JP5500097B2 - Inductively coupled plasma processing apparatus and method - Google Patents

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, and the like. The present invention relates to an inductively coupled plasma processing apparatus and 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. 14 is a schematic diagram for explaining a method of crystallizing a semiconductor film using this thermal plasma.

  In the figure, a thermal plasma generator 41 includes a cathode 42 and an anode 43 disposed opposite to the cathode 42 by a predetermined distance. The cathode 42 is made of a conductor such as tungsten. The anode 43 is made of a conductor such as copper, for example. Further, the anode 43 is formed in a hollow shape, and is configured so that water can be cooled through the hollow portion. The anode 43 is provided with an ejection hole (nozzle) 44. When a direct current (DC) voltage is applied between the cathode 42 and the anode 43, an arc discharge is generated between the two electrodes. In this state, by flowing a gas such as argon gas between the cathode 42 and the anode 43 under atmospheric pressure, the thermal plasma 45 can be ejected from the ejection hole 44. 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 47 (for example, an amorphous silicon film) is formed on the substrate 46, and thermal plasma (thermal plasma jet) 45 is applied to the semiconductor film 47. At this time, the thermal plasma 45 is applied to the semiconductor film 47 while being relatively moved along a first axis (left and right direction in the illustrated example) parallel to the surface of the semiconductor film 47. That is, the thermal plasma 45 is applied to the semiconductor film 47 while scanning in the first axis direction. Here, “relatively move” means that the semiconductor film 47 (and the substrate 46 supporting it) and the thermal plasma 45 are relatively moved, and only one of them is moved and both are moved together. Any of the cases are included. By such scanning of the thermal plasma 45, the semiconductor film 47 is heated by the high temperature of the thermal plasma 45 to obtain a crystallized semiconductor film 48 (polysilicon film in this example) (see, for example, Patent Document 1). ).

  FIG. 15 is a conceptual diagram showing the relationship between the depth from the outermost surface and the temperature. As shown in FIG. 15, only the vicinity of the surface can be processed at a high temperature by moving the thermal plasma 45 at a high speed. After the thermal plasma 45 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 42, 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 portion 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.

  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 8).

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 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 8 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 in the vicinity of the surface of the base material for a very short time, or the base material is irradiated with plasma by the reactive gas or plasma and the reactive gas flow at the same time. Thus, an object of the present invention is to provide an inductively coupled plasma processing apparatus and method capable of processing the entire desired region of the substrate in a short time when the substrate is subjected to low temperature plasma treatment.

An inductively coupled plasma processing apparatus according to a first aspect of the present invention is a slit-shaped dielectric cylindrical chamber having a single opening, a gas inlet for supplying gas into the chamber, and the chamber. and arcuate conductors for generating an inductively coupled plasma in the chamber by flowing a high frequency current provided around, is disposed to face the opening portion, and a mounting table base for holding the base material, the An inductively coupled plasma processing apparatus comprising: the chamber and the base in a direction perpendicular to the longitudinal direction of the opening, wherein the longitudinal direction of the chamber and the longitudinal direction of the opening are arranged in parallel. A plurality of arc-shaped conductors that are parallel and electrically connected to each other, and a plurality of the arc-shaped conductors are electrically connected to each other . Conductor arc breaks Characterized by providing the opening in the portion.

  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 treatment 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.

  Preferably, both ends of the arcuate conductor are connected to a high-frequency applying rod and a grounding rod made of a conductor, and the longitudinal direction of the high-frequency applying rod and the grounding rod and the longitudinal direction of the opening are arranged in parallel. It is desirable that

With such a configuration, it is possible to easily apply a high frequency to the arcuate conductor .

Also preferably, two refrigerant manifolds are provided on both sides in the longitudinal direction of the cylindrical chamber,
It is desirable that the cylindrical chamber be provided with a refrigerant flow path that communicates the two refrigerant manifolds.

  With such a configuration, efficient cooling of the plasma processing apparatus can be easily performed.

Also preferably, two refrigerant manifolds are provided on both sides in the longitudinal direction of the cylindrical chamber,
The cylindrical chamber includes a refrigerant flow path that communicates the two refrigerant manifolds,
The high-frequency application rod and the grounding rod are hollow tubes, and one of the high-frequency application rod or the grounding rod communicates with one of the two refrigerant manifolds, and the high-frequency application rod or the grounding rod It is desirable that the other one communicates with the other one of the two refrigerant manifolds.

With such a configuration, in addition to efficient cooling of the plasma processing apparatus, it is possible to easily cool the arc-shaped conductor , the high-frequency applying rod, and the grounding rod.

  Preferably, a plurality of gas pipes communicating with the gas introduction port are provided between the plurality of arcuate conductors.

  With such a configuration, a uniform gas flow can be easily formed in the longitudinal direction.

Preferably, the cylindrical chamber, the arc-shaped conductor , the high-frequency applying rod, and the grounding rod are accommodated in a ground potential conductor cover, and an insulation is provided between the high-frequency applying rod and the conductor cover. It is desirable that a bar be placed.

  With such a configuration, high-frequency leakage can be effectively prevented, and undesirable abnormal discharge can be effectively prevented.

  Preferably, the internal space of the cylindrical chamber is a slit provided in the cylindrical chamber.

  With such a configuration, the cylindrical chamber can be easily formed.

  Further, the width of the slit provided in the cylindrical chamber may be constant toward the opening, may be gradually widened toward the opening, or may be It may be narrowed gradually.

In the inductively coupled plasma processing method of the second invention of the present application, while supplying gas into the cylindrical chamber, the gas is ejected from a single opening to the substrate in the form of a slit formed in the chamber. In the inductively coupled plasma processing method for generating inductively coupled plasma in the chamber by supplying a high frequency current to an arcuate conductor provided around the chamber , a plurality of the arcuate conductors are parallel to each other. When the surface of the base material is processed while relatively moving the chamber and the base material in a direction perpendicular to the longitudinal direction of the opening and electrically connected to the plurality of conductors. The surface of the base material is treated in a state in which a high-frequency current of a phase is passed and the opening is disposed in a portion where the arc of the arc-shaped conductor is interrupted.

  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 treatment 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.

  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 treatment 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 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 1 of this invention Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 2 of this invention. The perspective view 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. The perspective view 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. 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 FIGS.

  1A (a) and 1 (b) show a configuration of a plasma processing apparatus according to Embodiment 1 of the present invention, and are cross-sectional views taken along a plane perpendicular to the longitudinal direction of an inductively coupled plasma torch unit. .

  1B (c) and 1 (d) 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 (c) is a cross-sectional view taken along broken lines A to A ′ in FIG. 1A (b), FIG. 1B (d) is a cross-sectional view taken along broken lines BB ′ in FIG. 1A (b), and FIG. ) Is a cross-sectional view taken along broken lines C to C ′ in FIG. 1B (c), and FIG. 1A (b) is a cross-sectional view taken along broken lines D to D ′ in FIG. 1B (c).

  FIG. 2 is an assembly configuration diagram of the inductively coupled plasma torch unit shown in FIGS. 1A and 1B, and is a perspective view of each component. FIG. 3 is an enlarged view of a portion E in FIG. 1B (d).

  1 to 3, the base material 2 is placed on the base material placing table 1. In the inductively coupled plasma torch unit T, a copper tube 3 as an arcuate conductor forming a coil is disposed around a quartz block 4 constituting a cylindrical chamber made of a dielectric. A copper tube 3 and a quartz block 4 are accommodated in a brass block 5 provided below the quartz block 4 and a metal cover 6. Since the brass block 5 and the cover 6 are grounded, high-frequency leakage can be effectively prevented and undesirable abnormal discharge can be effectively prevented.

  A space 7 inside the cylindrical chamber is a slit provided in the quartz block 4. The plasma generated in the space 7 inside the cylindrical chamber is ejected toward the base material 2 from the plasma ejection port 8 as a slit-shaped opening in the cylindrical chamber. A portion where the arc of the arcuate conductor made of the copper tube 3 is interrupted corresponds to the lower part of the figure, and a plasma jet port 8 serving as an opening is provided there. Further, the longitudinal direction of the chamber and the longitudinal direction of the plasma outlet 8 are arranged in parallel.

  A plasma gas manifold 9 is provided above the cover 6. The gas supplied to the plasma gas manifold is provided in the quartz block 4 via a plasma gas supply pipe 10 made of a conductor, and is formed into a cylindrical chamber through a plasma gas supply hole 11 having an opening as a gas introduction port below. It is introduced into the internal space 7. The copper tube 3 and the plasma gas supply pipe 10 are filled with a resin block 12 in order to suppress discharge in the space between them. As described above, since the plurality of plasma gas supply pipes 10 communicating with the gas inlets are provided between the plurality of arc-shaped copper tubes 3, a uniform gas flow can be easily formed in the longitudinal direction.

  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 oxygen and carbon dioxide in the atmosphere, which are unnecessary or have an adverse effect on the processing. It is possible to reduce contamination of the plasma irradiation surface.

  Inside the copper tube 3, water as an insulating refrigerant flows through the inside of the upstream copper tube 15 as a high frequency application rod and the downstream copper tube 16 as a grounding rod. That is, the space inside the copper tube 3 and the space inside the hollow upstream copper tube 15 and the downstream copper tube 16 are configured to communicate with each other. The quartz block 4 and the brass block 5 are provided with a cooling water pipe 17 penetrating them. These water passages (refrigerant flow passages) communicate with a cooling water manifold 20 as a refrigerant manifold formed by a space between the resin case 19 provided outside the brass block 18 and the brass block 18.

  The resin case 19 is provided with one coolant inlet / outlet 21 as a refrigerant inlet / outlet, and the water cooling piping to the torch unit T is very simple. Can be configured. That is, two refrigerant manifolds 20 are provided on both sides in the longitudinal direction of the cylindrical chamber, and each member is provided with a refrigerant flow path communicating with the two refrigerant manifolds 20.

  In addition, the water supply / drainage to the upstream side copper pipe 15 and the downstream side copper pipe 16 is the cooling water inlet / outlet 23 provided in the copper pipe extension part 22 extended in the reverse direction (hole provided in the side surface of a cylindrical copper pipe). Done from. That is, the cooling water inlet / outlet 23 is disposed in the cooling water manifold 20, and one of the upstream copper pipe 15 and the downstream copper pipe 16 communicates with one of the two refrigerant manifolds, and the upstream copper pipe 15 and The other one of the downstream copper pipes 16 communicates with the other one of the two refrigerant manifolds. The upstream copper pipe 15 and the downstream copper pipe 16 pass through the resin bush 24 penetrating the brass block 18 and pass through the high frequency introduction terminal hole 25 and the ground terminal hole 26 provided in the resin case 19. And is connected to a high-frequency matching circuit (not shown) through the copper plate 28.

  Further, the upstream copper pipe 15 and the downstream copper pipe 16 are insulated from the brass block 5 and the cover 6 which are grounded by a resin block 29 as an insulating rod, and the brass which is grounded by a resin block 30. Insulation with the block 18 is achieved.

  As described above, in the present embodiment, since a plurality of cooling water pipes 17 having a circular cross section penetrating the quartz block 4 are provided, in the technique described in Patent Document 6 shown in the conventional example, a double pipe is used. Compared to the case of water cooling, a much larger amount of refrigerant can be flowed.

  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 copper tube 3 forming a coil from a high-frequency power source (not shown) while gas is being injected from the plasma outlet 8 toward the substrate 2 while supplying gas into the cylindrical chamber. By doing so, plasma is generated in the space 7 inside the cylindrical chamber, and the thin film 31 on the base material 2 can be plasma-treated by irradiating the base material 2 with plasma from the plasma outlet 8.

  In this configuration, the copper tube 3 as a coil is formed of an arc-shaped conductor provided around the chamber, and a plasma jet port 8 as an opening is provided in a portion where the arc of the arc-shaped conductor is interrupted. Thus, the substrate 2 is processed by relatively moving the chamber and the substrate 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 FIGS. 1A (a) and (b) and in the direction perpendicular to the paper surface in FIGS. 1B (c) and (d).

  The plurality of copper tubes 3 are arranged in parallel, and both ends thereof are connected to the upstream copper tube 15 and the downstream copper tube 16. High frequency power is supplied to the upstream copper tube 15, and the downstream copper tube 16 is grounded. Therefore, a high-frequency current having the same phase flows through the plurality of copper tubes 3. Further, since the arc-shaped copper tube 3 is arranged so as to surround the space 7 inside the cylindrical chamber, the induction electromagnetic field excited by the high-frequency current flowing through the copper tube 3 is strengthened in the space 7 inside the cylindrical chamber. A plasma can be generated efficiently. Further, by adopting such a configuration, the inductance of the coil becomes extremely small, and the power efficiency can be improved. This is particularly effective when the width of the base material 2 to be treated is large, that is, when the inductively coupled plasma torch unit T is elongated in the longitudinal direction.

  The longitudinal direction of the upstream copper tube 15 and the downstream copper tube 16 and the longitudinal direction of the plasma jet port 8 are arranged in parallel. With such a configuration, it is possible to easily apply a high frequency to the coil.

  Various gases can be used as the gas supplied into the cylindrical 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 component 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). A portion of the brass block 5 that is downstream of the plasma outlet 8 forms a space that gradually widens toward the substrate 2. With such a configuration, it is possible to suppress a decrease in the plasma density due to the plasma contact with the brass block 5, and at the same time, it is possible to provide the cooling water pipe 17 at a position close to the portion in contact with the plasma.

  In this configuration, since the length of the plasma injection port 8 in the longitudinal direction is equal to or greater than the width of the base material 2, one-time scanning (the torch unit T and the base material mounting table 1 are relatively moved). The entire thin film 31 in the vicinity of the surface of the substrate 2 can be processed.

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 the gas outlet into the cylindrical chamber and gas is jetted from the plasma outlet 8 toward the substrate 2. Further, by supplying high frequency power of 13.56 MHz to the copper tube 3 forming a coil, a high frequency electromagnetic field is generated in the space 7 inside the cylindrical chamber to generate plasma, and the plasma is supplied from the plasma outlet 8 to the base material. By irradiating 2 and scanning, heat treatment such as crystallization of the semiconductor film can be performed.

  In this way, the cylindrical 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. Further, the width of the cross section obtained by cutting the cylindrical chamber along a plane perpendicular to the central axis (the width of the chamber internal space 7 in FIG. 1B (c)) is the width of the plasma ejection port 8 (the gap in FIG. 1B (c)). It is sufficient if it is slightly larger than 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 internal space of the cylindrical chamber, a relatively uniform plasma can be generated in the longitudinal direction, so that the substrate can be processed uniformly compared to the conventional example disclosed in Patent Document 6. .

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

  FIG. 4 shows the configuration of the plasma processing apparatus according to Embodiment 2 of the present invention, which is a cross-sectional view of the inductively coupled plasma torch unit taken along a plane parallel to the longitudinal direction, and corresponds to FIG. 1B (c). To do. FIG. 5 is an assembly configuration diagram (part) of the inductively coupled plasma torch unit shown in FIG. 4, in which perspective views of respective components are arranged.

  In the second embodiment of the present invention, since the shape of the resin block 12 is different from that of the first embodiment and only the resin block 33 is added, the other description is omitted.

  A semi-cylindrical groove is formed in the resin block 12 and the resin block 33 so that no gap is formed between the copper tube 3 and the resin block 12. With such a configuration, an abnormal discharge around the copper tube 3 (a space between the copper tube 3 and the quartz block 4 or the cover 6) can be effectively suppressed.

(Embodiment 3)
Hereinafter, Embodiment 3 of the present invention will be described with reference to FIGS.

  FIG. 6 shows the configuration of the plasma processing apparatus in accordance with the third exemplary embodiment of the present invention, and is a cross-sectional view taken along a plane perpendicular to the longitudinal direction of the inductively coupled plasma torch unit. It corresponds to b). FIG. 7 is an assembly configuration diagram (part) of the inductively coupled plasma torch unit shown in FIG. 6, in which perspective views of the respective parts are arranged.

  In the third embodiment of the present invention, the shapes of the resin block 12 and the resin block 29 are different from those of the first embodiment, and only the resin block 33 and the resin block 34 are added. Is omitted.

  A semi-cylindrical groove is formed in the resin block 12 and the resin block 33 so that no gap is formed between the copper tube 3 and the resin block 12. With such a configuration, an abnormal discharge around the copper tube 3 (a space between the copper tube 3 and the quartz block 4 or the cover 6) can be effectively suppressed. Similarly, a semi-cylindrical groove is also formed in the resin block 34, and abnormal discharge around the copper tube 3 (the space between the copper tube 3 and the quartz block 4) can be effectively suppressed. Since the resin block 34 is inserted between the copper tube 3 and the quartz block 4, the width between the upstream copper tube 15 and the downstream copper tube 16 is larger than the width of the quartz block 4. Thereby, the shape of the resin block 29 is formed into a U-shape so that there is no gap between the upstream copper pipe 15 and the downstream copper pipe 16 and the quartz block 4.

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

  FIG. 8 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 taken along a plane parallel to the longitudinal direction, and corresponds to FIG. 1B (c). To do. FIG. 9 is an assembly configuration diagram (part) of the inductively coupled plasma torch unit shown in FIG. 8, in which perspective views of components are arranged.

  In the fourth embodiment of the present invention, only the shapes of the copper tube 3 and the resin block 12 are different from those of the first embodiment, and therefore other explanations are omitted.

  The copper tube 3 constitutes a strip-shaped coil and includes two through holes for arranging the plasma gas supply pipe 10. With such a configuration, the cross-sectional area of the copper tube as the coil is increased, so that high-frequency driving with less loss is possible.

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

  FIG. 10 shows the configuration of the plasma processing apparatus according to Embodiment 5 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 Embodiment 1 of the present invention, the cylindrical chamber is constituted by a rectangular parallelepiped quartz block. However, in Embodiment 5 of the present invention, a plurality of cylindrical quartz tubes 35 are arranged in a gate shape. Thus, a slit-shaped cylindrical chamber is configured.

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

  FIG. 11 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. 1A (a). To do.

  In the first embodiment of the present invention, the case where the width of the slit (space 7 inside the cylindrical chamber) provided in the cylindrical chamber is constant toward the plasma ejection port 8 as the opening is illustrated. In Embodiment 6 of the present invention, the width of the slit (space 7 inside the cylindrical chamber) provided in the cylindrical chamber is gradually narrowed toward the plasma outlet 8 as the opening. With such a configuration, it is possible to irradiate plasma in a narrower range while ensuring the generation of plasma.

(Embodiment 7)
Hereinafter, a seventh embodiment of the present invention will be described with reference to FIG.

  FIG. 12 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. 1A (a). To do.

  In the first embodiment of the present invention, the case where the width of the slit (space 7 inside the cylindrical chamber) provided in the cylindrical chamber is constant toward the plasma ejection port 8 as the opening is illustrated. In Embodiment 7 of the present invention, the width of the slit (space 7 inside the cylindrical chamber) provided in the cylindrical chamber is gradually increased toward the plasma outlet 8 as the opening. With such a configuration, it is possible to irradiate plasma over a wider range while maintaining high plasma generation efficiency.

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

  FIG. 13 shows the configuration of the plasma processing apparatus according to the eighth embodiment of the present invention, and is an assembly configuration diagram (part) of the inductively coupled plasma torch unit, in which perspective views of the respective components are arranged.

  In the eighth embodiment of the present invention, only the shape of the coil is different from that of the first embodiment, and therefore other explanations are omitted.

  The coil is composed of a copper tube 3 in which a plurality of arc-shaped conductors are arranged in parallel and meanderingly arranged so that a high-frequency current having an opposite phase flows through a plurality of arc-shaped conductors adjacent to each other. That is, the coil has a shape that can be drawn with a single stroke, and is arranged so as to surround the quartz block 4 in a zigzag shape. With such a configuration, an induction electromagnetic field formed between adjacent copper tubes in the slit (space 7 inside the cylindrical chamber) is strengthened, so that efficient plasma generation is possible.

  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.

  Further, the plasma gas supply pipe 10 may be extended until it penetrates the quartz block 4 and is exposed to the space 7 inside the cylindrical chamber. When the plasma gas supply pipe 10 is made of a dielectric, a high frequency electromagnetic field is irradiated inside the pipe, and an undesirable discharge may occur inside the pipe. In each embodiment of the present invention, the case where the plasma gas supply pipe 10 is made of metal is exemplified, but this is for suppressing the above-described undesirable discharge. In order to further enhance the effect, it is effective to surround a portion that is not desired to be discharged with a conductor, and the plasma gas supply pipe 10 extends through the quartz block 4 until it is exposed to the space 7 inside the cylindrical chamber. It is preferable to do so.

  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 performed in the vicinity of the surface of the base material uniformly for a very short time is illustrated in detail. 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, the plasma and the reactive gas flow are simultaneously irradiated onto the substrate by supplying a gas containing a reactive gas as a shielding gas while using a rare gas or a gas obtained by adding a small amount of H ₂ gas to the rare gas as the plasma gas. 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. As a reactive gas used for etching, a halogen-containing gas, for example, C _x F _y (x and y are natural numbers), SF ₆
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 Copper tube 4 Quartz block 5 Brass block 6 Cover 7 Space inside cylindrical chamber 8 Plasma outlet 9 Plasma gas manifold 10 Plasma gas supply pipe 11 Plasma gas supply Hole 12 Resin block 13 Shield gas nozzle 14 Shield gas manifold 15 Upstream copper pipe 16 Downstream copper pipe 17 Cooling water pipe 18 Brass block 19 Resin case 20 Cooling water manifold 21 Cooling water inlet / outlet 22 Copper pipe extension 23 Cooling water inlet / outlet 24 Resin Bush 25 High frequency lead terminal hole 26 Ground terminal hole 27 Copper block 28 Copper plate 29 Resin block 30 Resin block 31 Thin film 32 Plasma gas supply piping

Claims (11)

A dielectric cylindrical chamber with a slit and a single opening;
A gas inlet for supplying gas into the chamber;
An arcuate conductor provided around the chamber for generating inductively coupled plasma in the chamber by flowing a high-frequency current ;
A substrate mounting table disposed opposite to the opening and holding the substrate;
An inductively coupled plasma processing apparatus comprising:
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 plurality of the arcuate conductors are parallel and electrically connected to each other, and a high-frequency current having the same phase flows through the plurality of conductors,
An inductively coupled plasma processing apparatus, wherein the opening is provided in a portion where the arc of the arc-shaped conductor is interrupted. The arcuate ends of the conductors is connected to the RF applying rod and the ground rod made of a conductor, the longitudinal direction of the high-frequency applying rod and the ground rod and the longitudinal direction of the opening is parallel to, claim 2. The inductively coupled plasma processing apparatus according to 1. Two refrigerant manifolds are provided on both sides in the longitudinal direction of the cylindrical chamber,
The inductively coupled plasma processing apparatus according to claim 1 , wherein the cylindrical chamber includes a refrigerant flow path that communicates the two refrigerant manifolds. Two refrigerant manifolds are provided on both sides in the longitudinal direction of the cylindrical chamber,
The cylindrical chamber includes a refrigerant flow path that communicates the two refrigerant manifolds,
The high-frequency application rod and the grounding rod are hollow tubes, and one of the high-frequency application rod or the grounding rod communicates with one of the two refrigerant manifolds, and the high-frequency application rod or the grounding rod among other hand it is in fluid other one the communicating of said two refrigerant manifolds, inductively coupled plasma processing apparatus according to claim 1. Wherein the plurality of between the arc-shaped conductor, a plurality of gas pipe communicating with the gas inlet port is provided, inductively coupled plasma processing apparatus according to claim 1. The cylindrical chamber, the arc-shaped conductor , the high-frequency applying rod, and the grounding rod are housed in a conductor cover having a ground potential, and an insulating rod is disposed between the high-frequency applying rod and the conductor cover. , inductively coupled plasma processing apparatus according to claim 1. The inner space of the tubular chamber is a slit provided in the tubular chamber, an inductively coupled plasma processing apparatus according to claim 1. Width of the slit provided in the tubular chamber is constant toward the opening, inductively coupled plasma processing apparatus of claim 6. Width of the slit provided in the tubular chamber is gradually widened toward the opening, inductively coupled plasma processing apparatus of claim 6. Width of the slit provided in the tubular chamber is gradually narrower toward the opening, inductively coupled plasma processing apparatus of claim 6. While supplying the gas into the cylindrical chamber, the gas is ejected from the single opening to the substrate in the form of a slit formed in the chamber, and the high frequency is applied to the arc-shaped conductor provided around the chamber. In the inductively coupled plasma processing method for generating inductively coupled plasma in the chamber by supplying a current ,
The arcuate conductors are parallel to each other and electrically connected,
When 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, a high-frequency current having the same phase flows through a plurality of conductors, A method of inductively coupled plasma processing, comprising: treating a surface of the base material in a state where the opening is disposed at a portion where the arc of the arc-shaped conductor is interrupted.

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