JP2011077442A - Plasma processing method and plasma processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma processing method and a plasma processing apparatus, wherein a film of good quality can be obtained by minimizing an impurity concentration of a thin film formed by a microwave plasma processing apparatus including a dielectric for introducing an electromagnetic wave into a processing chamber. <P>SOLUTION: This invention relates to the plasma processing method in which a substrate is stored in the processing chamber, the electromagnetic wave is transmitted from an electromagnetic wave source into the processing chamber through one or two or more dielectrics exposed in the processing chamber, and plasma is excited in the processing chamber to process the substrate. The plasma processing method includes a pre-coating process of coating surfaces of the dielectrics exposed in the processing chamber with films prior to the processing on the substrate. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a plasma processing method and a plasma processing apparatus for generating plasma and forming a film on a substrate.

In the case of using a plasma processing apparatus that performs a plasma CVD (Chemical Vapor Deposition) process and forms a predetermined film on a substrate, an element generated from the inner wall of the processing chamber is released into the processing chamber, and the released element is discharged onto the substrate. It will mix in the film | membrane formed into a film. For this reason, the concentration of impurities contained in the film formed on the substrate becomes high, and the deterioration of the film quality becomes a problem.

  In order to solve the problem of an increase in the impurity concentration in the film, for example, Patent Document 1 discloses a non-single-crystal semiconductor in which a film-forming chamber is covered with an amorphous semiconductor film in a semiconductor structure manufacturing method. A technique for reducing impurities (contaminants) mixed in a film is disclosed. Patent Document 2 discloses a film formation method in which three layers of a silicon nitride film, a non-single crystal silicon film, and a silicon nitride film are sequentially formed on a processing chamber wall in plasma CVD processing to suppress generation of impurities. Is disclosed. Further, Patent Document 3 discloses a technique for covering a processing chamber wall with a film of the same type as a film to be formed on a substrate when forming a semiconductor film.

  On the other hand, the microwave is propagated through a plurality of slots formed on the lower surface of the waveguide and is exposed to the inside of the processing chamber so that the electromagnetic field formed on the surface of the dielectric is generated. There is known a plasma processing apparatus that converts a processing gas supplied into a processing chamber into a plasma by the electric field energy and performs plasma processing on a substrate (see, for example, Patent Document 4).

  Further, as a plasma processing apparatus, a plasma processing apparatus of a type in which a surface wave propagation part that propagates electromagnetic waves along a metal surface exposed inside the processing chamber is provided adjacent to a dielectric disposed on the upper surface of the processing chamber. Is known (see, for example, Patent Document 5).

  Each of the plasma processing apparatuses described in Patent Document 4 and Patent Document 5 has a structure in which a dielectric is disposed on the upper surface of the processing chamber, and the dielectric or a portion adjacent to the dielectric and the dielectric. It is the structure which propagates a microwave. The plasma processing apparatus having such a configuration can uniformly form high-density and low-electron temperature plasma in the processing chamber, and can uniformly and rapidly plasma a large substrate (for example, a semiconductor wafer or a glass substrate). There are advantages.

JP 2004-343039 A JP 2002-158218 A JP 2009-71290 A JP 2007-103519 A WO2008 / 153064A1

  However, when plasma CVD processing is performed using the plasma processing apparatuses of the types described in Patent Document 4 and Patent Document 5, impurities are mixed in the film during film formation, and it is difficult to obtain a high-quality film. There was a problem that there was.

  Therefore, the present invention suppresses the impurity concentration of a thin film formed in a microwave plasma processing apparatus having a dielectric exposed inside the processing chamber in order to transmit electromagnetic waves to the processing chamber, and obtains a high-quality film. A plasma processing method and a plasma processing apparatus are provided.

  According to the present invention, a substrate is stored in a processing chamber, and one or more dielectrics exposed to the inside of the processing chamber are transmitted from an electromagnetic wave source to supply electromagnetic waves into the processing chamber. A plasma processing method for processing a substrate by exciting a plasma to a substrate, comprising: a pre-coating step of coating the surface of the dielectric exposed to the inside of the processing chamber with a film prior to processing of the substrate. Provided.

  According to another aspect of the present invention, a processing chamber for storing a substrate to be plasma processed, an electromagnetic wave source for supplying an electromagnetic wave necessary for exciting the plasma in the processing chamber, and a processing chamber for processing the chamber. A processing gas supply source for supplying a gas; and an apparatus controller for instructing a power setting value for the electromagnetic wave source and for instructing a flow rate setting value for the processing gas supply source. A plasma processing apparatus including one or more dielectrics exposed to the inside of the processing chamber, which is transmitted through the processing chamber, wherein the apparatus controller is exposed to the dielectric of the processing chamber. There is provided a plasma processing apparatus having a storage device storing a procedure of a pre-coating process for coating a film with a film.

  According to the present invention, the impurity concentration of a thin film formed in a microwave plasma processing apparatus having a dielectric exposed inside the processing chamber in order to transmit electromagnetic waves to the processing chamber is suppressed, and a high-quality film is obtained. A plasma processing method and a plasma processing apparatus are provided.

It is the longitudinal cross-sectional view which showed schematic structure of the plasma processing apparatus 1 concerning this Embodiment. 4 is a bottom view of the lid body 3. FIG. 3 is a partially enlarged longitudinal sectional view of a lid body 3. FIG. 3 is an enlarged view of a dielectric 32 as viewed from below the lid 3. FIG. 2 is a longitudinal sectional view showing a schematic configuration of a plasma processing apparatus 110. FIG. It is AA sectional drawing in FIG. 2 is a longitudinal sectional view showing a schematic configuration of a plasma processing apparatus 150. FIG. It is the graph which measured the aluminum concentration contained in the formed microcrystal Si film.

  In the following, a plurality of microwaves are disposed on the upper surface of the processing chamber through a plurality of slots formed on the lower surface of the waveguide for performing CVD processing, which is an example of plasma processing, according to one embodiment of the present invention. A description will be given based on a plasma processing apparatus 1 that propagates to a sheet of dielectric material and converts the processing gas supplied into the processing chamber into plasma by electric field energy in the electromagnetic field formed on the surface of the dielectric material, and applies plasma processing to the substrate. To do. This CVD process can be applied to film formation of microcrystalline silicon as a semiconductor layer of a thin film transistor (TFT) in a liquid crystal display (LCD) device, an organic light emitting diode (OLED) display device, or a light emitting layer in a solar cell, for example. . In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

In the following description, the flow rate will be described using the unit of SCCM. SCCM represents a flow rate normalized at a temperature of 0 ° C. and a pressure of 1 atm, that is, 101325 Pa. For example, xSCCM means that a gas having a mass equal to a gas having a volume of xcc (cc is cm ³ ) is flown per minute at a temperature of 0 ° C. and 1 atm, that is, 101325 Pa.
In the following description, a notation method such as aEb is used for numerical notation. This means a × 10 ^b . For example, 2.7E + 3 means 2.7E + 3 = 2.7 × 10 ⁺³ = 2.7 × 1000.

  FIG. 1 is a longitudinal sectional view showing a schematic configuration of a plasma processing apparatus 1 according to the first embodiment. FIG. 2 is a bottom view of the lid 3 provided in the plasma processing apparatus 1. FIG. 3 is a partially enlarged longitudinal sectional view of the lid 3. The plasma processing apparatus 1 includes a bottomed cubic processing container 2 having an open top, and a lid 3 that closes the upper side of the processing container 2. By closing the upper portion of the processing container 2 with a lid 3, a processing chamber 4, which is a sealed space, is formed inside the processing container 2. The processing container 2 and the lid 3 are made of aluminum, for example, and both are electrically grounded.

  Inside the processing chamber 4 is provided a susceptor 10 as a mounting table for mounting, for example, a glass substrate (hereinafter referred to as “substrate”) G as a substrate. The susceptor 10 is made of, for example, aluminum nitride, and includes a power supply unit 11 for electrostatically adsorbing the substrate G and applying a predetermined bias voltage to the inside of the processing chamber 4, and the substrate G at a predetermined temperature. A heater 12 for heating is provided. A high-frequency power supply 13 for bias application provided outside the processing chamber 4 is connected to the power supply unit 11 via a matching unit 14 including a capacitor, and a high-voltage DC power supply 15 for electrostatic adsorption is connected to a coil. 16 is connected. Similarly, an AC power supply 17 provided outside the processing chamber 4 is connected to the heater 12.

  The susceptor 10 is supported on an elevating plate 20 provided below the processing chamber 4 via a cylindrical body 21 and moves up and down integrally with the elevating plate 20 so that the susceptor in the processing chamber 4 is supported. The height of 10 is adjusted. However, since the bellows 22 is mounted between the bottom surface of the processing container 2 and the elevating plate 20, the airtightness in the processing chamber 4 is maintained.

  An exhaust port 23 for exhausting the atmosphere in the processing chamber 4 by an exhaust device (not shown) such as a vacuum pump provided outside the processing chamber 4 is provided at the bottom of the processing chamber 2. Further, a rectifying plate 24 is provided around the susceptor 10 in the processing chamber 4 for controlling the gas flow in the processing chamber 4 to a preferable state.

  The lid 3 has a configuration in which a slot antenna 31 is integrally formed on the lower surface of the lid body 30, and a plurality of tile-shaped dielectrics 32 are attached to the lower surface of the slot antenna 31. The lid body 30 and the slot antenna 31 are integrally formed of a conductive material such as aluminum and are electrically grounded. As shown in FIG. 1, in the state where the upper portion of the processing container 2 is closed by the lid body 3, an O-ring 33 disposed between the lower peripheral portion of the lid main body 30 and the upper surface of the processing container 2, and slots described later. Airtightness in the processing chamber 4 is maintained by an O-ring (not shown) arranged around 70.

Inside the lid body 30, a plurality of rectangular waveguides 35 having a rectangular cross section are arranged horizontally. In this embodiment, each has six rectangular waveguides 35 extending in a straight line, and the rectangular waveguides 35 are arranged in parallel so as to be parallel to each other. The rectangular waveguides 35 are arranged so that the long side direction of the cross-sectional shape (rectangular shape) is perpendicular to the H plane and the short side direction is horizontal to the E plane. Note that how the long side direction and the short side direction are arranged varies depending on the mode. Each rectangular waveguide 35 is filled with a dielectric member 36 such as fluororesin (for example, Teflon (registered trademark)), alumina (Al ₂ O ₃ ), quartz, or the like.

  As shown in FIG. 2, three microwave supply devices 40 are provided outside the processing chamber 4 in this embodiment, and each microwave supply device 40 has, for example, a microwave of 2.45 GHz. Are introduced into each of the two rectangular waveguides 35 provided inside the lid main body 30. Between each microwave supply device 40 and each of the two rectangular waveguides 35, there are Y branch pipes 41 for distributing and introducing the microwaves to the two rectangular waveguides 35, respectively. Connected. Although the microwave frequency is 2.45 GHz here, the microwave frequency used in the present invention may be 600 MHz to 20 GHz such as 915 MHz, for example.

  As shown in FIG. 1, the upper part of each rectangular waveguide 35 formed inside the lid body 30 is open on the upper surface of the lid body 30, and above each rectangular waveguide 35 thus opened. Therefore, the upper surface 45 is inserted into each rectangular waveguide 35 so as to be movable up and down. On the other hand, the lower surface of each rectangular waveguide 35 formed inside the lid body 30 constitutes a slot antenna 31 formed integrally with the lower surface of the lid body 30. Above the lid body 30, an elevating mechanism 46 that moves the upper surface 45 of the rectangular waveguide 35 up and down relative to the lower surface of the rectangular waveguide 35 (the upper surface of the slot antenna 31) while maintaining a horizontal posture, Each rectangular waveguide 35 is provided.

  As shown in FIG. 3, the upper surface 45 of the rectangular waveguide 35 is disposed in a cover body 50 attached so as to cover the upper surface of the lid body 30. Inside the cover body 50, a space having a height sufficient to raise and lower the upper surface 45 of the rectangular waveguide 35 is formed. On the upper surface of the cover body 50, a pair of guide parts 51 and an elevating part 52 arranged between the guide parts 51 are arranged, and the upper surface 45 of the rectangular waveguide 35 is formed by the guide parts 51 and the elevating part 52. An elevating mechanism 46 that moves up and down is configured.

  An upper surface 45 of the rectangular waveguide 35 is suspended from the upper surface of the cover body 50 via a guide rod 55 provided in each guide portion 51 and an elevating rod 56 provided in the elevating portion 52. Stopper nuts 57 are attached to the lower ends of the guide rod 55 and the lifting rod 56, and these nuts 57 are engaged with holes 58 formed in the upper surface 45 of the rectangular waveguide 35. The upper surface 45 of the rectangular waveguide 35 is supported inside the cover body 50 without dropping.

  The upper ends of the guide rod 55 and the elevating rod 56 penetrate the upper surface of the cover body 50 and protrude upward. The guide rod 55 provided in the guide portion 51 passes through the guide 60 fixed to the upper surface of the cover body 50, and can slide in the guide 60 in the vertical direction. On the other hand, the elevating rod 56 provided in the elevating part 52 passes through a plate 61 supported on the upper surface of the cover body 50 and a rotary handle 62 arranged rotatably on the plate 61. A screw groove is formed on the outer peripheral surface of the elevating rod 56, and the screw groove is engaged with a screw hole formed at the center of the rotary handle 62.

  In such an elevating mechanism 46, when the rotary handle 62 is rotated, the engaging position of the rotary handle 62 with respect to the elevating rod 56 changes, and accordingly, the upper surface 45 of the rectangular waveguide 35 is attached to the cover body 50. It can be moved up and down inside. In this case, the guide rod 55 provided in the guide portion 51 slides in the guide 60 in the vertical direction, so that the upper surface 45 of the rectangular waveguide 35 is always kept in a horizontal posture. The upper surface 45 and the lower surface of the rectangular waveguide 35 (the upper surface of the slot antenna 31) are always parallel.

As described above, since the dielectric member 36 is filled in the rectangular waveguide 35, the upper surface 45 of the rectangular waveguide 35 can be lowered to a position in contact with the upper surface of the dielectric member 36. The rectangular waveguide 35 can be rotated by rotating the rotary handle 62 by moving the upper surface 45 of the rectangular waveguide 35 up and down inside the cover body 50 with the position in contact with the upper surface of the dielectric member 36 as the lower limit. The height h of the upper surface 45 of the rectangular waveguide 35 with respect to the lower surface of 35 (the upper surface of the slot antenna 31) can be arbitrarily changed. Note that the height of the cover body 50 is sufficiently high when the upper surface 45 of the rectangular waveguide 35 is moved up and down according to the conditions of the plasma processing performed in the processing chamber 4 as will be described later. It is set so that it can be moved to.

The upper surface 45 of the rectangular waveguide 35 is made of, for example, a conductive material such as aluminum, and a shield spiral 65 for electrically conducting the lid main body 30 is attached to the peripheral surface portion of the upper surface 45. For example, gold plating is applied to the surface of the shield spiral 65 in order to reduce electric resistance. Therefore, the entire inner wall surface of the rectangular waveguide 35 is formed of conductive members that are electrically connected to each other so that current flows smoothly without discharging along the entire inner wall surface of the rectangular waveguide 35. It is configured.

A plurality of slots 70 as through holes are arranged at equal intervals along the longitudinal direction of each rectangular waveguide 35 on the lower surface of each rectangular waveguide 35 constituting the slot antenna 31. In this embodiment, 13 (equivalent to G5) slots 70 are arranged in series for each rectangular waveguide 35, and the slot antenna 31 as a whole has 13 × 6 rows = 78 locations. The slots 70 are uniformly distributed on the entire lower surface (slot antenna 31) of the lid body 30.

In this way, the slots 70 arranged uniformly distributed throughout the slot antenna 31 are filled with dielectric members 71 such as fluororesin, alumina (Al ₂ O ₃ ), and quartz. A plurality of dielectrics 32 attached to the lower surface of the slot antenna 31 as described above are disposed below the slots 70, respectively. Each dielectric 32 has a rectangular flat plate shape, and is made of, for example, an oxide-based dielectric material such as SiO ₂ , Al ₂ O ₃ , Y ₂ O _3, or a nitride-based dielectric material such as AIN. In the present embodiment, the case where the dielectric 32 is Al ₂ O ₃ (alumina) will be described as an example.

As shown in FIG. 2, each dielectric 32 is disposed so as to straddle two rectangular waveguides 35 connected to one microwave supply device 40 via a Y branch tube 41. . As described above, a total of six rectangular waveguides 35 are arranged in parallel inside the lid body 30, and each dielectric 32 corresponds to two rectangular waveguides 35. Are arranged in three rows.

Further, as described above, twelve slots 70 are arranged in series on the lower surface (slot antenna 31) of each rectangular waveguide 35, and each dielectric 32 has two adjacent ones. The rectangular waveguide 35 (two rectangular waveguides 35 connected to the same microwave supply device 40 via the Y branch pipe 41) is attached so as to straddle between the slots 70. Accordingly, a total of 13 × 3 rows = 39 dielectrics 32 are attached to the lower surface of the slot antenna 31. On the lower surface of the slot antenna 31, a beam 75 formed in a lattice shape is provided to support these 39 dielectrics 32 in a state of being arranged in 13 × 3 rows.

Here, FIG. 4 is an enlarged view of the dielectric 32 viewed from below the lid 3. The beam 75 is disposed so as to surround each dielectric 32, and supports each dielectric 32 in a state of being in close contact with the lower surface of the slot antenna 31. The beam 75 is made of a conductive material such as aluminum and is electrically grounded together with the slot antenna 31 and the lid body 30. The periphery of each dielectric 32 is supported by the beam 75, so that most of the lower surface of each dielectric 32 is exposed in the processing chamber 4.

A space between each dielectric 32 and each slot 70 is sealed using a seal member such as an O-ring (not shown). For example, microwaves are introduced into each rectangular waveguide 35 formed inside the lid body 30 at atmospheric pressure, and thus the gap between each dielectric 32 and each slot 70 is sealed. Since it is stopped, the airtightness in the processing chamber 4 is maintained.

Each dielectric 32 is a rectangle whose length L in the longitudinal direction is longer than the wavelength λg of the microwave propagating in the dielectric and whose length M in the width direction is shorter than the wavelength λg of the microwave propagating in the dielectric. Is formed. For example, when a microwave of 2.45 GHz is generated by the microwave supply device 40, the wavelength λg of the microwave propagating through the dielectric is about 60 mm. For this reason, the length L in the longitudinal direction of each dielectric 32 is set longer than 60 mm, for example, 188 mm. Moreover, the length M in the width direction of each dielectric 32 is shorter than 60 mm, for example, set to 40 mm.

Further, unevenness is formed on the lower surface of each dielectric 32. That is, in this embodiment, seven concave portions 80 are arranged in series along the longitudinal direction on the lower surface of each dielectric 32 formed in a rectangular shape. Each of these recesses 80 has a substantially rectangular shape that is substantially equal in plan view. Moreover, the inner side surface of each recessed part 80 is a substantially vertical wall surface, The depth may be the same respectively, and may differ.

Gas injection ports 85 for supplying a processing gas into the processing chamber 4 around each dielectric 32 are provided on the lower surface of the beam 75 supporting each dielectric 32. The gas injection ports 85 are formed at a plurality of locations so as to surround the periphery of each dielectric 32, so that the gas injection ports 85 are uniformly distributed over the entire upper surface of the processing chamber 4.

As shown in FIG. 1, a gas pipe 90 for supplying a processing gas and a cooling water pipe 91 for supplying cooling water are provided inside the lid main body 30. The gas pipe 90 communicates with each gas injection port 85 provided on the lower surface of the beam 75.

A processing gas supply source 95 disposed outside the processing chamber 4 is connected to the gas pipe 90. In this embodiment, an argon gas supply source 100, a silane gas supply source 101 as a film forming gas, and a hydrogen gas supply source 102 are prepared as a processing gas supply source 95, and valves 100a, 101a, 102a, a mass flow controller 100b, 101b, 102b and valves 100c, 101c, 102c are connected to the gas pipe 90. As a result, the processing gas supplied from the processing gas supply source 95 to the gas pipe 90 is injected into the processing chamber 4 from the gas injection port 85.

In addition, a cleaning gas supply source 96 disposed outside the processing chamber 4 is connected to the gas pipe 90. A cleaning gas such as NF ₃ (nitrogen trifluoride) is supplied from the cleaning gas supply source 96 and is injected into the processing chamber 4 from the gas injection port 85.

The microwave supply source 40, the processing gas supply source 95 and the cleaning gas supply source 96 are connected to the apparatus controller 107. This device controller 107 has a storage device 108, and according to the procedure (sequence) stored in this storage device 108, the set value of the microwave output power for the microwave supply source 40, each mass flow controller In addition, a set value of the flow rate of the gas to flow, an instruction to open / close the valve for each valve, and a set value of the cleaning gas flow rate to the cleaning gas supply source 96 are instructed.

A cooling water supply source 105 disposed outside the processing chamber 4 is connected to the cooling water pipe 91. The cooling water is circulated and supplied from the cooling water supply source 105 to the cooling water pipe 91, so that the lid body 30 is kept at a predetermined temperature.

In the plasma processing apparatus 1 according to the embodiment of the present invention configured as described above, for example, a case where a microcrystalline Si film is formed will be described. First, the cleaning gas is supplied from the cleaning gas supply source 96 to the inside of the processing chamber 4 where the substrate G is not loaded, and the cleaning gas is exhausted from the processing chamber 4 after the cleaning is completed.

Then, after cleaning the inside of the processing chamber 4 and before placing the substrate G in the processing chamber 4, a portion of each dielectric 32 exposed in the processing chamber 4 (the lower surface of each dielectric 32). For example, coating with silicon film or SiO ₂ film (hereinafter referred to as pre-coating) is performed. When performing pre-coating, only silane gas (SiH ₄ ) and argon gas (Ar) are supplied into the processing chamber 4, and hydrogen gas is not supplied. Simultaneously with the supply of the silane gas and the argon gas, exhaust is performed from the exhaust port 23 to bring the inside of the processing chamber 4 to a predetermined pressure, so that the dielectric 32 is precoated. The pre-coating with the silicon-containing film on the portion of each dielectric 32 exposed in the processing chamber 4 is performed under a higher pressure than when the microcrystalline Si film is formed on the substrate G after the pre-coating, Further, it is performed under the condition that the flow rate of SiH ₄ is larger than that during the formation of the microcrystalline Si film on the substrate G, and further under the condition that the microwave power is smaller than that during the formation of the microcrystalline Si film on the substrate G. Done in

  As described above, after pre-coating the portions of each dielectric 32 exposed in the processing chamber 4, a microcrystalline Si film is subsequently formed on the substrate G. When performing the film forming process, the substrate G is placed on the susceptor 10 in the processing chamber 4, and a predetermined processing gas such as argon gas / silane gas is supplied from the processing gas supply source 95 through the gas pipe 90 and the gas injection port 85. While supplying the / hydrogen mixed gas into the processing chamber 4, the gas is exhausted from the exhaust port 23 to set the processing chamber 4 at a predetermined pressure. In this case, the processing gas is evenly supplied to the entire surface of the substrate G placed on the susceptor 10 by ejecting the processing gas from the gas injection ports 85 distributed over the entire lower surface of the lid body 30. Can do. It should be noted that, under conditions where a microcrystalline Si film is formed, a film containing silicon pre-coated on each dielectric 32 may be scraped, so that, for example, 15 to 20 substrates G are formed. It is preferable that the cleaning process is performed each time, and then the pre-coating of the dielectric 32 is repeatedly performed.

Then, while supplying the processing gas into the processing chamber 4 in this way, the substrate G is heated to a predetermined temperature by the heater 12. Further, for example, a 2.45 GHz microwave generated by the microwave supply device 40 shown in FIG. 2 is introduced into each rectangular waveguide 35 via the Y branch pipe 41, and each dielectric is passed through each slot 70. Propagates through the body 32. When the microwaves introduced into the rectangular waveguide 35 are propagated from the slots 70 to the dielectrics 32 in this way, if the size of the slots 70 is not sufficient, the microwaves are transferred from the rectangular waveguide 35 to the slots. No longer enters 70. However, in this embodiment, each slot 70 is filled with a dielectric member 71 having a dielectric constant higher than that of air, such as fluorine resin, Al ₂ O ₃ , quartz, or the like. For this reason, even if the slot 70 does not have a sufficient size, the presence of the dielectric member 71 causes a function similar to that of the slot 70 that is apparently large enough to allow microwaves to enter. Will be fulfilled. Thereby, the microwave introduced into the rectangular waveguide 35 can be reliably propagated from each slot 70 to each dielectric 32.

  Thus, an electromagnetic field is formed in the processing chamber 4 on the surface of each dielectric 32 by the microwave energy propagated in each dielectric 32, and the processing gas in the processing chamber 2 is turned into plasma by the electric field energy. Thus, a microcrystalline Si film is formed on the surface of the substrate G. In this case, since the recesses 80 are formed on the lower surface of each dielectric 32, an electric field substantially perpendicular to the inner surface is formed by the microwave energy propagated to the inner surfaces of these recesses 80, and the vicinity thereof. Thus, plasma can be generated efficiently. In addition, plasma generation locations can be stabilized.

  Here, the conditions of such plasma processing performed in the processing chamber 4 (for example, gas type, pressure, power output of the microwave supply device, etc.) are appropriately set depending on the type of processing. Is a mixed gas of argon gas / silane gas / hydrogen as described above, the pressure is 30 mTorr, and the power output of the microwave supply device is 5 kW × 3.

  As a result of intensive studies on the problem of impurity contamination during the formation of a microcrystalline Si film on the substrate, the present inventors have found that the microcrystalline Si film is formed in a microwave plasma processing apparatus having a dielectric on the upper surface of the processing chamber. The cause of the impurities sometimes mixed is that the dielectric material for introducing microwaves provided on the upper surface of the processing chamber is reduced by hydrogen radicals (H radicals) generated on the surface, and is generated from the dielectric material by reduction. It was found that the element was released into the processing chamber and mixed into the microcrystalline Si film formed on the substrate. The specific experiment of the impurity generation source that led to this knowledge is described below.

When the microcrystalline Si film is formed without pre-coating, in order to identify the factors that generate the aluminum (Al) element as an impurity, an experiment for identifying the Al element generation source was performed using the plasma processing apparatus 1. It was. In this experiment, the dielectric, the beam / nozzle, and the stage block (susceptor) in the processing chamber of the plasma processing apparatus 1 are not covered and the case is covered with yttria (Y ₂ O ₃ ) or a heat-resistant polyimide film tape. In each of the experiments 1 to 4 described later, the microcrystalline Si film is formed on the substrate under the microcrystalline Si film forming conditions described later, and the Al concentration contained in the microcrystalline Si film formed on the substrate Was measured using secondary ion mass spectrometry (SIMS). Table 1 is a table showing the presence or absence of coating of each part in Experiments 1 to 4.

(Deposition conditions of microcrystalline Si on the substrate in this experiment)
The microcrystalline Si film formation condition on the substrate in this experiment is that the substrate is placed in the processing chamber, the microwave power is 5 kW × 3, the silane (SiH 4) gas flow rate is 12 SCCM, the hydrogen (H 2) gas flow rate is 12 SCCM, argon ( Ar) A microcrystalline Si film was formed on the substrate at a gas flow rate of 126 SCCM, a pressure of 30 mTorr, a distance (Gap) between the lower surface of the lid in the processing chamber and the substrate of 90 mm, a stage block temperature of 300 ° C.

(Experiment 1)
A microcrystalline Si film was deposited on the substrate according to the deposition conditions of the microcrystalline Si on the substrate without covering any of the dielectric, beam / nozzle, and stage block. The measured value of the aluminum concentration in the microcrystalline Si was 3.2E + 19 [atoms / cm ³ ].

(Experiment 2)
The dielectric is coated with Y ₂ O ₃ , and the beam / nozzle and the stage block are not coated, and a microcrystalline Si film is formed on the substrate according to the microcrystalline Si film forming conditions on the substrate. Filmed. The measured value of the aluminum concentration in the microcrystalline Si was 8.6E + 17 [atoms / cm ³ ].

(Experiment 3)
The dielectric is coated with Y ₂ O ₃ , the beam / nozzle is coated with heat-resistant tape, and the stage block is not coated. A microcrystalline Si film was formed. The measured value of the aluminum concentration in the microcrystalline Si was 9.4E + 17 [atoms / cm ³ ].

(Experiment 4)
With the dielectric coated with Y ₂ O ₃ and the beam / nozzle and stage block coated with heat resistant tape, the microcrystalline Si film on the substrate is formed according to the microcrystalline Si film deposition conditions on the substrate. A film was formed. The measured value of the aluminum concentration in the microcrystalline Si was 5.8E + 17 [atoms / cm ³ ].

FIG. 8 is a graph plotting the values measured by secondary ion mass spectrometry (SIMS) for the aluminum concentration contained in the microcrystalline Si film formed on the substrate in each case of the above-described Experiments 1 to 4. As shown in FIG. 8, the aluminum concentration in Experiment 1 was significantly higher than that in other Experiments 2-4, and there was almost no difference in aluminum concentration between Experiments 2-4. Since the aluminum concentration in Experiment 1 is high, it can be seen that when the coating is not performed, the microcrystalline Si film contains a large amount of aluminum. Further, in Experiments 2 to 4, there is almost no difference in aluminum concentration in each case. This shows that most of the aluminum mixed in the microcrystalline Si film formed on the substrate is generated from the dielectric.

From the above experiment, when each dielectric 32 is made of Al ₂ O ₃ (alumina), when a microcrystalline Si film is formed on the substrate G without coating, the dielectric 32 becomes microcrystalline. The silicon radicals are reduced by hydrogen radicals generated in the processing chamber 4 during the formation of the Si film, and Al elements and O elements generated from the dielectric 32 due to the reduction are released into the processing chamber and deposited on the substrate. It turns out that it mixes in the crystalline Si film, and this deteriorates the quality of the microcrystalline Si film formed on the substrate G.

  In general, in a plasma processing apparatus, for example, inner walls and beams of a processing chamber are also made of a metal containing an aluminum (Al) element. For this reason, there are concerns about the generation of impurities such as Al elements from these inner walls and beams, but from the above experiments, the source of Al elements that are impurities when forming a microcrystalline Si film without pre-coating is In order to reduce the aluminum concentration in the microcrystalline Si film, it was found that it is effective to cover the dielectric. For this reason, the pre-coating with the silicon-containing film in the present embodiment described above is intended to cover the dielectric 32 in particular.

  On the other hand, when the microcrystalline Si film is formed on the substrate G after the pre-coating with the film containing silicon on the dielectric 32 described in the present embodiment, the microcrystalline Si film is being formed. In addition, since the H radicals generated in the processing chamber 4 and the dielectric 32 are not in direct contact, the reduction of the dielectric 32 does not occur. Therefore, an element that becomes an impurity is not generated when mixed into the microcrystalline Si film from the dielectric 32, and a high-quality microcrystalline Si film is formed on the substrate G.

  As mentioned above, although an example of embodiment of this invention was demonstrated, this invention is not limited to the form of illustration. For example, it is preferable that cleaning is performed each time one substrate is processed, and then pre-coating is performed. Further, for example, after a plurality of substrates are processed, cleaning may be performed, and then pre-coating may be performed. In this case, since the time required for cleaning and the time required for pre-coating are not required, the number of substrates processed per hour (per day) can be increased. By performing the cleaning, the pre-coating film applied to the inside of the processing chamber is also removed. Therefore, it is preferable to perform the substrate processing after performing the pre-coating after the cleaning. Further, for example, pre-coating may be performed without performing cleaning after the substrate processing. In this case, since the time required for cleaning is not required, the number of substrates processed per hour (per day) can be increased. This is particularly effective when the pre-coating film is thinned by the substrate treatment but is not so clean. That is, it is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the idea described in the scope of claims, and naturally, the technical scope of the present invention is also possible. It is understood that it belongs to.

  For example, although the plasma processing apparatus 1 has been illustrated and described in the above embodiment, the scope of application of the present invention is not limited to this. In the following, a microwave plasma of a type in which a surface wave propagation part for propagating electromagnetic waves along a metal surface exposed inside the processing chamber is provided adjacent to a dielectric disposed on the upper surface of the processing chamber is used. The plasma processing apparatus 110 will be described with reference to the drawings. In addition, the element which has the function structure similar to the plasma processing apparatus 1 concerning the said embodiment is demonstrated using the same code | symbol. The plasma processing apparatus 110 is different from the plasma processing apparatus 1 according to the above-described embodiment in the configuration inside the processing container 4, and the other components are substantially the same configuration, and thus the description thereof is omitted. .

FIG. 5 is a longitudinal sectional view (cross section along DD′-E′-E in FIG. 6) showing a schematic configuration of the plasma processing apparatus 110. 6 is a cross-sectional view taken along the line AA in FIG. In the plasma processing apparatus 110, eight dielectrics 32 made of alumina (Al ₂ O ₃ ) are attached to the lower surface of the lid 3. Each dielectric 32 has a plate shape that can be regarded as a substantially square. Each dielectric 32 is arranged so that apex angles thereof are adjacent to each other. Further, in the adjacent dielectric bodies 32, the apex angles of the respective dielectric bodies 32 are arranged adjacent to each other on a line L ′ connecting the center points O ′. In this way, the eight dielectrics 32 are adjacent to each other, and the apex angles of the dielectrics 32 are adjacent to each other on the line connecting the center points O ′ between the adjacent dielectrics 32. By arranging in this manner, three square regions S surrounded by four dielectrics 32 are formed on the lower surface of the lid 3.

  A metal electrode 121 is attached to the lower surface of each dielectric 32. The metal electrode 121 is made of a conductive material, such as an aluminum alloy. Similar to the dielectric 32, the metal electrode 121 is also formed in a square plate shape. However, the width N of the metal electrode 121 is slightly shorter than the width L of the dielectric 32. For this reason, when viewed from the inside of the processing container 4, the periphery of the dielectric 32 is exposed around the metal electrode 121 in a state in which a square outline appears. And when it sees from the inside of the processing container 4, the apex angles of the square outline formed by the peripheral part of the dielectric material 32 are arrange | positioned adjacently.

  The dielectric 32 and the metal electrode 121 are attached to the lower surface of the lid 3 by a connection member 122 such as a screw. The metal electrode 121 is electrically connected to the lower surface of the lid 3 via the connection member 122 and is electrically grounded.

  In the plasma processing apparatus 110, the lower surface of the lid 3 is exposed in the processing container 4 in each region S on the lower surface of the lid 3 and the eight dielectric 32 side regions. Moreover, the lower surface of the cover body 3 is configured in a planar shape as a whole. For this reason, the lower surface of the metal electrode 121 is positioned below the lower surface of the lid 3.

  A groove 130 arranged so as to surround the eight dielectric bodies 32 is continuously provided on the lower surface of the lid 3, and in the inner region partitioned by the groove 130, Eight lid body lower surface inner portions 3b are formed. When viewed from the inside of the processing vessel 4, the lid lower surface inner portion 3 b has substantially the same shape as a right-angled isosceles triangle obtained by dividing the metal electrode 121 into two equal parts. In addition, a plurality of gas discharge holes are dispersedly opened in each region S on the lower surface of the lid 3, and a plurality of gas discharge holes are dispersedly opened in each lid lower surface inner portion 3b. In addition, a metal cover 131 is attached to the lid lower surface inner portion 3b. The metal cover 131 is made of a conductive material such as an aluminum alloy.

  In the plasma processing apparatus 110, the microwave propagated from the microwave supply apparatus 134 to each dielectric 32 during the plasma processing is from the periphery of the dielectric 32 exposed on the lower surface of the lid 3 to the lower surface of the metal electrode 121. And propagated along each region S of the lid 3 and the lower surface of each metal cover 131. Also by the plasma processing apparatus 110, plasma is generated by the power of microwaves under uniform conditions on the lower surface of the metal electrode 121, which is a surface wave propagation portion, and on the entire area S of the lid 3 and the lower surface of each metal cover 131. Thus, it is possible to perform a more uniform plasma process on the entire processing surface of the substrate G.

  The present invention is naturally applicable also to the plasma processing apparatus 110 described above, and the microcrystalline Si film on the substrate G is applied after pre-coating the dielectric 32 with a film containing, for example, silicon, as in the above embodiment. In this case, since the H radical generated in the processing chamber 4 and the dielectric 32 are not in direct contact with each other during the formation of the microcrystalline Si film, the reduction of the dielectric 32 does not occur. Therefore, an element that becomes an impurity is not generated when mixed into the microcrystalline Si film from the dielectric 32, and a high-quality microcrystalline Si film is formed on the substrate G.

  In the above embodiment, the case where only one gas pipe for supplying gas to the processing chamber 4 is provided has been described. However, a plurality of gas pipes may be provided. FIG. 7 is a longitudinal sectional view showing a schematic configuration of the plasma processing apparatus 150 when two gas pipes, that is, an upper gas pipe 90a and a lower gas pipe 90b are provided. In the following description, the same components as those in the above embodiment will be described with the same reference numerals.

  As shown in FIG. 7, in the plasma processing apparatus 150, an upper gas pipe 90 a and a lower gas pipe 90 b communicating from a gas supply source 95 are provided so as to pass above the susceptor 10 in the processing chamber 4. The positional relationship between the upper gas pipe 90 a and the lower gas pipe 90 b is such that the upper gas pipe 90 a is close to the dielectric 32 and the lower gas pipe 90 b is close to the susceptor 10. The opening of the upper gas pipe 90a is in the direction of the dielectric 32 (upward), and the opening of the lower gas pipe 90b is in the direction of the susceptor 10 (downward).

  When the plasma processing method according to the present invention is applied to the plasma processing apparatus 150, the argon gas is supplied from the upper gas pipe 90a both when pre-coating and when the film forming process of the substrate G is performed, and the lower gas pipe Silane gas may be supplied from 90b. In addition, argon gas and silane gas are supplied from the upper gas pipe 90a when pre-coating is performed, and no gas is supplied from the lower gas pipe 90b. It is also conceivable to supply silane gas from the lower gas pipe 90b.

Example 1
Below, the Example (Example 1) of the precoat in the plasma processing apparatus 1 is described.
After performing pre-coating under the pre-coating conditions described below using the plasma processing apparatus 1 with no substrate in the processing chamber, the substrate is put into the processing chamber, and the microcrystalline Si film is formed on the substrate under the substrate processing conditions described below. Film formation was performed.
Pre-coating conditions: With no substrate in the processing chamber, microwave power is 2.55 kW × 3, silane (SiH ₄ ) gas flow rate is 100 SCCM, oxygen (O ₂ ) gas flow rate is 625 SCCM, and argon (Ar) gas flow rate is 1500 SCCM. The pressure was 150 mTorr, the distance (Gap) between the lower surface in the processing chamber of the lid body 3 and the upper surface of the stage block on which the substrate to be deposited was placed was 166 mm, the stage block temperature was 300 ° C., and the deposition time was 25 minutes.
The area of the cross section parallel to the mounting surface of the stage of the plasma generation region, since about 2435Cm ^2, microwave power per unit area of the cross section is about 3.14W / cm ^2. Further, since the substrate size is 40 cm × 50 cm, the silane gas flow rate per unit area of the substrate is about 0.05 SCCM / cm ² . The oxygen (O ₂ ) gas flow rate per unit area of the substrate is about 0.313 SCCM / cm ² . The argon (Ar) gas flow rate per unit area of the substrate is about 0.75 SCCM / cm ² .
Substrate processing conditions: The substrate is placed in a processing chamber, the microwave power is 5 kW × 3, the silane (SiH ₄ ) gas flow rate is 12 SCCM, the hydrogen (H ₂ ) gas flow rate is 12 SCCM, the argon (Ar) gas flow rate is 126 SCCM, and the pressure is 30 mTorr, the distance (Gap) between the lower surface in the processing chamber of the lid body 3 and the upper surface of the stage block on which the substrate to be deposited is placed is 90 mm, the stage block temperature is 300 ° C., and the deposition time is the time required for the desired film thickness. A microcrystalline Si film was formed on the substrate.
The microwave power per unit area of the cross section is about 6.16 W / cm ² . Further, since the substrate size is 40 cm × 50 cm, the silane gas flow rate per unit area of the substrate is about 0.006 SCCM / cm ² . The hydrogen (H ₂ ) gas flow rate per unit area of the substrate is about 0.006 SCCM / cm ² . The argon (Ar) gas flow rate per unit area of the substrate is about 0.063 SCCM / cm ² .

(Example 2)
An example (Example 2) of pre-coating in the plasma processing apparatus 1 will be described. After performing pre-coating under the pre-coating conditions described below using the plasma processing apparatus 1 with no substrate in the processing chamber, the substrate is put into the processing chamber, and the microcrystalline Si film is formed on the substrate under the substrate processing conditions described below. Film formation was performed.
Pre-coating conditions: With no substrate in the processing chamber, microwave power is 2 kW × 3, silane (SiH ₄ ) gas flow rate is 400 SCCM, hydrogen (H ₂ ) gas flow rate is 0 SCCM, argon (Ar) gas flow rate is 600 SCCM, pressure 60 mTorr, the distance (Gap) between the lower surface in the processing chamber of the lid body 3 and the upper surface of the stage block on which the substrate to be deposited is placed is 90 mm, the stage block temperature is 300 ° C., and the deposition time is 25 minutes.
The area of the cross section parallel to the mounting surface of the stage of the plasma generation region, since about 2435Cm ^2, microwave power per unit area of the cross section is about 2.46W / cm ^2. Further, since the substrate size is 40 cm × 50 cm, the silane gas flow rate per unit area of the substrate is about 0.2 SCCM / cm ² . The hydrogen (H ₂ ) gas flow rate per unit area of the substrate is 0.0 SCCM / cm ² . The argon (Ar) gas flow rate per unit area of the substrate is about 0.3 SCCM / cm ² .
Substrate processing conditions: the same substrate processing conditions as described in Example 1 above.

(Example 3)
An example (Example 3) of pre-coating in the plasma processing apparatus 110 will be described. After performing pre-coating under the pre-coating conditions described below using the plasma processing apparatus 110 without placing the substrate in the processing chamber, the substrate is put into the processing chamber, and the microcrystalline Si film is formed on the substrate under the substrate processing conditions described below. Film formation was performed.
Pre-coating conditions: microwave power is 1 kW, silane (SiH ₄ ) gas flow rate is 200 sccm, hydrogen (H ₂ ) gas flow rate is 0 sccm, argon (Ar) gas flow rate is 300 sccm, pressure is 30 mTorr, lower surface in the processing chamber of the lid body 3 The distance (Gap) between the upper surface of the stage block on which the substrate to be deposited is placed is 90 mm, the stage block temperature is 300 ° C., and the deposition time is 10 minutes.
The area of the cross section parallel to the mounting surface of the stage of the plasma generation region, since about 1250 cm ^2, the microwave power per unit area is about 0.803W / cm ^2. Further, since the substrate size is 30 cm × 30 cm, the silane gas flow rate per unit area of the substrate is about 0.22 SCCM / cm ² . The hydrogen (H ₂ ) gas flow rate per unit area of the substrate is 0.0 SCCM / cm ² . The argon (Ar) gas flow rate per unit area of the substrate is about 0.33 SCCM / cm ² .
Substrate processing conditions: microwave power is 4 kW, silane (SiH ₄ ) gas flow rate is 12 sccm, hydrogen (H ₂ ) gas flow rate is 12 sccm, argon (Ar) gas flow rate is 126 sccm, pressure is 20 mTorr, and in the processing chamber of the lid 3 The distance (Gap) between the lower surface and the upper surface of the stage block on which the film formation target substrate is placed is 150 mm, the temperature of the stage block is 300 ° C., and the film formation time is set to a desired film thickness.
The microwave power per unit area of the cross section is about 3.21 W / cm ² . Further, since the substrate size is 30 cm × 30 cm, the flow rate of silane gas per unit area of the substrate is about 0.013 SCCM / cm ² . The hydrogen (H ₂ ) gas flow rate per unit area of the substrate is 0.013 SCCM / cm ² . The argon (Ar) gas flow rate per unit area of the substrate is about 0.14 SCCM / cm ² .

(Comparative Example 1)
As Comparative Example 1, a substrate was placed in a processing chamber without performing pre-coating in the plasma processing apparatus 1, and a microcrystalline Si film was formed on the substrate under the substrate processing conditions described below.
Precoat conditions: The treatment chamber was not coated with a precoat or the like.
Substrate processing conditions: The same substrate processing conditions as described in Example 1 were used.

The aluminum concentration in the microcrystalline Si film formed on the substrate in each of Examples 1 and 2 and Comparative Example 1 is shown in Table 2 below.

The measured value of the aluminum concentration in the microcrystalline Si film in Example 1 is 2.7E + 15 atoms / cm ³ , and the measured value of the aluminum concentration in the microcrystalline Si film in the state where the pre-coating is not performed (Comparative Example 1). Was 3.7E + 19 atom / cm ³ and the aluminum concentration in the microcrystalline Si film formed on the substrate by the pre-coating of Example 1 was reduced.

The measured value of the aluminum concentration in the microcrystalline Si film on the substrate in Example 2 is 2.7E + 17 atom / cm ^3, and the aluminum concentration in the state where the pre-coating is not performed (Comparative Example 1) is 3.7E + 19 atom / cm 3. ³ and the aluminum concentration in the microcrystalline Si film formed on the substrate by the precoat of Example 2 was reduced. Further, high concentration oxygen was mixed in the microcrystalline Si film formed on the substrate in Example 1, but oxygen in the microcrystalline Si film formed on the substrate in Example 2 was. The concentration was 1/100 or less of the same concentration in Example 1.

The measured value of the aluminum concentration in the microcrystalline Si film on the substrate in the state where the precoating of Example 3 was performed was 4.0E + 15 atoms / cm ³ .

  The present invention can be applied to a plasma processing method and a plasma processing apparatus for generating plasma and forming a film on a substrate.

G substrate 1, 110, 150 plasma processing apparatus 2 processing container 3 lid 4 processing chamber 10 susceptor 11 power supply unit 12 heater 13 high frequency power supply 14 matching unit 15 high voltage DC power supply 16 coil 17 AC power supply 20 lifting plate 21 cylindrical body 22 bellows DESCRIPTION OF SYMBOLS 23 Exhaust port 24 Rectifying plate 30 Lid body 31 Slot antenna 32 Dielectric 33 O-ring 35 Rectangular waveguide 36 Dielectric member 40 Microwave supply device 41 Y branch pipe 45 Upper surface 46 Lifting mechanism 50 Cover body 51 Guide part 52 Lifting part 55 Guide rod 56 Lift rod 57 Nut 58 Hole 60 Guide 61 Plate 62 Rotation handle 70 Slot 71 Dielectric member 75 Beam 80 Recess 85 Gas injection port 90 Gas pipe 91 Cooling water pipe 95 Process gas supply source 100 Argon gas supply source 101 Silane gas Sources 102 hydrogen gas supply source 105 cooling water supply source 107 device controller 108 storage 121 a metal electrode 122 connecting member 130 a groove 131 metal cover

Claims (20)

A substrate is accommodated in a processing chamber, and one or more dielectrics exposed inside the processing chamber are transmitted from an electromagnetic wave source to supply electromagnetic waves into the processing chamber, and plasma is excited in the processing chamber. A plasma processing method for processing a substrate,
A plasma processing method comprising a pre-coating step of coating a surface of the dielectric exposed to the inside of the processing chamber with a film prior to processing the substrate. The plasma processing method according to claim 1, wherein the electromagnetic wave is a microwave. The plasma processing method according to claim 1 or 2, wherein the source gas in the pre-coating step and the source gas in processing the substrate are the same. The plasma processing method according to claim 1, wherein the processing of the substrate is forming a microcrystalline silicon film on the substrate. The plasma processing method according to claim 4, wherein the dielectric is an oxide-based dielectric material. The plasma processing method according to claim 5, wherein the dielectric is alumina. The plasma processing method according to claim 4, wherein the film covering the surface of the dielectric is a film containing silicon. The plasma processing method according to claim 7, wherein the coating of the dielectric film containing silicon is performed at a pressure higher than that of forming the microcrystalline silicon film on the substrate. The plasma processing method according to claim 7, wherein the coating of the dielectric material containing silicon is performed under a condition in which a flow rate of SiH ₄ is higher than that of forming a microcrystalline silicon film on the substrate. The plasma processing method according to claim 7, wherein the covering of the dielectric with the film containing silicon is performed under a condition in which the microwave power is smaller than that of forming the microcrystalline silicon film on the substrate. The plasma processing method according to claim 1, wherein the gas introduced into the processing chamber in the pre-coating step does not use a gas other than the gas introduced in the step of processing the substrate. A processing chamber for storing a substrate to be plasma-treated; an electromagnetic wave source for supplying an electromagnetic wave necessary for exciting plasma in the processing chamber; a processing gas supply source for supplying a processing gas into the processing chamber; and the electromagnetic wave source An apparatus controller for instructing a power set value for the processing gas and for instructing a flow rate setting value for the processing gas supply source, wherein the electromagnetic wave supplied from the electromagnetic wave source is transmitted through the processing chamber. A plasma processing apparatus comprising one or more dielectrics exposed inside,
The apparatus controller is a plasma processing apparatus having a storage device storing a procedure of a pre-coating process for coating the dielectric exposed inside the processing chamber with a film. The plasma processing apparatus according to claim 12, wherein the electromagnetic wave is a microwave. The plasma processing apparatus according to claim 12 or 13, wherein the plasma treatment on the substrate is a formation of a microcrystalline silicon film on the substrate. The plasma processing apparatus according to claim 14, wherein the dielectric is an oxide-based dielectric material. The plasma processing apparatus according to claim 14, wherein the dielectric is alumina. The plasma processing apparatus according to claim 15, wherein the film covering the dielectric is a film containing silicon. The plasma processing apparatus according to claim 14, wherein the pressure in the procedure stored as the precoat step is set to a pressure higher than that at the time of forming the microcrystalline silicon film on the substrate. The plasma processing apparatus according to claim 14, wherein the flow rate of SiH _{4 in} the procedure stored as the precoat step is set to a flow rate higher than that at the time of forming a microcrystalline silicon film on the substrate. The plasma processing apparatus according to claim 14, wherein the power of the microwave in the procedure stored as the pre-coating process is set to be smaller than that at the time of forming the microcrystalline silicon film on the substrate.

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