modification of the semiconductor film for the solar cell, as well as cleaning the protective layer of the plasma display panel, reducing the degassing, Uniformity in the vicinity of the surface of the substrate for only a short time in various surface treatments such as surface flattening of dielectric layers consisting of aggregates, reduction of degassing, reflow of various electronic devices, plasma doping using solid impurity sources, etc. In the high temperature heat treatment, the present invention is useful for treating the entire desired region of the base material in a short time. In addition, it is a useful invention for processing a desired whole region of a substrate in a short time in low temperature plasma processing such as etching, film formation, doping, and surface modification in manufacturing various electronic devices. .

DESCRIPTION OF SYMBOLS 1 Base material mounting base 2 Base material T Inductive coupling type plasma torch unit 3,30 Solenoid coil 4 Quartz block 6 Brass lid 7 Space inside long chamber 8 Plasma jet 9 Plasma gas manifold 10 Plasma gas supply piping 11 Plasma gas supply Hole 12 Quartz tube 13 Shield gas nozzle 14 Shield gas manifold 15 Quartz tube 16 Brass block 17 Resin case 18 Cooling water manifold 21 Plasma gas supply pipe 22 Thin film

Claims (12)

A long chamber provided in the dielectric block, a gas inlet for supplying gas into the chamber, and a dielectric made of a dielectric material joined to the dielectric block and provided in parallel to the long chamber. A cylindrical tube, a long solenoid coil provided in the cylindrical tube, and a high-frequency power source connected to the solenoid coil,
The long chamber includes a long opening;
A substrate mounting table that is arranged to face the opening and holds the substrate,
The longitudinal direction of the chamber and the longitudinal direction of the opening are arranged in parallel,
A moving mechanism that allows the chamber and the substrate mounting table to move relatively in a direction perpendicular to the longitudinal direction of the opening;
A plasma processing apparatus. The plasma processing apparatus according to claim 1, wherein the dielectric block is formed by joining two thin plates made of a dielectric having at least one convex portion with the convex portion as a joint surface. . The plasma processing apparatus according to claim 1, wherein the inside of the cylindrical tube is a refrigerant flow path. 2. The plasma processing apparatus according to claim 1, wherein a dielectric cylindrical tube serving as a refrigerant flow path is joined to the dielectric block separately from the cylindrical tube provided with the solenoid coil. The plasma processing apparatus according to claim 4, wherein the refrigerant flow path communicates with two refrigerant manifolds provided on both sides of the long chamber in the longitudinal direction. A long chamber provided in the dielectric block, a gas inlet for supplying gas into the chamber, a hollow conductor pipe joined to the dielectric block, and in the long chamber A long solenoid coil provided in parallel, and a high frequency power source connected to the solenoid coil,
The long chamber includes a long opening;
A substrate mounting table that is arranged to face the opening and holds the substrate,
The longitudinal direction of the chamber and the longitudinal direction of the opening are arranged in parallel,
A moving mechanism that allows the chamber and the substrate mounting table to move relatively in a direction perpendicular to the longitudinal direction of the opening;
A plasma processing apparatus. 7. The plasma processing apparatus according to claim 6, wherein the dielectric block is formed by joining two thin plates made of a dielectric having at least one convex portion with the convex portion as a joint surface. . The plasma processing apparatus according to claim 6, wherein the inside of the solenoid coil is a refrigerant flow path. The plasma processing apparatus according to claim 6, wherein a dielectric cylindrical tube serving as a refrigerant flow path is joined to the dielectric block separately from the solenoid coil. The plasma processing apparatus according to claim 9, wherein the refrigerant flow path communicates with two refrigerant manifolds provided on both sides of the long chamber in the longitudinal direction. While supplying the gas into the long chamber surrounded by the dielectric block, the gas is ejected from the slit-shaped opening formed in the long chamber toward the base material, and high-frequency power is supplied to the coil. In the plasma processing method for generating a high-frequency electromagnetic field in the long chamber,
A plasma processing method of processing the surface of the base material while relatively moving the chamber and the base material in a direction perpendicular to the longitudinal direction of the opening,
The coil comprises a solenoid coil provided in a dielectric cylindrical tube joined to the dielectric block;
A plasma processing method characterized by the above. While supplying the gas into the long chamber surrounded by the dielectric block, the gas is ejected from the slit-shaped opening formed in the long chamber toward the base material, and high-frequency power is supplied to the coil. In the plasma processing method for generating a high-frequency electromagnetic field in the long chamber,
A plasma processing method of processing the surface of the base material while relatively moving the chamber and the base material in a direction perpendicular to the longitudinal direction of the opening,
The coil is made of a long solenoid coil joined to the dielectric block, made of a hollow conductor tube, and provided in parallel to the long chamber;
A plasma processing method characterized by the above.

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