KR20070076545A - Plasma processing apparatus and controlling method for plasma processing apparatus - Google Patents

Abstract

A method for fabricating a semiconductor device is provided to improve the production yield of the semiconductor device by allowing a moving speed of an etchant nozzle to be dependent on a film thickness distribution. An insulating film(11) for forming sidewall insulating films of a gate electrode is deposited on a main surface of a semiconductor wafer(1). Then, the treatment for equalizing the film thickness distribution of the insulating film is performed. In this treatment, the semiconductor wafer is fixed onto a spin stage(32) of an etching apparatus(31) and rotated. An etchant(37) is supplied from an etchant nozzle(36) onto the main surface of the rotated semiconductor wafer while the etchant nozzle is moved from the peripheral side of the main surface of the semiconductor wafer to its central side. The moving speed of the etchant nozzle is controlled depending on the film thickness distribution of the insulating film so that the moving speed in a region with a larger rate of film thickness of the insulating film in a radial direction of the semiconductor wafer is smaller than that in a region with a smaller rate of film thickness.

Description

Plasma processing apparatus and control method of plasma processing apparatus {PLASMA PROCESSING APPARATUS AND CONTROLLING METHOD FOR PLASMA PROCESSING APPARATUS}

1 is a longitudinal sectional view of a microwave plasma processing apparatus according to one embodiment;

2 illustrates a chamber ceiling according to one embodiment;

3 is a view for explaining the relationship between the positions of the respective steps and the susceptor in Example 1;

4 is a graph showing the relationship between the pressure P1 of the processing chamber and the pressure P2 of the exhaust chamber according to the gap between the susceptor and the baffle plate;

Fig. 5 is a diagram for explaining the relationship between the position of the susceptor and each process in the first variation of the first embodiment in relation to the thickness of the dielectric required to shift the phase between the power supply waveguide and the microwave half a cycle;

6 is a view for explaining the relationship between the positions of the steps and the susceptor in the second modification of the first embodiment;

7 is an enlarged view of the vicinity of the baffle plate in Modified Example 2 of Example 1;

8 is a diagram for explaining the relationship between the positions of the steps and the susceptor in Example 2. FIG.

Explanation of symbols for the main parts of the drawings

10 chamber 11: susceptor

18: baffle plate 18a, 18b: support mechanism

31: process gas source 35, 60: remote plasma

40 controller 100 microwave plasma processing device

10u: treatment chamber 10d: exhaust chamber

The present invention relates to a plasma processing apparatus for plasma processing a target object and a control method of the plasma processing apparatus. In particular, the present invention relates to the formation of a coating on the inner wall of a chamber.

Background Art Conventionally, various plasma processing apparatuses have been developed for converting a processing gas supplied into a chamber into plasma to plasma-process a substrate. Among these, the microwave plasma CVD apparatus converts the processing gas into plasma by ionizing and dissociating the processing gas by the power of microwaves to form a film on the substrate.

In the process of plasma formation, in the case of forming a SiO _X film such as SiO ₂ , for example, SiH ₄ gas is generally used as the processing gas. When SiH ₄ gas is used for film formation, an SiO _X film is attached to the inner wall of the chamber. The SiO _x film is heated at the time of film formation of the substrate and cooled when conveyed to / from the load lock chamber. When heating and cooling are repeated in this way, distortion occurs between the deposit and the chamber wall part due to the difference in the thermal expansion rate of the deposits on the chamber inner wall and the members constituting the chamber. As a result, when the deposit reaches a certain thickness, the deposit is separated from the chamber wall portion, falls on the substrate as particles, is mixed with the thin film in film formation, and the film quality is degraded.

In order to suppress the generation of such particles, it is necessary to clean the chamber when the deposit reaches a predetermined thickness to remove the SiO _x film adhered to the chamber inner wall or the like. For this reason, the microwave plasma CVD apparatus generates a plasma by supplying a fluorine (F) -based gas (for example, CF ₄ ), which is a cleaning gas, instead of a processing gas during film formation during cleaning. F radicals in the generated plasma attack the SiO _X film attached to the inner wall of the chamber. As a result, Si in the SiO _x film becomes SiF _X (SiF ₁ , SiF ₂ , SiF ₃ , SiF ₄ ) gas and is discharged out of the chamber. O _X left in the SiO _X film reacts with C and is discharged out of the chamber as a gas of CO or CO ₂ .

By the way, the plasma of the F-based gas is used for cleaning the plasma CVD apparatus. Furthermore, the chamber body is made of Al and the ceiling is made of Al ₂ O ₃ . In such a situation, when F ions in the chamber attack Al ₂ O ₃ , the bond between Al-O is broken, and a film such as Al-F is formed in part. Here, the bonding energy of Al-F is 159 kcal / mol, and the bonding state is stable, similar to Al ₂ O ₃ , where the bonding energy of Al-O is 120 kcal / mol. As a result, during cleaning, Al in the chamber body and Al ₂ O ₃ in the ceiling may be fluorinated, and the chamber inner wall and the ceiling may be partially AlF. Further, since the SiF ₄ or F ₂ generated at the time of cleaning it is a stable coupling state, a portion thereof is not taken out from the chamber, which may be physically adsorbed on the inner wall of the chamber.

The partially fluorinated AlF becomes F due to the breakdown of the Al-F bond due to the action of ions at the time of film formation, and is sometimes released into the chamber. In addition, SiF ₄ and F ₂ adsorbed on the inner wall of the chamber are easily detached because the adsorption energy is small. As a result, a problem arises in that the F-based residue existing in the chamber is detached and mixed into the thin film during film formation.

In addition, in order to increase the yield of the product at the time of film formation and to stably manufacture the product, a series of circulations include supply of radicals into the processing chamber, generation of a thin film in the processing chamber, and exhaust of gas out of the processing chamber. It is necessary to make it to a normal state before forming a to-be-processed object. That is, by setting the process conditions before the film formation to the same conditions as the film formation, it is necessary to perform stable film formation without the radicals generated during the process being consumed on the chamber inner wall or the like.

As described above, the elimination of the problem that desorption of F from Al-F or the like on the inner wall of the chamber or the desorption of SiF ₄ or F ₂ from the inner wall of the chamber is a cause of deterioration of the film quality and the process from before film formation From the viewpoint of setting the conditions to the same conditions as the film formation, the same gas supplied as the gas supplied after the cleaning and before the film formation (i.e., the so-called precoat film formation) and at the time of film formation is converted into a plasma, and the chamber is formed by the plasma. The technique of coating an inner wall surface (that is, forming a so-called precoat film) is known widely from the past (for example, refer patent document 1).

(Patent Document 1) Japanese Unexamined Patent Publication No. 11-340149

By the way, the plasma processing apparatus is generally provided with the baffle plate in order to prepare the flow of radicals (henceforth a storage radical) which contributes to film-forming in a chamber in a preferable state. The conductance of the baffle plate is set small (that is, gas hardly flows) in order to give a good plasma treatment to the substrate during film formation. Therefore, at the time of film formation, the process chamber and the exhaust chamber are partitioned by a baffle plate, and the pressure difference between the chambers is large (see Fig. 4A (no gap)). As a result, even at the time of forming the precoat film described above, the pressure difference between the processing chamber and the exhaust chamber remains large.

On the other hand, the deposition rate DR (Deposition Rate) of the film formed on the inner wall of the chamber can be represented by the following equation (1).

Where k is a proportional constant and P is the pressure.

According to FIG. 4A, since the pressure P1 of the processing chamber is higher than the pressure P2 of the exhaust chamber, the film formation speed DR1 of the processing chamber becomes faster than the film formation speed DR2 of the exhaust chamber. As a result, the precoat film formed on the inner wall surface of the processing chamber is thicker than the precoat film formed on the inner wall surface of the exhaust chamber.

In addition, since the gas is actually supplied to the processing chamber and preferentially used in the processing chamber to form the precoat film, the residual amount of gas (radical) flowing toward the exhaust chamber is reduced. In consideration of this, it is considered that the difference between the precoat film of the processing chamber and the exhaust chamber is larger than the theoretical value derived from the equation (1).

As a result, the precoat film formed on the inner wall surface of the exhaust chamber is still thin at the time when the precoat film is formed to a thickness such that no detachment of the F-based residue causing the film quality from the inner wall surface of the processing chamber occurs. Desorption of F-based residues present on the inner wall surface of the exhaust chamber cannot be suppressed. As a result, the problem that the F-type residue detached | emitted from the exhaust chamber during a process process rises to a process chamber, and reduces film quality has arisen.

On the other hand, when the precoat film is formed to a thickness such that the F-based residue does not detach from the inner wall surface of the exhaust chamber, the precoat film on the inner wall surface of the processing chamber becomes thicker than necessary. As a result, since the thickness of the deposit deposited on the inner wall of the chamber at the time of the process reaches the thickness at which the film is peeled off early, the cycle (interval) for cleaning the inside of the chamber is shortened, resulting in lower throughput and lower productivity. It was happening.

In order to solve the said subject, in this invention, the plasma processing apparatus and the control method of a plasma processing apparatus which coat the inner wall of a chamber with a more uniform thickness are provided.

In order to solve the above problems, according to one aspect of the present invention, there is provided a plasma processing apparatus having a chamber partitioned by a mounting table and a baffle plate into a processing chamber for performing plasma processing on a target object and an exhaust chamber for exhausting gas, By controlling at least one of the mounting table or the baffle plate, the opening ratio between the mounting table and the chamber side wall is adjusted so that the pressure of the processing chamber and the pressure of the exhaust chamber are closer when forming a precoat film on the inner wall surface of the chamber. A plasma processing apparatus for changing is provided.

According to this, at least one of the mounting table or the baffle plate is controlled so that the pressure of the processing chamber and the pressure of the exhaust chamber are approximated when the precoat film is formed on the inner wall surface of the chamber. When the pressure difference between the processing chamber and the exhaust chamber is small, the difference between the film formation speed DR1 of the processing chamber and the film formation speed DR2 of the exhaust chamber obtained from Equation 1 is small. Thereby, the storage radical in a process chamber can be made into substantially the same state as the state of the storage radical in an exhaust chamber. As a result, the film thickness of the precoat film formed in the processing chamber and the film thickness of the precoat film formed in the exhaust chamber can be formed more uniformly and the film quality can be formed uniformly. As a result, the precoat film formation time can be significantly shortened, and the cycle until the inside of the chamber can be cleaned can be lengthened. As a result, productivity can be improved by improving throughput.

As an example of controlling the mounting table so that the pressure difference between the processing chamber and the exhaust chamber is small, the baffle plate is fixed to the inner wall of the chamber, and the opening ratio between the mounting table and the chamber sidewall at the time of forming the precoat film is The method of elevating the said mounting base so that it may become larger than an aperture ratio is mentioned.

According to this, the distance between the mounting table and the baffle plate is adjusted to be different from each other during the formation of the precoat film and the process. That is, at the time of a process, the mounting table is raised and lowered so that the space | interval of a mounting table and a baffle plate may become small. Thus, the process chamber is maintained at a pressure consistent with the process conditions. As a result, since the storage radicals are trapped in the processing chamber, the film formation speed is high and uniformity can be formed on the object to be processed. On the other hand, when forming the precoat film, the mounting table is raised and lowered so as to have a space between the mounting table and the baffle plate. As a result, gas easily flows from the processing chamber to the exhaust chamber, and the pressure difference between the processing chamber and the exhaust chamber becomes small. As a result, the storage radicals in the processing chamber can be made almost the same as the state of the storage radicals in the exhaust chamber. As a result, the film thickness of the precoat film of a process chamber and the precoat film of an exhaust chamber can be formed more uniformly, and the film quality can be formed uniformly.

As another example of controlling the mounting table so that the pressure difference between the processing chamber and the exhaust chamber is small, the mounting table is detachably fixed to either the chamber or the mounting table, and the mounting table is used when the object to be treated is subjected to plasma treatment. The baffle plate is fixed to the mounting table during the lifting and lowering, and when the precoat film is formed on the inner wall surface of the chamber, the baffle plate is fixed to the chamber while the mounting table is raised and lowered to the inner wall surface of the chamber. The method of adjusting the space | interval of the said mounting table and said baffle plate so that the said opening ratio at the time of forming a precoat film | membrane becomes larger than the said opening ratio at the time of plasma-processing a to-be-processed object is mentioned.

According to this, in consideration of the positional relationship between the mounting table and the baffle plate affecting the accuracy of the plasma treatment, during the process, the baffle plate is fixed to the mounting table side and raised together with the mounting table to process the baffle plate. Can be moved to the optimal position. That is, by trapping radicals more effectively in the processing chamber by the baffle plate, the film formation rate to the processing target can be increased, and a uniform film can be formed on the processing target. On the other hand, when the precoat film is formed, the baffle plate is fixed to the chamber side to provide a gap between the mounting table and the baffle plate, thereby making the storage radicals in the processing chamber almost the same as those of the storage radicals in the exhaust chamber. In addition, the film formation speed difference between the processing chamber and the exhaust chamber can be reduced, whereby the film thicknesses of the precoat films of the processing chamber and the exhaust chamber can be formed more uniformly and the film quality can be uniformly formed.

As an example of controlling the baffle plate so that the pressure difference between the processing chamber and the exhaust chamber is small, it is a baffle plate having one or more through holes and an opening / closing mechanism for opening and closing the through holes. The method of adjusting the opening degree of the through-hole is mentioned by controlling the opening / closing mechanism of a baffle plate so that an opening ratio may become larger than the said opening ratio at the time of carrying out plasma processing of a to-be-processed object.

According to this, at the time of a process, the opening-closing mechanism is controlled so that the opening degree of the through hole of a baffle plate may become small. As a result, the process chamber is kept at a pressure consistent with the process conditions, and the storage radicals are confined in the process chamber, whereby a film formation rate can be formed quickly and a uniform film can be formed. On the other hand, when the precoat film is formed, the opening and closing mechanism is controlled so that the opening degree of the through hole provided in the baffle plate is increased. Thereby, the pressure difference between a process chamber and an exhaust chamber becomes small, and the storage radical in a process chamber can be made into the state substantially equal to the state of the storage radical in an exhaust chamber. As a result, the film-forming speed difference between a process chamber and an exhaust chamber becomes small, and the film thickness of the precoat film of a process chamber and an exhaust chamber can be formed more uniformly, and the film quality can be formed uniformly.

According to another aspect of the present invention, there is provided a plasma processing apparatus having a chamber divided by a mounting table and a baffle plate into a processing chamber in which plasma processing is performed on a target object and an exhaust chamber in which gas is exhausted. Thereafter, a plasma processing apparatus is provided for supplying radicals (storage radicals) for promoting the formation of a precoat film on the inner wall surface of the chamber to the exhaust chamber.

Generally, the gas for forming the precoat film is supplied to the process chamber, and the storage radicals in the generated plasma are preferentially used to form the precoat film in the process chamber. As a result, the residual amount of gas (storage radicals) flowing in the exhaust chamber is reduced. However, in the present invention, after washing, storage radicals are supplied to the exhaust chamber separately. As a result, the formation of the precoat film in the exhaust chamber is promoted. As a result, the precoat films of the processing chamber and the exhaust chamber can be formed with almost the same film thickness and with a more uniform film quality.

At this time, radicals supplied to the exhaust chamber may be generated by the remote plasma. The radical may be generated by supplying the remote plasma with the same gas as that supplied when the plasma is subjected to the processing target object.

According to this, for example, when the process is a CVD (Chemical Vapor Deposition) process, the gas supplied at the time of forming the precoat film becomes the same as the gas supplied at the time of the process. As a result, the precoat film becomes the same film as the film formed on the substrate. According to this, the process conditions can be set to the same conditions as before the film formation. As a result, since radicals generated at the time of the process are not consumed in the chamber inner wall or the like, more stable and high quality film formation becomes possible.

The plasma processing apparatus may be a microwave plasma processing apparatus in which the processing gas supplied into the chamber is converted into plasma by microwaves passing through the dielectric through the slot, and the plasma processing apparatus is subjected to plasma processing.

In addition, the dielectric of the microwave plasma processing apparatus is composed of a plurality of dielectric parts, each dielectric part is provided with one or two or more slots, the microwaves respectively transmitted through each dielectric part through the one or more slots. The processing gas supplied into the chamber may be converted into plasma to perform plasma processing on the target object.

According to this, slots are provided in each dielectric part, and in addition, since the area of each dielectric part is significantly smaller than in the related art, the surface wave of each dielectric part can be uniformly propagated by transmitting microwaves to each dielectric part. have. As a result, the process window can be widened and plasma processing can be performed with high precision and stability. In addition, since the dielectric window can be configured by each of the smaller and lighter dielectric parts, the microwave plasma processing apparatus can be manufactured easily and at low cost, and it is possible to flexibly cope with the large area of the workpiece.

According to another aspect of the present invention, there is provided, by a mounting table and a baffle plate, a control method of a plasma processing apparatus having a chamber partitioned into a processing chamber for performing plasma processing on a target object and an exhaust chamber for exhausting gas. The plasma processing apparatus for elevating the mounting table to a predetermined position when performing plasma treatment, and elevating the mounting table to a predetermined position to provide a gap between the mounting table and the baffle plate during or after the chamber is cleaned. A control method of is provided.

According to this, during the process, the mounting table is raised and lowered to a predetermined position, thereby maintaining the processing chamber at a pressure consistent with the process conditions and confining storage radicals in the processing chamber, whereby the film formation speed is high and a uniform film is formed. Can be formed. On the other hand, during or after the chamber is cleaned, the pressure difference between the processing chamber and the exhaust chamber can be reduced by providing a space between the mounting table and the baffle plate by lifting the mounting table. As a result, the storage radicals in the processing chamber are made almost the same as those of the storage radicals in the exhaust chamber, and the film thickness difference between the processing chamber and the exhaust chamber is reduced, thereby making the film thicknesses of the precoat films of the processing chamber and the exhaust chamber more uniform. The film quality can be formed uniformly. As a result, not only can the precoat film formation time be significantly shortened, but the cycle until the inside of the chamber is cleaned can be lengthened. As a result, productivity can be improved by improving throughput.

In addition, according to another aspect of the present invention, a baffle plate having a one or more through holes and an opening / closing mechanism for opening and closing the through holes and an exhaust table for exhausting gas and a processing chamber for performing a plasma treatment on the object to be processed. A control method of a plasma processing apparatus having a chamber partitioned into chambers, the method comprising: sliding the opening and closing mechanism to a predetermined position when plasma processing a target object, and forming a precoat film on the inner wall surface of the chamber during or after the chamber is cleaned. The control method of the plasma processing apparatus which slides the said opening / closing mechanism to a predetermined position so that opening degree of the said through hole at the time of making it larger than opening degree of the said through hole at the time of carrying out plasma processing of a to-be-processed object is provided.

According to this, during the process, by controlling the opening / closing mechanism so that the opening degree of the through hole of the baffle plate becomes small, the process chamber is maintained at a pressure consistent with the process conditions and the storage radicals are trapped in the process chamber, whereby the deposition rate is increased. It is possible to form a fast and uniform film. On the other hand, when the precoat film is formed, the opening / closing mechanism is controlled to increase the opening degree of the through hole provided in the baffle plate, thereby reducing the pressure difference between the processing chamber and the exhaust chamber, thereby reducing the storage radicals in the processing chamber and By making it almost the same and making the film-forming speed difference of each chamber small, the film thickness of the precoat film of a process chamber and an exhaust chamber can be formed more uniformly, and the film quality can be formed uniformly.

According to another aspect of the present invention, there is provided a control method of a plasma processing apparatus having a chamber divided by a mounting table and a baffle plate into a processing chamber for performing plasma processing on a target object and an exhaust chamber for exhausting gas. After cleaning, the control method of the plasma processing apparatus which supplies the radical which promotes formation of the precoat film | membrane to the inner wall surface of the said chamber is provided.

According to this, the formation of the precoat film in the exhaust chamber is promoted by the radicals supplied to the exhaust chamber after cleaning. Thereby, the precoat film of a process chamber and an exhaust chamber can be formed in substantially uniform thickness with more uniform film quality.

EMBODIMENT OF THE INVENTION Preferred embodiment of this invention is described in detail, referring an accompanying drawing below. In addition, in this specification and drawing, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol about the component which has a substantially same functional structure.

In addition, the specification will be 1mTorr ^{(10 -3 × 101325/760)} Pa, 1sccm is ^{(10 -6 / 60) ㎥ /} sec.

(Example 1)

(Configuration of Microwave Plasma Processing Apparatus)

First, with respect to the configuration of the microwave plasma processing apparatus according to the first embodiment of the present invention, Fig. 1, which is a cross-sectional view of the apparatus cut in the longitudinal direction (the direction perpendicular to the y axis), and the ceiling surface of the processing chamber of the apparatus are shown. It demonstrates, referring FIG. 2 shown. In addition, in the following description, the gate oxide film formation process using the microwave plasma processing apparatus which concerns on a present Example is demonstrated as an example.

The microwave plasma processing apparatus 100 has a housing composed of a chamber 10 and a lid 20. The chamber 10 has a bottomed cuboid cuboid shape with its top open and is grounded. The chamber 10 is formed of metal, such as aluminum (Al), for example.

Inside the chamber 10, a susceptor 11 (mounting table) for mounting a target object such as a substrate G is provided at a substantially center. The susceptor 11 is made of aluminum nitride, for example.

Inside the susceptor 11, a power feeding portion 11a and a heater 11b are provided. The high frequency power supply 12b is connected to the power feeding portion 11a via a matching unit 12a (for example, a capacitor). Moreover, the high voltage | voltage DC power supply 13b is connected to the electric power feeding part 11a via the coil 13a. The matching unit 12a, the high frequency power supply 12b, the coil 13a, and the high voltage direct current power supply 13b are provided outside the chamber 10, and the high frequency power supply 12b and the high voltage direct current power supply 13b are grounded. .

The power feeding portion 11a is configured to apply a predetermined bias voltage to the inside of the chamber 10 by the high frequency power output from the high frequency power supply 12b. Moreover, the power supply part 11a is made to electrostatically adsorb | suck the board | substrate G by the DC voltage output from the high voltage | voltage DC power supply 13b.

An AC power supply 14 provided outside the chamber 10 is connected to the heater 11b, and the substrate G is maintained at a predetermined temperature by an AC voltage output from the AC power supply 14.

The bottom surface of the chamber 10 is opened in a cylindrical shape, and one end of the bellows 15 is mounted to the outer wall surface of the chamber 10 near the opened outer circumference. The elevating plate 16 is fixed to the other end of the bellows 15. In this way, the opening part of the bottom surface of the chamber 10 is sealed by the bellows 15 and the lifting plate 16.

Moreover, the susceptor 11 is supported by the housing 17 arrange | positioned on the lifting plate 16, and is integrated with the lifting plate 16 and the housing 17 by the drive force output from the electric motor 16a. Ascend to the enemy. In this way, the electric motor 16a adjusts the susceptor 11 to a desired height.

In the periphery of the susceptor 11, the baffle plate 18 for controlling the flow of the gas in the chamber 10 to a preferable state is provided. The interior of the chamber 10 is divided by the susceptor 11 and the baffle plate 18 into a processing chamber 10u for plasma processing the substrate G and an exhaust chamber 10d for exhausting the gas. Moreover, the support mechanism 18a which protruded toward the susceptor 11 in the center is provided in the inner wall side part of the chamber 10 substantially. The baffle plate 18 is fixed to the inner wall side of the chamber 10 by being supported by the support mechanism 18a at the edge of the lower surface.

The chamber 10 is provided with a dry pump 19a, an APC (Automatic Pressure Control) 19b and a TMP (Turbo Molecular Pump) 19c as the exhaust mechanism 19. .

The dry pump 19a opens and closes a predetermined valve, removes gas until the inside of the chamber 10 reaches a predetermined depressurization state, and then switches the opening and closing of the valve to reduce the back pressure of the TMP 19c. The APC 19b is provided with a valve that controls the communication state between the exhaust chamber 10d and the TMP 19c, and slides the valve of the APC 19b according to the change of the pressure P1 in the processing chamber 10u, thereby exhausting the exhaust chamber. The communicating part of 10d and TMP 19c is made into the desired opening degree. As a result, the atmosphere in the chamber 10 is reduced to a predetermined vacuum degree in accordance with the opening degree of the valve of the APC 19b.

The lid 20 is arranged to seal the top of the chamber 10. Like the chamber 10, the lid 20 is made of a metal which is a nonmagnetic material such as aluminum (Al). The lid 20 includes a dielectric composed of a lid body 21, waveguides 22a to 22f, slot antennas 23a to slot antennas 23f, dielectric parts 24a to dielectric parts 24f, And a beam 25 is provided.

The chamber 10 and the lid 20 are fixed by an O-ring 26 disposed between the bottom edge of the lid body 21 and the top edge of the chamber 10, thereby maintaining airtightness in the chamber. have.

The waveguides 22a to 22f formed on the lower surface of the lid main body 21 are arranged in parallel with each other in the y-axis direction as shown in FIG. 2. The waveguide 22a, the waveguide 22b, the waveguide 22c, the waveguide 22d, the waveguide 22e and the waveguide 22f have a branch waveguide 27a and a branch waveguide (V-shaped in plan view at the end thereof). 27b) and branch waveguide 27c are connected to each other. A microwave generator 28 is connected to each branch waveguide 27.

Each waveguide 22 is formed by a rectangular waveguide having a rectangular cross section perpendicular to the respective axial directions. For example, in the TE10 mode (TE wave: transverse electric wave: a wave whose magnetic field has a component of the direction of microwave propagation), the pipe wall in the longitudinal direction of the cross section perpendicular to the axial direction of each waveguide 22 has an H plane parallel to the magnetic field. The pipe wall in the short side direction becomes E plane parallel to the electric field. How to arrange the long side direction and the short side direction of each waveguide is changed by the mode (electromagnetic field distribution in a waveguide). The inside of each waveguide 22 and each branch waveguide 27 is filled with a dielectric member such as alumina (aluminum oxide: Al ₂ O ₃ ), quartz, or a fluororesin. By the dielectric member, the tube wavelength λg ₁ of each waveguide 22 is controlled in accordance with the expression λg ₁ = λc / (εε ₁ ) ^1/2 . Is the wavelength of free space, and ε ₁ is the dielectric constant of the dielectric member.

As shown in FIG. 1, slot antenna 23a-slot antenna 23f is provided in the bottom surface of waveguide 22a-waveguide 22f, respectively. In each slot antenna 23, as shown in FIG. 2, thirteen slots 23a are provided as transmission holes, respectively.

The slots 23a of the respective slot antennas 23 are arranged at equal intervals of, for example, λg / 2. In this way, 78 slots (= 13 x 6) are arranged in the ceiling of the chamber 10.

On the lower surface of the slot antenna 23, 39 dielectric parts 24 which form a rectangular flat plate shape are arrange | positioned. Each dielectric part 24 is made of, for example, quartz glass, aluminum nitride (AlN), alumina (aluminum oxide: Al ₂ O ₃ ), sapphire, SiN, ceramic, or the like so as to transmit microwaves.

As shown in Fig. 2, the beam 25 is formed in a lattice shape and supports 39 dielectric parts 24 on the lower surface of the slot antenna 23. The girders 25 are conductors made of a metal which is a nonmagnetic material such as aluminum, and are grounded through the slot antenna 23, the lid body 21, and the chamber 10 shown in FIG. A plurality of gas introduction pipes 29 pass through the respective girders 25, and a processing gas is injected from the injection hole 30 (see FIG. 2) at the tip of the gas introduction pipe 29.

The process gas supply source 31 of FIG. 1 is a valve (valve 31a1, valve 31a3, valve 31b1, valve 31b3, valve 31b5, valve 31b7, valve 31c1, valve 31c3). )), Mass flow controller (mass flow controller 31a2, mass flow controller 31b2, mass flow controller 31b6, mass flow controller 31c2) and gas source (O ₂ gas source 31a4, SiH ₄ and consists of a gas supply source (31b4), Ar gas supply source (31b8), CF ₄ gas supply source (31c4)).

The processing gas supply source 31 is configured to selectively supply each processing gas into the chamber 10 by controlling the opening and closing of each valve. In addition, each mass flow controller adjusts the processing gas to a desired concentration by controlling the flow rate of the processing gas supplied by each mass flow controller.

For example, in the process, the O ₂ gas is supplied from the O ₂ gas supply source 31a4 and injected into the processing chamber 10u through the gas flow path 32a. In addition, SiH ₄ gas and Ar gas are supplied from the SiH ₄ gas supply source 31b4 and the Ar gas supply source 31b8, respectively, and are injected into the processing chamber 10u through the gas flow path 32b.

Further, for example, at the time of washing, O ₂ gas and CF ₄ gas is O ₂ are respectively supplied from a gas supply source (31a4), and CF ₄ gas supply source (31c4), through the gas flow channel (32a) is injected into the processing chamber (10u) .

Outside of the microwave plasma processing apparatus 100, a remote plasma 35 is provided. The remote plasma 35 has a processing container 35a, a coil 35b, a high frequency power supply 35c, a capacitor C, and a carrier tube 35d, and is used to clean the inside of the chamber 10.

The processing container 35a is constituted by a hollow tubular member, and is formed of a dielectric. In the outer periphery of the processing container 35a, the coil 35b is wound in a spiral shape. The high frequency power supply 35c is connected to one end of the coil 35b, and the other end is grounded. The high frequency power supply 35c is connected with a capacitor C for insulating a direct current component.

As the cleaning gas, for example, CF ₄ gas, O ₂ gas, and Ar gas are supplied to the processing container 35a from the processing gas supply source 31. As another example of the cleaning gas, an NF ₃ gas and an Ar gas may be supplied. When the high frequency power output from the high frequency power supply 35c is applied to the coil 35b, a high frequency magnetic field is generated around the coil 35b. The cleaning gas is converted into plasma in the processing container 35a by an induction electric field induced by the temporal change of the magnetic field. In the inductively coupled plasma (ICP) generated in this way, the lifetime of radicals is long. As a result, only active F radicals are supplied to the processing chamber 10u via the transfer pipe 35d.

In addition, a cooling water supply source 33 is disposed outside the microwave plasma processing apparatus 100. The cooling water supply source 33 cools the inside of the lid body 21 by circulating and supplying the cooling water to the water channel 34 provided in the lid body 21.

In addition, the controller 40 is provided outside the microwave plasma processing apparatus 100. The controller 40 is configured to output drive signals to the electric motor 16a and the APC 19b at predetermined timings, respectively. The first pressure sensor 41 connected to the controller 40 is provided in the processing chamber 10u and detects the pressure P1 of the processing chamber 10u. Similarly, the second pressure sensor 42 connected to the controller 40 is provided in the exhaust chamber 10d to detect the pressure P2 of the exhaust chamber 10d.

With this configuration, the microwaves output from the microwave generator 28 shown in FIG. 2 propagate each waveguide 22, pass through each dielectric part 24 through each slot, and enter the process chamber 10u. In this way, the film-forming gas supplied from the process gas supply source 31 turns into plasma by the electric field energy of the microwave which entered into the process chamber 10u, and the gate oxide film is formed in the board | substrate G. In addition, when the reaction products deposited on the inner wall of the chamber have a predetermined thickness by performing the film formation process on the plurality of substrates G, the processing gas supply source 31 and the remote plasma 35 use the F-based gas as the cleaning gas. The chamber inner wall is cleaned by the action of F radicals in the plasma generated from the cleaning gas. After the cleaning, the deposition gas is again supplied from the processing gas supply source 31, and the same precoat film as the gate oxide film is formed on the inner wall of the chamber under the same process conditions as the film formation. When the precoat film has a certain thickness, the substrate G is loaded again, and the film forming process is resumed.

(Lowing operation of the susceptor 11)

Next, the susceptor shown in FIG. 3 in each of the processes (1) film formation (gate oxide film formation), (2) cleaning, and (3) F-based gas reduction film formation (precoat film formation) described above. The elevating operation of (11) will be described while showing the results of the inventors and the like actually experimenting.

The process conditions set by each inventor in each process at the time of experiment are as follows.

(1) Process conditions during film formation (gate oxide film formation)

The process conditions at this time were 200 mTorr in the pressure of the processing chamber 10u, and the power of the microwave was 2.55 Pa 3 (using three microwave generators 28). As the gas type, Ar gas, SiH ₄ gas and O ₂ gas were used, and the amount of gas was 1500 sccm for Ar gas, 150 sccm for SiH ₄ gas, and 950 sccm for O ₂ gas. In addition, the temperature of the board | substrate G was 300 degreeC. The distance between the substrate G and the dielectric parts 24 was 166 mm.

(2) Process conditions at the time of washing

In the above description, CF ₄ gas, O ₂ gas and Ar gas are exemplified as the cleaning gas, but in the experiment, NF ₃ gas and Ar gas were used as the F-based gas. That gas was Ar gas 1000sccm, NF ₃ gas 1000sccm. Moreover, the pressure of the processing chamber 10u was 2 Torr, and the output from the high frequency power supply 35c was 10.8 kPa. The distance between the substrate G and the dielectric parts 24 was 194 mm.

(3) The process conditions at the time of precoat film formation were made the same conditions as the film formation.

(1) the tabernacle

Before the process of forming the gate oxide film is started, the controller 40 transmits a drive signal to the electric motor 16a for raising and lowering the susceptor 11 to a predetermined height determined by process conditions. In response to the drive signal, the susceptor 11 rises to a predetermined height by the power output from the electric motor 16a (upper part in FIG. 3).

In this state, the controller 40 transmits a drive signal to the processing gas supply source 31 to supply the deposition gas, whereby the processing gas supply source 31 supplies Ar gas, SiH ₄ gas, and O ₂ gas to the processing chamber 10u. Supply in. These deposition gases are converted into plasma by microwaves.

In a state where the susceptor 11 is raised to a predetermined height, there is almost no gap between the susceptor 11 and the baffle plate 18. In addition, the APC 19b is controlled to open the valve. Thereby, the process chamber 10u can be maintained at the pressure (about 50 mTorr-about 500 mTorr) matched with process conditions. As a result, the storage radicals in the plasma generated from the film forming gas are confined in the processing chamber 10u, whereby the film forming speed is high and uniformity can be formed on the substrate G.

(2) cleaning

When the reaction product deposited on the inner wall of the chamber reaches a predetermined thickness by repeating the processes of forming the gate oxide films on the plurality of substrates G, respectively, the inside of the chamber is cleaned. At that time, the controller 40 transmits a drive signal for providing a gap between the susceptor 11 and the baffle plate 18 to the electric motor 16a. In response to the drive signal, the susceptor 11 descends to a predetermined height by the power output from the electric motor 16a (lower part in FIG. 3). In this state, a predetermined interval (interval S) is generated between the susceptor 11 and the baffle plate 18. For this reason, gas flows easily from the processing chamber 10u to the exhaust chamber 10d, and the difference between the pressure P1 of the processing chamber 10u and the pressure P2 of the exhaust chamber 10d becomes small.

For example, at the time of film formation, when the pressure P1 of the processing chamber 10u is 500 mTorr as shown by the line (A) of FIG. 4, the pressure P2 of the exhaust chamber 10d is 250 mTorr, and the pressure P1 of the processing chamber 10u is exhausted. It turns out that it is higher than the pressure P2 of the chamber 10d.

On the other hand, when the susceptor 11 is dropped so that the gap S becomes 1 cm during washing, as shown by the line (B) of FIG. 4, when the pressure P1 of the processing chamber 10u is 500 mTorr, the exhaust chamber 10d It is understood that the pressure P2 of) is 480 mTorr, and the pressure P1 of the processing chamber 10u and the pressure P2 of the exhaust chamber 10d are very small.

In this state, the controller 40 transmits a drive signal to the processing gas supply source 31 to supply the cleaning gas, so that the processing gas supply source 31 supplies the NF ₃ gas and the Ar gas into the processing chamber 10u. These cleaning gases are converted into plasma by microwaves.

In addition, by the drive signal, the process gas supply source 31 supplies the NF ₃ gas and the Ar gas to the remote plasma 35. The remote plasma 35 converts these cleaning gases into plasma and supplies F radicals into the exhaust chamber 10d. Specifically, cleaning gases NF ₃ and Ar are supplied to the processing container 35a, and the high frequency power of the high frequency power supply 35c is applied to the coil 35b. As a result, the gas is converted into plasma by a high frequency electric field induced from a high frequency magnetic field generated around the coil 35b, and since only the F radicals in the plasma have a long life, the gas flows into the chamber through the conveyance pipe 35d until the end. Supplied. The supplied F radical attacks the SiO _X film attached to the inner wall of the chamber and is discharged out of the chamber as SiF _X (SiF ₁ , SiF ₂ , SiF ₃ , SiF ₄ ) gas. In addition, the remaining O _X reacts with N in the NF ₃ gas supplied to the processing chamber 10u, and is discharged out of the chamber as gas such as NO or NO ₂ .

As described above, at the time of washing, the susceptor 11 is positioned downward, so that gas easily flows from the processing chamber 10u to the exhaust chamber 10d, so that the pressure P1 of the processing chamber 10u and the exhaust chamber 10d are maintained. The difference between the pressures P2 is decreasing. According to the above equation (1), the pressure difference between the chambers is made small, and the F radicals in the processing chamber 10u are made almost the same as the F radicals in the exhaust chamber 10d, thereby eliminating the difference in the cleaning speeds of the chambers. Can be. As a result, the generation rates of the SiF _X gas and the gases such as NO and NO ₂ are almost the same in the processing chamber 10u and the exhaust chamber 10d. As a result, the inner walls of the processing chamber 10u and the exhaust chamber 10d can be cleaned more uniformly, and the cleaning time can be significantly shortened.

By the way, the plasma of the F-based gas is used for cleaning the microwave plasma processing apparatus 100. Furthermore, the chamber body is made of Al, and the ceiling is made of Al ₂ O ₃ . In such a situation, when F ions attack Al ₂ O ₃ , the bond between Al-O is broken, and a film such as Al-F is formed in part. In addition, the bonding energy of Al-F is 159 kcal / mol, and the bonding state is stable, similar to Al ₂ O ₃ , in which the bonding energy of Al-O is 120 kcal / mol. As a result, during cleaning, Al in the chamber body and Al ₂ O ₃ in the ceiling may be fluorinated, and the chamber inner wall and the ceiling may be partially AlF.

Further, since the SiF ₄ or F ₂ generated at the time of cleaning it is a stable coupling state, a portion thereof is not discharged out of the chamber, which may be physically adsorbed on the inner wall of the chamber. In this way, the adsorbed SiF ₄ or F ₂ is easily detached because the adsorption energy is small. Further, as described above, AlF partially fluorinated on the inner wall of the chamber becomes F when the Al-F bond is broken by ions at the time of film formation, and is released into the chamber. In this way, a problem arises in that the F-based residue present in the chamber is detached and mixed into the thin film during film formation.

In addition to this, in order to increase the yield of the product at the time of film formation and to stably manufacture the product, the supply of radicals into the chamber 10 and the thin film in the chamber 10 before forming the object to be processed. It is necessary to bring a series of circulation, called generation and exhaust of the gas out of the chamber 10, into a steady state. That is, by setting the process conditions in the chamber before the film formation to the same conditions as the film formation, it is necessary to perform stable film formation without the radicals generated during the process being consumed on the chamber inner wall or the like.

As described above, the problem that desorption of F from Al-F or the like on the inner wall of the chamber or the desorption of SiF ₄ or F ₂ from the inner wall of the chamber is the cause of deterioration of the film quality, and at the same time, the process from before film formation From the viewpoint of setting the conditions to the same conditions as at the time of film formation, before the film formation (before forming the precoat film), a gas such as a gas supplied at the time of film formation is converted into plasma, and the plasma inner wall surface is formed by the plasma. It coats (namely, forms a so-called precoat film). The lifting operation of the susceptor 11 at the time of forming the precoat film will be described next.

(3) precoat film formation

In forming the precoat film, the inner wall surface of the chamber is coated with the same SiO ₂ film (gate oxide film) as in the process treatment. At this time, a predetermined interval (interval S) has occurred between the susceptor 11 and the baffle plate 18. For this reason, in the chamber, a state in which gas easily flows from the processing chamber 10u to the exhaust chamber 10d is maintained, and the difference between the pressure P1 of the processing chamber 10u and the pressure P2 of the exhaust chamber 10d is small. to be.

In this state, the controller 40 transmits a drive signal to the processing gas supply source 31 to supply gas for forming the precoat film, whereby the processing gas supply source 31 is again an Ar gas which is a gas such as a deposition gas. , SiH ₄ gas and O ₂ gas are supplied into the processing chamber 10u. These deposition gases are converted into plasma by microwaves.

As described above, according to Equation 1, the pressure difference between the chambers is reduced, and the storage radicals in the processing chamber 10u are made to be substantially the same as the storage radicals in the exhaust chamber 10d. You can get rid of the difference in speed. As a result, the film thickness of the precoat film of the process chamber 10u and the exhaust chamber 10d can be formed more uniformly, and the film quality can be formed uniformly, and the time for forming the precoat film to a predetermined thickness is greatly increased. It can be shortened.

As described above, in the present embodiment, the gap S is provided between the susceptor 11 and the baffle plate 18 at the time of cleaning and at the time of forming the precoat film. Thereby, the chamber inner wall can be cleaned more uniformly, and the film thickness of the precoat film can be formed more uniformly and the film quality can be formed uniformly. As a result, cleaning time and precoat film formation time can be shortened significantly, throughput can be improved, and productivity can be improved.

In addition, at the time of film formation, the baffle plate 18 is raised so that a gap is hardly generated between the baffle plate 18 and the susceptor 11. As a result, since the distribution of the storage radicals in the processing chamber 10u can be made uniform, a good gate oxide film can be formed on the substrate G.

(Modification 1 of Example 1)

Next, the structure and operation of the microwave plasma processing apparatus 100 according to the first modification of the first embodiment will be described with reference to FIG. 5. In this apparatus, a supporting mechanism for supporting the baffle plate 18 is also disposed in the side wall portion of the susceptor 11, and the baffle plate 18 is either the inner wall side of the chamber 10 or the side wall portion of the susceptor. The baffle plate 18 is different from the microwave plasma processing apparatus of the first embodiment in which the baffle plate 18 is fixed to the inner wall side of the chamber 10 in that it is detachably fixed thereto. Therefore, the above explanation will focus on this difference.

On the inner wall side part of the chamber 10, the support mechanism 18a which protrudes toward the susceptor 11 from the substantially center is attached. Moreover, the supporting mechanism 18b which protruded toward the side wall of the chamber 10 is also attached in the substantially center of the side surface of the susceptor 11. The baffle plate 18 is detachably fixed to either the chamber 10 or the susceptor 11 according to the height of the susceptor 11.

Next, the lifting operation of the susceptor 11 in the case of this modification is demonstrated.

(1) the tabernacle

At the time of film formation, the controller 40 transmits a drive signal to the electric motor 16a, and the susceptor 11 rises to a predetermined height by operating the electric motor 16a in accordance with this drive signal. While ascending, the baffle plate 18 is fixed to the side wall of the susceptor 11 by being supported by the support mechanism 18b at its inner bottom edge, and rises to the predetermined height with the susceptor 11. (Upper part of Figure 5).

In this state, there is almost no gap between the susceptor 11 and the baffle plate 18. Therefore, the pressure P1 of the processing chamber 10u is maintained in a state consistent with the process conditions. As a result, since the storage radicals are confined in the processing chamber, a SiO ₂ film having a high deposition rate and high uniformity is formed on the substrate G.

(2) cleaning

When the reaction product deposited on the chamber inner wall reaches a predetermined thickness, the controller 40 transmits a drive signal to the electric motor 16a, and the susceptor 11 is operated by the electric motor 16a operating in accordance with this drive signal. It descends to a predetermined height (lower part in FIG. 5). While descending, when the baffle plate 18 fixed to the susceptor 11 descends to a height at which the support mechanism 18a on the chamber 10 side is provided, the baffle plate 18 is formed at the outer edge of the lower surface thereof. It engages with the support mechanism 18a. Thereafter, when the susceptor 11 is further lowered, the baffle plate 18 leaves the support mechanism 18b on the susceptor 11 side and is fixed to the support mechanism 18a on the inner wall side of the chamber 10. Only the susceptor 11 descends to a predetermined height.

In this state, when the cleaning gas is supplied, a predetermined interval (interval S) is generated between the susceptor 11 and the baffle plate 18, so that the pressure P1 of the processing chamber 10u and the exhaust chamber 10d The difference of the pressure P2 becomes small, and the difference in the washing | cleaning speed of each chamber can be eliminated by making the storage radical of the process chamber 10u into substantially the same state as the storage radical of the exhaust chamber 10d. As a result, the generation rates of the SiF _X gas and the gases such as NO and NO ₂ are almost the same in the processing chamber 10u and the exhaust chamber 10d. As a result, similarly to the first embodiment, the inner walls of the processing chamber 10u and the exhaust chamber 10d can be cleaned more evenly, and the cleaning time can be significantly shortened.

(3) precoat film formation

At the time of forming the precoat film, the height of the susceptor 11 is intact, and therefore the difference between the pressure P1 of the processing chamber 10u and the pressure P2 of the exhaust chamber 10d is small. In this state, when the gas for forming the precoat film is supplied as in the case of Example 1, the generated storage radicals become almost the same in the processing chamber 10u and the exhaust chamber 10d, and the film forming speed of each chamber is maintained. The car is almost gone. As a result, the film thickness of the precoat film of the process chamber 10u and the exhaust chamber 10d can be formed more uniformly, and the film quality can be formed uniformly, and the time for forming the precoat film to a predetermined thickness is greatly increased. It can be shortened.

Thus, in this modification, the baffle plate 18 is fixed to the chamber wall surface side at the time of washing | cleaning and the precoat film formation. In this way, by providing a gap S between the susceptor 11 and the baffle plate 18 and making the state of the storage radicals almost the same, the inner wall of the chamber can be cleaned more evenly, and the film thickness of the precoat film is increased. The film quality can be formed more uniformly. As a result, cleaning time and precoat film formation time can be shortened significantly. As a result, productivity can be improved by improving throughput.

On the other hand, in this modification, the baffle plate 18 is fixed to the susceptor 11 side during film formation. As a result, the baffle plate 18 can be raised together with the susceptor 11. The positional relationship between the stage on which the substrate G is mounted and the baffle plate 18 greatly affects the film quality of the SiO ₂ film. Therefore, as in the present modification, by moving the baffle plate 18 together with the susceptor 11 to an optimal position, a high quality gate oxide film can be formed by the substrate G.

(Modification 2 of Example 1)

Next, the structure and operation of the microwave plasma processing apparatus 100 according to the second modification of the first embodiment will be described with reference to FIG. 6. The baffle plate 18 which concerns on this modification is provided with the opening-and-closing mechanism which opens and closes one or more through-holes, and the through-holes, The susceptor (point) is controlled by this opening / closing mechanism. It is different from the microwave plasma processing apparatus 100 of Example 1 which adjusts the clearance gap S of the susceptor 11 and the baffle plate 18 by elevating 11). Therefore, the above explanation will focus on this difference.

As shown in FIG. 7, which is an enlarged view of the portion indicated by XP in FIG. 6, the baffle plate 18 includes a baffle plate body 18c having one or more through holes (only the through holes 18c1 are shown in the drawing). It has the opening-closing mechanism 18d which opens and closes the through hole 18c1.

The baffle plate main body 18c is supported by the supporting mechanism 18b attached to the center of the side of the susceptor 11, and is fixed to the center of the side wall of the susceptor 11 at the inner edge of the lower surface thereof. The opening and closing mechanism 18d has the same shape as the baffle plate main body 18c, has the same shape of the through hole at the same position as the through hole of the baffle plate main body 18c, and adheres to the upper surface of the baffle plate main body 18c. It is provided. As for the opening / closing mechanism 18d, the screw bone is processed by the power transmission member 50 in the outer peripheral part side wall. The power transmission member 50 is connected to the electric motor 51 through the side wall of the chamber 10. As the outer wall of the chamber 10, the boundary with the power transmission member 50 is sealed by the O-ring 52, whereby the airtightness in the chamber 10 is maintained.

The power of the electric motor 51 is transmitted to the opening-closing mechanism 18d via the power transmission member 50, and the opening-closing mechanism 18d slides in the left-right direction by this. If the opening / closing mechanism 18d slides in this way, the position of the through-hole 18c1 of the baffle plate main body 18c and the through-hole 18d1 of the opening-closing mechanism 18d will shift | deviate. In this way, the opening ratio between the susceptor 11 and the side wall of the chamber 10 is controlled by adjusting the gap (opening area S of the through hole 18c1 and the through hole 18d1).

Next, the lifting operation of the susceptor 11 according to the present modification will be described with reference to FIG. 6.

(1) the tabernacle

At the time of film formation, the controller 40 transmits a drive signal to the electric motor 16a. By the power output from the electric motor 16a in response to this drive signal, the opening / closing mechanism 18d slides by a predetermined amount (upper part in FIG. 6). Thereby, the opening area S of the through hole 18c1 and the through hole 18d1 which penetrates the baffle plate 18 becomes small. As a result, the pressure P1 of the processing chamber 10u is maintained at a value consistent with the process conditions. As a result, since the storage radicals are confined in the processing chamber, it is possible to form a film on the substrate G with a high film formation rate and high uniformity.

(2) cleaning

When the reaction product deposited on the inner wall of the chamber has a predetermined thickness, the controller 40 transmits a drive signal to the electric motor 16a. By the power output from the electric motor 16a in response to this drive signal, the opening / closing mechanism 18d slides in a direction opposite to that at the time of film formation by a predetermined amount (lower part in FIG. 6). Thereby, the opening area S of the through hole 18c1 and the through hole 18d1 which penetrates the baffle plate 18 becomes large. In this way, the difference in the pressure P1 of the process chamber 10u and the pressure P2 of the exhaust chamber 10d can be made small by increasing the opening ratio between the susceptor 11 and the baffle plate 18 at the time of washing | cleaning. In this state, the cleaning gas is supplied into the chamber, and the chamber inner wall is cleaned. As a result, the inner walls of the processing chamber 10u and the exhaust chamber 10d can be cleaned more uniformly, and the cleaning time can be significantly shortened.

(3) precoat film formation

At the time of forming the precoat film, the film forming gas is supplied with the position of the opening / closing mechanism 18d intact. Thereby, the state of a storage radical can be made substantially the same in process chamber 10u and exhaust chamber 10d. As a result, the film thickness of the precoat film | membrane of the process chamber 10u and the exhaust chamber 10d can be formed more uniformly, and the film quality can be formed uniformly. As a result, the time for forming the precoat film up to a predetermined thickness can be significantly shortened.

As described above, in the present modification, by controlling the opening / closing mechanism 18d of the baffle plate 18, one or two or more through holes so that the opening ratio at the time of cleaning and at the time of forming the precoat film becomes larger than the opening ratio at the time of film formation. To adjust the opening degree. Thereby, the difference between the pressure P1 of the process chamber 10u and the pressure P2 of the exhaust chamber 10d can be made small. As a result, the difference in the film-forming speed of each chamber can be eliminated by making the state of a storage radical nearly the same in the process chamber 10u and the exhaust chamber 10d. Thereby, the film thickness of the precoat film | membrane of the process chamber 10u and the exhaust chamber 10d can be formed more uniformly, and the film quality can be formed uniformly. On the other hand, at the time of film formation, the opening area S of the through hole 18c1 and the through hole 18d1 penetrating the baffle plate 18 is made small, thereby confining the storage radicals in the processing chamber, whereby the film forming speed is high, Uniform film formation can be performed on the substrate G.

(Example 2)

Next, the configuration and operation of the microwave plasma processing apparatus 100 according to the second embodiment will be described with reference to FIG. 8. In this apparatus, in addition to the processing gas supply source 31 for supplying the processing gas for film formation and the remote plasma 35 for supplying the cleaning gas (all of which are omitted in FIG. 8, see FIG. 1), the exhaust chamber 10d is freed. Since it has the remote plasma 60 which supplies the gas for coat film formation, it is different from the microwave plasma processing apparatus of Example 1 which does not have the remote plasma 60 in the exhaust chamber 10d side. In addition, in this embodiment, the susceptor 11 is not raised or lowered from the first embodiment in which the susceptor 11 is elevated. Therefore, the above explanation will focus on this difference.

The remote plasma 60 provided outside the microwave plasma processing apparatus 100 has a processing container 60a, a coil 60b, a high frequency power supply 60c, a capacitor C, and a conveying pipe 60d, and the chamber 10. It is used when forming a precoat film in the inside.

In the processing container 60a, a gas (here, SiH ₄ gas, O ₂ gas, Ar gas), which is the same as the processing gas when the substrate G is plasma-treated as the gas for forming the precoat film from the gas supply source, is the processing gas supply source. It is supplied from 31. When the high frequency power output from the high frequency power supply 60c is applied to the coil 60b, a high frequency magnetic field is generated around the coil 60b. The gas becomes plasma in the processing container 60a by an induction electric field induced by the temporal change of the magnetic field. In the inductively coupled plasma generated in this way, the lifetime of radicals is long. As a result, only active storage radicals are supplied to the processing chamber 10u via the conveyance pipe 60d.

Next, the operation of the remote plasma 60 according to the present embodiment will be described with reference to FIG. 8.

(1) During film formation and cleaning

At the time of film formation and cleaning, the controller 40 does not transmit a drive signal to the remote plasma 60. Therefore, the remote plasma 60 does not operate during film formation and cleaning (upper part in FIG. 8). Therefore, at the time of film formation, the film forming gas is supplied to the processing chamber 10u from the processing gas supply source 31 shown in FIG. 1, and the film forming process is performed on the substrate G. FIG. At the time of cleaning, the cleaning gas is supplied from the processing gas supply source 31 and the remote plasma 35 to the processing chamber 10u to clean the inside of the chamber 10.

(2) pre-coat film formation

In forming the precoat film, SiH ₄ gas, O ₂ gas, and Ar gas are supplied from the processing gas supply source 31 to the processing chamber 10u. The supplied gas is converted into plasma by the electric field energy of the microwaves transmitted through the dielectric parts 24, whereby a gate oxide film as a precoat film is formed in the chamber 10.

Usually, since the gas supplied to the processing chamber 10u is used preferentially for film formation of the processing chamber 10u, the residual amount of gas (storage radicals) flowing in the exhaust chamber 10d is reduced. In addition, there is almost no gap S between the baffle plate 18 and the susceptor 11. In this case, the pressure difference between the processing chamber 10u partitioned by the baffle plate 18 and the exhaust chamber 10d becomes large, and the storage radicals are confined in the processing chamber 10u, and therefore, from the processing chamber 10u to the exhaust chamber 10d. Very little storage radicals flow in. As a result, the precoat film of the exhaust chamber 10d becomes very thin as compared with the precoat film of the processing chamber 10u.

However, in this embodiment, the remote plasma 60 supplies the storage radicals to the exhaust chamber 10d. Specifically, first, the controller 40 transmits a drive signal to the high frequency power supply 60c. The high frequency power supply 60c supplies high frequency power to the coil 60b in accordance with this drive signal (lower part in FIG. 8).

When the high frequency power is applied to the coil 60b, a high frequency magnetic field is generated around the coil 60b, and the gas in the processing container 60a is converted into plasma by the energy of the high frequency electric field induced by the magnetic field. In the inductively coupled plasma generated in this way, the lifetime of radicals is long. As a result, only active storage radicals are supplied to the processing chamber 10u via the conveyance pipe 60d.

According to this, even if the residual amount of storage radicals flowing from the processing chamber 10u to the exhaust chamber 10d is small, the formation of the precoat film on the inner wall surface of the exhaust chamber 10d is prevented by the storage radicals supplied from the remote plasma 60. Is promoted. As a result, even if the susceptor 11 is not elevated, the film thickness of the precoat film of the processing chamber 10u and the precoat film of the exhaust chamber 10d can be formed more uniformly and the film quality can be formed uniformly.

As described above, according to each embodiment, a precoat film having a uniform film quality and substantially the same film thickness can be formed in a shorter time by the inner wall of the processing chamber 10u and the inner wall of the exhaust chamber 10d. Thereby, since the time until the thickness of the deposit deposited on the chamber inner wall reaches the thickness at which the film is peeled off during the process becomes longer, the cycle for cleaning the inside of the chamber can be lengthened. As a result, productivity can be improved by improving throughput.

In each embodiment, the opening ratio between the susceptor 11 and the inner sidewalls of the chamber 10 is preferably 1.4%.

In addition, in the modification 1 of Example 1 and Example 1, the drive signal for lowering the susceptor 11 to the predetermined position was output at the time of washing | cleaning. However, the controller 40 may output the drive signal when the precoat film is formed instead of during the cleaning. According to this, the susceptor 11 is lowered to a predetermined position when the precoat film is formed.

Similarly, in the modification 2 of Example 1, the drive signal for sliding the opening-closing mechanism 18d to the predetermined position was output at the time of washing | cleaning. However, the controller 40 may output the drive signal at the time of forming the precoat film. According to this, at the time of forming the precoat film, the opening ratio is controlled to be large.

In each of the above embodiments, as the cleaning gas, not only F-based cleaning gases such as NF ₃ , SF ₆ and CF ₄ , but also chlorine-based cleaning gases such as Cl and Cl ₂ may be used.

In each of the above embodiments, a method of generating plasma by a remote plasma was used to generate F radicals at the time of washing and storage radicals at the time of forming the precoat film. However, the generation method of each radical is not limited to this, For example, it can also generate | occur | produce by supplying energy, such as heat, light, and a radiation.

In the cleaning, the processing gas supply source 31 and the remote plasma 35 may be used in combination, only the remote plasma 35 may be used, and only the processing gas supply source 31 may be used.

In the above embodiment, the operations of the respective parts are related to each other, and can be replaced as a series of operations in consideration of the correlation with each other. By substituting in this way, the embodiment of the microwave plasma processing apparatus 100 can be made into the embodiment of the method of controlling the microwave plasma processing apparatus 100.

As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. Those skilled in the art can clearly think of various changes or modifications within the scope described in the claims, and they are naturally understood to belong to the technical scope of the present invention.

For example, the plasma processing apparatus according to the present invention is not limited to the microwave plasma processing apparatus, and may be an inductively coupled plasma processing apparatus or a capacitively coupled plasma processing apparatus.

In addition, the plasma processing apparatus according to the present invention may be a microwave plasma processing apparatus having a plurality of tile-like dielectrics, or may be a microwave plasma processing apparatus having a large area dielectric which is not divided into tile-like dielectrics.

In addition, in the plasma processing apparatus according to the present invention, not only the CVD process but also all processes executable by the generated plasma, such as an ashing process and an etching process, can be performed.

As explained above, according to this invention, the plasma processing apparatus which coats the inner wall surface of a chamber with a more uniform thickness, and the control method of the plasma processing apparatus can be provided.

INDUSTRIAL APPLICABILITY The present invention is applicable to a plasma processing apparatus for coating an inner wall of a chamber to a more uniform thickness and a method for controlling the plasma processing apparatus.

Claims (12)

A plasma processing apparatus having a chamber partitioned by a mounting table and a baffle plate into a processing chamber for performing plasma processing on a target object and an exhaust chamber for exhausting gas, By controlling at least one of the mounting table or the baffle plate, the opening ratio between the mounting table and the chamber side wall is adjusted so that the pressure of the processing chamber and the pressure of the exhaust chamber are closer when forming a precoat film on the inner wall surface of the chamber. Plasma processing apparatus for changing. The method of claim 1, The baffle plate is fixed to the inner wall of the chamber, Plasma processing for adjusting the distance between the mounting table and the baffle plate so that the opening ratio when the precoat film is formed on the inner wall surface of the chamber becomes larger than the opening ratio when the target object is subjected to plasma treatment by elevating the mounting table. Device. The method of claim 1, The baffle plate is detachably fixed to any one of the chamber or the mounting table, The baffle plate is fixed to the mounting table when the object is plasma-lifted, and the baffle plate is lifted up and down while the mounting table is formed when a precoat film is formed on the inner wall surface of the chamber. And adjusting the gap between the mounting table and the baffle plate so that the opening ratio at the time of forming the precoat film on the inner wall surface of the chamber is larger than the opening ratio at the time of plasma treatment of the object. The method according to any one of claims 1 to 3, The baffle plate has one or more through holes and an opening and closing mechanism for opening and closing the through holes, By controlling the opening / closing mechanism of the baffle plate, the opening degree of the one or more through holes so that the opening ratio when the precoat film is formed on the inner wall surface of the chamber is larger than the opening ratio when the object to be processed is subjected to plasma treatment. Plasma processing apparatus for adjusting the. A plasma processing apparatus having a chamber partitioned by a mounting table and a baffle plate into a processing chamber for performing plasma processing on a target object and an exhaust chamber for exhausting gas, And, after cleaning the chamber, supplying radicals that promote the formation of a precoat film to the inner wall surface of the chamber to the exhaust chamber. The method of claim 5, And said radicals are generated by a remote plasma. The method of claim 6, And the radicals are generated by supplying the remote plasma with the same gas as that supplied when the plasma processing is performed on the target object. The method according to any one of claims 1, 2, 3, 5, 6, and 7, The plasma processing apparatus is a plasma processing apparatus which is a microwave plasma processing apparatus which converts a processing gas supplied into the chamber by microwaves that have passed through a dielectric through a slot and performs plasma processing on a target object. The method of claim 8, The dielectric is composed of a plurality of dielectric parts, each dielectric part is provided with one or two or more slots, and is supplied into the chamber by microwaves that respectively transmit each dielectric part through the one or more slots. Plasma processing apparatus which plasma-processes a process gas and performs a plasma process to a to-be-processed object. A control method of a plasma processing apparatus having a chamber partitioned by a mounting table and a baffle plate into a processing chamber for performing plasma processing on a target object and an exhaust chamber for exhausting gas, When the object to be processed is subjected to plasma treatment, the mounting table is lifted to a predetermined position, The control method of the plasma processing apparatus which raises and lowers the said mounting stand to a predetermined position in order to space the said mounting table and the said baffle plate at the time of the chamber cleaning or after cleaning. A plasma processing apparatus having a chamber partitioned by a baffle plate having one or more through holes and an opening / closing mechanism for opening and closing the through holes, and a processing chamber for performing plasma processing on the object to be processed and an exhaust chamber for exhausting gas. As a control method, When plasma processing a target object, the said opening / closing mechanism is slid to a predetermined position, At the time of cleaning the chamber or after cleaning, the opening degree of the through hole when the precoat film is formed on the inner wall surface of the chamber is set to a predetermined position for increasing the opening degree of the through hole when the object to be treated is plasma-treated. The control method of the plasma processing apparatus which slides an opening / closing mechanism. A control method of a plasma processing apparatus having a chamber partitioned by a mounting table and a baffle plate into a processing chamber for performing plasma processing on a target object and an exhaust chamber for exhausting gas, And cleaning the chamber, and supplying radicals to promote formation of a precoat film on the inner wall surface of the chamber.

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