JP5821984B2 - Manufacturing method of electronic device - 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 The present invention relates to an electronic device manufacturing 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 sealed 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. 16 is a schematic diagram for explaining a method of crystallizing a semiconductor film 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. 17 is a conceptual diagram showing the relationship between the depth from the outermost surface and the temperature. As shown in the figure, by moving the thermal plasma 35 at a high speed, only the vicinity of the surface can be processed at a high temperature. 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 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.

  In addition, in the inductively coupled high-frequency plasma torch as shown in the technique described in Patent Document 6 shown in the conventional example, a cylindrical type has been put to practical use for analysis or thermal spraying. The generation efficiency is poor, and the discharge becomes unstable when the gas flow rate is increased.

  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. An electronic device manufacturing method capable of generating plasma stably and efficiently when a substrate is subjected to low-temperature plasma treatment, and capable of efficiently processing the entire desired region of the substrate in a short time. It is intended to provide.

The method for manufacturing an electronic device of the present invention has the following characteristics.
(1) while supplying gas to the first quartz block and a second quartz block enclosed by the ring-shaped chamber, it is mounted on the substrate mounting table from the line-shaped opening in communication with elongate the annular chamber To blow gas toward the substrate.
[2] it is provided in the vicinity of the annular chamber, and, in the longitudinal direction and parallel orientation of the openings by supplying high frequency power to the coils of elongated shape, by generating a high-frequency electromagnetic field in the annular chamber flop Raising the laser.
[3] Treating the surface of the substrate while relatively moving the annular chamber and the substrate mounting table in a direction perpendicular to the longitudinal direction of the opening.
[4] The electronic device is manufactured using an inductively coupled plasma torch.

  Due to such characteristics, when the high temperature heat treatment is performed uniformly in the vicinity of the surface of the substrate for a very short time, or the substrate is irradiated with plasma by the reaction gas or plasma and the reaction gas flow at the same time, the substrate is subjected to the low temperature plasma treatment. At this time, plasma can be generated stably and efficiently.

  In the method for manufacturing an electronic device according to the present invention, it is desirable that a coolant channel be provided in the dielectric member in parallel to the longitudinal direction of the opening. Moreover, it is desirable that the passage for communicating the annular chamber and the opening is formed with a gap of 1 mm or less. Further, the thickness of the annular chamber is preferably 1 mm or more and 10 mm or less, and the outer diameter of the annular chamber is more preferably 10 mm or more. Furthermore, it is preferable that a passage for communicating the annular chamber and the opening is provided in parallel to the longitudinal direction of the opening.

  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. At this time, plasma can be generated stably and efficiently, and the entire desired region to be treated of the substrate can be efficiently treated 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. 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. Sectional drawing 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 Embodiment 9 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 10 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 11 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 12 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 13 of this invention. Sectional drawing which shows the structure of the plasma processing apparatus in Embodiment 14 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. FIG. 1A is a cross-sectional view taken along the broken line A-A ′ in FIG.

  1B is a cross-sectional view taken along the broken line BB ′ in FIG. 1A, FIG. 1C is a cross-sectional view taken along the broken line CC ′ 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 conductor solenoid coil 3 is disposed in the vicinity of the first quartz block 4 and the second quartz block 5. The long chamber made of a dielectric is defined by a space surrounded by the first quartz block 4 and the second quartz block 5 (space 7 inside the long chamber). The inner wall surface of the long chamber close to the solenoid coil 3 is a curved surface parallel to the solenoid coil 3.

  In such a configuration, since the distance from the solenoid coil 3 to the long chamber becomes equal at any part of the solenoid coil 3, inductively coupled plasma can be generated with a small high-frequency power, and efficient plasma generation can be achieved. realizable.

  The inductively coupled plasma torch unit T is entirely surrounded by a shield member (not shown) made of a grounded conductor, which can effectively prevent high-frequency leakage (noise) and effectively prevent undesirable abnormal discharge. Can be prevented.

  The space 7 inside the long chamber is surrounded by the outer wall surface of the second quartz block 5 as an internal dielectric block and the inner wall surface of the first quartz block 4 as an external dielectric block into which the space is inserted. That is, the entire long chamber is surrounded by a dielectric. The space 7 inside the long chamber is annular. The term “annular” as used herein means a shape that forms a continuous string of strings, and is not limited to a circle.

  In the present embodiment, a racetrack shape (a series of closed string-like shapes formed by connecting a straight line portion having two long sides and a circle, an ellipse, or a straight line having two short sides at both ends thereof. (Shape) is illustrated. The plasma P generated in the space 7 inside the long chamber is ejected toward the base material 2 from the plasma outlet 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 inside the second quartz block 5. The gas supplied to the plasma gas manifold 9 from the plasma gas supply pipe 10 passes through a plasma gas supply hole 11 (through hole) as a gas introduction part provided in the second quartz block 5 and is a space inside the long chamber. 7 is introduced. With such a configuration, a uniform gas flow in the longitudinal direction can be easily realized. The flow rate of the gas introduced into the plasma gas supply pipe 10 is controlled by providing a flow rate control device such as a mass flow controller upstream thereof.

  The plasma gas supply hole 11 is provided with a plurality of round holes in the longitudinal direction, but may be a long slit.

  Further, a shield gas nozzle 13 as a shield gas supply port 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 shield gas supply port may be a slit having a shape that is long in the direction parallel to the long direction of the plasma jet port 8 or the direction that is parallel to the long direction of the plasma jet port 8. It may be a number of holes arranged side by side.

  The solenoid coil 3 is made of a hollow copper tube, and the inside is a refrigerant flow path. That is, cooling is possible by flowing a coolant such as water. The first quartz block 4 and the second quartz block 5 are provided with a coolant channel 15 in parallel to the longitudinal direction of the plasma jet port 8. The first quartz block 4 is also provided with a coolant channel 15 in a direction perpendicular to the longitudinal direction of the plasma jet port 8, and the coolant channel 15 parallel to the longitudinal direction of the plasma jet port 8 Crossing three-dimensionally, refrigerant is supplied and discharged from the outside.

  Further, in the second quartz block 5, as shown in FIG. 1 (c), the refrigerant flow paths are merged and bundled to supply and discharge the refrigerant to and from the outside. Since these refrigerant flow paths have a circular cross section, even when a large amount of refrigerant is flowed, deformation of the constituent members hardly occurs due to the internal pressure. In other words, in the present embodiment, a much larger amount of refrigerant can be allowed to flow than in the case of water-cooling as a double-pipe structure in the technique described in Patent Document 6 shown in the conventional example, and effective cooling is achieved. Is possible.

  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 the plasma P in the space 7 inside the long chamber and irradiating the substrate 2 with 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. Further, by supplying high frequency power of 13.56 MHz to the solenoid coil 3, a plasma P is generated by generating a high frequency electromagnetic field in the space 7 inside the long chamber, and the plasma is supplied from the plasma outlet 8 to the base material 2. By performing irradiation and scanning, heat treatment such as crystallization of the semiconductor film can be performed.

As conditions for plasma generation, the distance between the plasma jet port 8 and the substrate 2 = 3 to 50 mm, the scanning speed = 50 to 3000 mm / s, the total plasma gas flow rate = 1 to 100 SLM, the H ₂ concentration in Ar + H ₂ gas = 0-10%, shielding gas (N ₂₎ flow rate = 1～100SLM, a value of about RF power = 0.5～10KW appropriate. However, among these quantities, the gas flow rate and power are values per 100 mm of the length of the plasma jet port 8. This is because it is considered appropriate to input parameters proportional to the length of the plasma jet port 8 for parameters such as gas flow rate and electric power.
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.

  Moreover, in this Embodiment, the space 7 inside a long chamber is cyclic | annular. And the clearance gap (dimension g of FIG. 1 (a)) which connects the annular chamber and the plasma jet port 8 as an opening part is 0.5 mm. The effects brought about by such a long chamber structure will be described below.

  Although the internal structure of the plasma torch is not disclosed in detail in Patent Document 6 shown in the conventional example, it is inferred that it is a block of rectangular parallelepiped space like a general cylindrical inductively coupled plasma torch. Is done. When atmospheric pressure inductively coupled plasma is generated in such a space, an annular (doughnut-shaped) plasma is likely to be generated in the chamber.

  That is, since an annular plasma is generated in a rectangular parallelepiped chamber, only a part of the chamber becomes a very high-density plasma, and it is difficult to perform uniform processing in the longitudinal direction. On the other hand, in the present embodiment, since a long annular chamber is formed, a long and narrow plasma P having a racetrack shape is generated along the shape. Therefore, it is possible to perform processing that is much more uniform in the longitudinal direction than in the conventional example. Further, since the volume of the chamber is smaller than that of the conventional example, the high frequency power acting per unit volume is increased, so that there is an advantage that the plasma generation efficiency is improved.

  In addition, it has been pointed out that in a conventional general inductively coupled plasma torch, the discharge becomes unstable when the gas flow rate is increased (for example, Hironobu Yabuta et al., “Design and evaluation of dual int ICP torque”). for low gas consumption ", Journal of Analytical Atomic Spectrometry, 17 (2002) 1090-1095).

  This is presumably because when the annular plasma oscillates in the chamber, the distance between the annular plasma and the coil is too far away in the downstream region of the gas flow, so that inductive coupling cannot be maintained, and the plasma misfires. On the other hand, in the present embodiment, since the gap g of the passage for communicating the annular chamber and the plasma jet port 8 as the opening is extremely narrow as 0.5 mm, the annular plasma P enters the passage. Cannot stay in the annular chamber (region upstream of the passage). Therefore, even if the gas flow rate is increased, the annular plasma P does not fluctuate, and a very stable long annular plasma P is maintained. Therefore, it is possible to generate plasma that is much more stable than the conventional example.

  In addition, when the gap g of the passage connecting the annular chamber and the plasma jet port 8 serving as the opening was examined in detail, it was found that the oscillation of the annular plasma P can be suppressed when g is 1 mm or less. If g is too small, the influence of parts processing and assembly accuracy in the longitudinal direction increases, and the plasma flow that reaches the base material 2 through the passage is weakened. Therefore, it is 0.1 mm or more, preferably 0.3 mm or more. It is desirable to configure.

(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, and is an assembly configuration diagram of an inductively coupled plasma torch unit, in which perspective views of parts (part) are arranged. .

  In FIG. 3, a solenoid coil 3 made of a conductor formed in a cylindrical shape is disposed around a quartz block group in which a second quartz block 5 is inserted into a first quartz block 4. The second quartz block 5 is provided with a plasma gas supply pipe 10. The cross-sectional view of the inductively coupled plasma torch unit is the same as that shown in FIG. That is, since a circular annular chamber is configured, a circular donut-shaped plasma P is generated along the shape. Therefore, since the volume of the chamber is smaller than that of the conventional example, the high frequency power acting per unit volume is increased, so that the plasma generation efficiency is improved.

  Further, since the gap g of the passage for communicating the annular chamber and the plasma jet outlet 8 as the opening portion is extremely narrow as 0.5 mm, the annular plasma P cannot enter the passage, and the annular chamber It stays inside (the area upstream from the passage). Therefore, even if the gas flow rate is increased, the annular plasma P does not fluctuate, and an extremely stable circular annular plasma P is maintained. Therefore, it is possible to generate plasma that is much more stable than the conventional example.

  Although the refrigerant flow path is omitted in FIG. 3, it is possible to adopt the same configuration as that of the first embodiment, or the same as the conventional cylindrical inductively coupled plasma torch. It is also possible to adopt a system in which a single quartz block 4 has a double-pipe structure and a refrigerant flows between them.

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

  FIG. 4A shows the configuration of the plasma processing apparatus according to Embodiment 3 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. FIG. 4B is a cross-sectional view taken along a plane parallel to the longitudinal direction of the inductively coupled plasma torch unit and perpendicular to the substrate. 4A is a cross-sectional view taken along the broken line in FIG. 4B, and FIG. 4B is a cross-sectional view taken along the broken line in FIG.

  In FIG. 4, a quartz tube 16 whose inside constitutes a coolant channel is joined to a first quartz block 4 and a second quartz block 5 by an adhesive 17. A quartz tube 16 is bonded to the outer wall surface of the first quartz block 4, and a quartz tube 16 is bonded to a recess provided in the second quartz block 5. Further, the solenoid coil 3 is joined to the outer wall surface of the first quartz block 4, so that both the solenoid coil 3 itself and the first quartz block 4 can be cooled.

  Further, in the recess of the second quartz block 5, the quartz tube 16 is folded and stored in a wave shape, and the coolant is supplied and drained from above the second quartz block 5, effectively cooling the entire recess. The outer wall surface (the inner wall surface of the long chamber) of the second quartz block 5 in contact with the plasma P can be effectively cooled.

  Further, since the concave portion is formed in the second quartz block 5 from above, two plasma gas manifolds 9 and two plasma gas supply pipes 10 are provided in parallel to the longitudinal direction of the torch unit. Such a configuration also has an advantage that the gas flow rate balance of the two gas supply systems (plasma gas manifold 9 and plasma gas supply pipe 10) can be controlled.

(Embodiment 4)
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG.

  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.

  In the first, second, and third embodiments, the lower part of the first quartz block 4 is squeezed and the plasma flow is guided to the narrow slit-shaped plasma ejection port 8. The second quartz block 5 has two parallel planes that are parallel to the two parallel planes that form the inner wall surface of the annular chamber, and the planes that are connected to the planes and that form the throttle section below the first quartz block 4. Consisted of parts. That is, the space 7 inside the long chamber has a configuration in which the width of the chamber gradually decreases as it approaches the lower side (side closer to the plasma jet port 8).

  In the fourth embodiment, a space 7 inside the long chamber is formed between the groove and the inner wall surface of the first quartz block 4 by forming a groove in the middle portion of the second quartz block 5. ing. That is, the space 7 inside the long chamber has a cross-sectional shape close to a rectangular parallelepiped (the width of the chamber is substantially constant in the vertical direction).

  With such a configuration, there is an advantage that the generation position of the annular plasma P is further stabilized.

  In the following embodiments including the fourth embodiment, description of the refrigerant flow path for cooling the constituent members of the inductively coupled plasma torch unit T is omitted. If necessary, the same configuration as that described in Embodiments 1 and 3 can be adopted as appropriate.

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

  FIG. 6 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 the fifth embodiment, an inner wall surface parallel to the substrate mounting table 1, which is an inner wall surface of the space 7 inside the long chamber, is formed below the first quartz block 4. Moreover, the shape of the 2nd quartz block 5 is comprised in the shape sharpened toward the downward direction so that the width | variety of a block may become narrow gradually as the plasma jet nozzle 8 is approached.

  With such a configuration, the passage for suppressing the intrusion of the annular plasma P is shortened, and a stronger plasma jet can be obtained.

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

  FIG. 7 shows the configuration of the plasma processing apparatus according to Embodiment 6 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 Embodiment 6, in the first quartz block 4 and the second quartz block 5, the portion that becomes the inner wall surface of the space 7 inside the long chamber is configured with a smooth curved surface.

  With such a configuration, the generation position of the annular plasma P is further stabilized, and it is possible to effectively suppress the deterioration of each quartz block from being concentrated on a specific portion.

(Embodiment 7)
The seventh 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 7 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 the seventh embodiment, the lower part of the first quartz block 4 is configured so that the cross-section cut by a plane parallel to the substrate mounting table 1 has the same shape, and inside the second quartz block 5 on the inner side. By forming the groove toward the surface, a space 7 inside the long chamber is formed between the groove and the inner wall surface of the first quartz block 4. That is, the space 7 inside the long chamber has a cross-sectional shape close to a rectangular parallelepiped (the width of the chamber is substantially constant in the vertical direction).

  With such a configuration, there is an advantage that the generation position of the annular plasma P is further stabilized. Moreover, since the width | variety of the plasma jet nozzle 8 is comprised widely, it is a structure advantageous when processing a base material to higher temperature.

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

  FIG. 9 shows the configuration of the plasma processing apparatus according to the eighth embodiment 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 eighth embodiment, the space 7 inside the long chamber is formed between the first quartz block 4 and the second quartz block 5 having a L-shaped cross section and a convex shape facing downward. Is forming. That is, the space 7 inside the long chamber has a cross-sectional shape close to a rectangular parallelepiped (the width of the chamber is substantially constant in the vertical direction).

  With such a configuration, there is an advantage that the generation position of the annular plasma P is further stabilized. In addition, since the width of the plasma jet port 8 is relatively wide, it is an advantageous configuration when it is desired to process the substrate at a higher temperature.

(Embodiment 9)
Embodiment 9 of the present invention will be described below with reference to FIG.

  FIG. 10 shows the configuration of the plasma processing apparatus according to the ninth 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 the ninth embodiment, two plasma gas manifolds 9, plasma gas supply pipes 10 and plasma gas supply holes 11 (through holes) are provided in the second quartz block 5 in parallel to the longitudinal direction of the torch unit. (Plasma gas supply holes 11 are provided with a plurality of round holes in the longitudinal direction).

  In such a configuration, the gas flow rate balance of the two gas supply systems (the plasma gas manifold 9 and the plasma gas supply pipe 10) can be controlled.

  Further, an additional gas manifold 18, an additional gas supply pipe 19 and an additional gas supply hole 20 are provided in the second quartz block 5, and a gas of the same type or a different type from the plasma gas is directed from the plasma jet port 8 to the substrate. Can be supplied.

  With such a configuration, various reactions such as an etching gas, a doping gas, and a deposition gas can be supplied as additional gases to cause various reactions on the substrate surface. When these reactive additional gases are directly supplied to the space 7 inside the long chamber having a high plasma density, the first quartz block 4 and the second quartz block 5 constituting the annular chamber cause severe alteration. In the embodiment, it is possible to effectively promote the reaction of the substrate surface while avoiding such alteration.

(Embodiment 10)
Hereinafter, a tenth embodiment of the present invention will be described with reference to FIG.

  FIG. 11 shows the configuration of the plasma processing apparatus according to the tenth 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 the tenth embodiment, a groove 7 is formed inward in the middle part of the second quartz block 5 so that the space 7 inside the long chamber is formed between the groove and the inner wall surface of the first quartz block 4. The configuration is the same as in the seventh embodiment, except that the groove extends upward from the solenoid coil 3.

  With such a configuration, there is an advantage that ignition of discharge becomes easier.

(Embodiment 11)
Hereinafter, an eleventh embodiment of the present invention will be described with reference to FIG.

  FIG. 12 shows the configuration of the plasma processing apparatus according to the eleventh embodiment 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 eleventh embodiment, the lower part of the second quartz block 5 is configured so that the cross section cut by a plane parallel to the substrate mounting table 1 has the same shape, and the intermediate part of the first quartz block 4 is placed outside. By forming the groove toward the surface, a space 7 inside the long chamber is formed between the groove and the outer wall surface of the second quartz block 5. That is, the space 7 inside the long chamber has a cross-sectional shape close to a rectangular parallelepiped (the width of the chamber is substantially constant in the vertical direction).

  In such a configuration, the plasma flow path from the space 7 inside the long chamber to the plasma ejection port 8 (the gap in the passage connecting the space 7 inside the long chamber and the plasma ejection port 8) can be configured to be short. This has the advantage that the substrate can be irradiated with higher temperature plasma.

  Now, the dimension of the gap in the passage that communicates the long annular chamber and the plasma outlet 8 as the opening has been described in detail in the first embodiment, but other dimensions will be described here.

  If the thickness of the annular chamber (the thickness of a series of closed strings constituting the annular chamber) is d, in FIG. 12, the inner wall surface outside the groove provided in the first quartz block 4 and the first This is expressed as a distance d between the outer wall surface of the two-quartz block 5. If the outer diameter of the annular chamber (the overall size of the annular chamber) is w, in FIG. 12, the distance w between the inner wall surfaces outside the grooves provided in the first quartz block 4 facing each other is shown. expressed. Since the annular chamber is long, the outer diameter w of the annular chamber is different between the long side portion and the short side portion, and the outer diameter w of the annular chamber at the long side portion is smaller.

  When these dimensions d (thickness of the annular chamber) and w (outer diameter of the annular chamber) were examined in detail experimentally, if d was less than 1 mm, high-density thermal plasma was extremely contained in the annular chamber. It has been found that it is less likely to occur. It has also been found that even when w is less than 10 mm, high-density thermal plasma is hardly generated in the annular chamber. From these experiments, it was found that the thickness of the annular chamber is preferably 1 mm or more, and the outer diameter of the annular chamber is preferably 10 mm or more.

  Moreover, since plasma generation efficiency will fall if d is too thick, it is desirable that the thickness d of the annular chamber be 10 mm or less.

(Embodiment 12)
The twelfth embodiment of the present invention will be described below with reference to FIG.

  FIG. 13 shows the configuration of the plasma processing apparatus according to the twelfth 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 the twelfth embodiment, the gap in the passage that connects the space 7 inside the long chamber and the plasma outlet 8 is formed between the lowermost inner wall surface of the first quartz block 4 and the lowermost portion of the second quartz block 5. It is provided between the outer wall surface and is configured so that the length of the gap in the passage communicating the space 7 inside the long chamber and the plasma jet port 8 is extremely short.

  With such a configuration, the substrate can be irradiated with higher temperature plasma. In addition, there is an advantage that the torch unit becomes very small.

(Embodiment 13)
Hereinafter, a thirteenth embodiment of the present invention will be described with reference to FIG.

  FIG. 14 shows the configuration of the plasma processing apparatus according to the thirteenth embodiment 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 thirteenth embodiment, as in the twelfth embodiment, the gap between the passages that connect the space 7 inside the long chamber and the plasma ejection port 8 is formed between the inner wall surface at the bottom of the first quartz block 4 and the second wall. It is provided between the lowermost outer wall surface of the quartz block 5 and is configured so that the length of the gap in the passage that communicates the space 7 inside the long chamber and the plasma outlet 8 is extremely short. Furthermore, instead of the solenoid coil 3, a planar spiral coil 21 is provided above the second quartz block 5.

  With such a configuration, the substrate can be irradiated with higher temperature plasma, and the torch unit becomes very small.

(Embodiment 14)
Hereinafter, a fourteenth embodiment of the present invention will be described with reference to FIG.

  FIG. 15 shows the configuration of the plasma processing apparatus in Embodiment 14 of the present invention, and is a cross-sectional view taken along a plane parallel to the longitudinal direction of the inductively coupled plasma torch unit and perpendicular to the substrate. This corresponds to FIG.

  In the fourteenth embodiment, the passage corresponding to the space 7 inside the long chamber and the plasma jet port 8 is not provided in a portion corresponding to the short side portion of the long chamber. That is, the passage for communicating the annular chamber and the opening is provided in parallel to the longitudinal direction of the opening (not provided in a portion that is not parallel).

  With such a configuration, more efficient plasma generation is possible. In addition, the phenomenon that the plasma flow ejected at both ends of the plasma ejection port 8 becomes excessive can be suppressed with a simple configuration.

  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.

  Moreover, it becomes possible by the various structure of this invention to process the surface vicinity of the base material 2 at high temperature. In particular, it can be applied to the crystallization of TFT semiconductor films and the modification of semiconductor films for solar cells, which have been described in detail in the prior art. It can be applied to various surface treatments such as surface planarization and degassing reduction of a dielectric layer made of aggregates, reflow of various electronic devices, and plasma doping using a solid impurity source. 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 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, 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 efficiently treated in a short time.

  As described above, the present invention can be applied to the crystallization of a TFT semiconductor film and the modification of a solar cell semiconductor film. Of course, cleaning and degassing of the protective layer of the plasma display panel, surface flattening and degassing reduction of the dielectric layer composed of aggregates of silica fine particles, reflow of various electronic devices, plasma doping using a solid impurity source In various surface treatments, plasma is generated stably and efficiently in the vicinity of the surface of the base material for high-temperature heat treatment uniformly for a short time, and the entire desired area of the base material is efficiently processed in a short time. It is an invention useful for processing well.

  In addition, the invention is useful for efficiently treating the entire desired region of the substrate in a short time in low temperature plasma processing such as etching, film formation, doping, and surface modification in the manufacture of various electronic devices. It is.

DESCRIPTION OF SYMBOLS 1 Substrate mounting base 2 Substrate T Inductive coupling type plasma torch unit 3 Solenoid coil 4 First quartz block 5 Second quartz block 7 Space inside long chamber 8 Plasma jet 9 Plasma gas manifold 10 Plasma gas supply pipe 11 Plasma Gas supply hole 13 Shield gas nozzle 14 Shield gas manifold 15 Refrigerant flow path 22 Thin film

Claims (6)

While supplying gas to the first quartz block and a second quartz block enclosed by the ring-shaped chamber,
While spouting gas toward the substrate placed on the substrate mounting table from the long and linear opening that communicates with the annular chamber,
Wherein provided in the vicinity of the annular chamber, and wherein by supplying a high frequency power in the longitudinal direction and the coil oriented parallel to the elongated shape of the opening, to generate a high-frequency electromagnetic field within said annular chamber flop Rasma,
Producing an electronic device by treating the surface of the base material while relatively moving the annular chamber and the base material mounting table in a direction perpendicular to the longitudinal direction of the opening. An electronic device manufacturing method manufactured using the inductively coupled plasma torch .
The method for manufacturing an electronic device according to claim 1, wherein a coolant channel is provided in the dielectric member in parallel to the longitudinal direction of the opening. The method of manufacturing an electronic device according to claim 1, wherein the passage that communicates the annular chamber and the opening includes a gap of 1 mm or less. The method of manufacturing an electronic device according to claim 1, wherein a thickness of the annular chamber is 1 mm or more and 10 mm or less. The method for manufacturing an electronic device according to claim 1, wherein an outer diameter of the annular chamber is 10 mm or more. The method for manufacturing an electronic device according to claim 1, wherein a passage for communicating the annular chamber and the opening is provided in parallel to a longitudinal direction of the opening.

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