JP4107736B2 - Plasma processing apparatus and plasma processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma processing apparatus that performs processing such as etching, ashing, or CVD on an object to be processed using plasma in the manufacture of a semiconductor element substrate, a glass substrate for a display, and the like, and to plasma the object to be processed using the apparatus. It relates to a method of processing.
[0002]
[Prior art]
Plasma generated by applying energy to the reaction gas from the outside is widely used in manufacturing processes such as LSI or LCD. In particular, the use of plasma is an indispensable basic technology in the dry etching process.
[0003]
FIG. 8 is a side sectional view showing a microwave plasma processing apparatus of the same type as the apparatus disclosed in Japanese Patent Laid-Open No. 62-5600, and FIG. 9 is a plan view of the microwave plasma processing apparatus shown in FIG. is there. The rectangular box-shaped reactor 41 is entirely made of aluminum. The upper opening of the reactor 41 is hermetically sealed with a sealing plate 44. The sealing plate 44 is formed of a dielectric material such as quartz glass or alumina, which has heat resistance and microwave transparency and has a low dielectric loss.
[0004]
A rectangular box-shaped cover member 50 that covers the upper portion of the reactor 41 is connected to the reactor 41. A dielectric line 54 is attached to the ceiling portion in the cover member 50, and an air gap 53 is formed between the dielectric line 54 and the sealing plate 44. The dielectric line 54 is formed by molding a dielectric material such as Teflon (registered trademark) such as fluororesin, polyethylene resin, or polystyrene resin into a plate shape having a convex portion at the apex of a substantially pentagon that combines a rectangle and a triangle. The convex portion is fitted in a waveguide 29 connected to the peripheral surface of the cover member 50. A microwave oscillator 30 is connected to the waveguide 29, and the microwave oscillated by the microwave oscillator 30 is incident on the convex portion of the dielectric line 54 by the waveguide 29.
[0005]
As described above, the base end side of the convex portion of the dielectric line 54 is a tapered portion 54a having a substantially triangular shape in plan view, and the microwave incident on the convex portion has a width along the tapered portion 54a. It spreads in the direction and propagates throughout the dielectric line 54. The microwave is reflected by the end face of the cover member 50 facing the waveguide 29, and the incident wave and the reflected wave are superimposed to form a standing wave in the dielectric line 54.
[0006]
The inside of the reactor 41 is a processing chamber 42, and a required gas is introduced into the processing chamber 42 from a gas introduction pipe 45 fitted in a through hole penetrating the peripheral wall of the processing chamber 42. In the center of the bottom wall of the processing chamber 42, a mounting table 43 for mounting the sample W is provided, and a high-frequency power supply 47 is connected to the mounting table 43 via a matching box 46. Further, an exhaust port 48 is formed in the bottom wall of the reactor 41, and the inside air of the processing chamber 42 is discharged from the exhaust port 48.
[0007]
In order to perform the etching process on the surface of the sample W using such a microwave plasma processing apparatus, the processing chamber 42 is evacuated from the exhaust port 48 to a desired pressure, and then the processing chamber 42 is connected to the processing chamber 42 through the gas introduction pipe 45. The reaction gas is supplied into 42. Next, microwaves are oscillated from the microwave oscillator 30 and introduced into the dielectric line 54 via the waveguide 29. At this time, the microwave is uniformly spread in the dielectric line 54 by the tapered portion 54 a, and a standing wave is formed in the dielectric line 54.
[0008]
Due to this standing wave, a leakage electric field is formed below the dielectric line 54, which is introduced into the processing chamber 42 through the air gap 53 and the sealing plate 44. In this way, the microwave propagates into the processing chamber 42. Thereby, plasma is generated in the processing chamber 42, and the surface of the sample W is etched by the plasma. As a result, even if the processing chamber 42 is enlarged to process the large-diameter sample W, microwaves can be uniformly introduced into the entire region of the processing chamber 42, and the large-diameter sample W can be uniformly plasma-treated. can do.
[0009]
[Problems to be solved by the invention]
In the conventional plasma processing apparatus, in order to spread the microwaves uniformly on the dielectric line 54, a taper part 54a protruding in the horizontal direction from the edge of the sealing plate 44 and the reactor 41 is provided. The size of the tapered portion 54a is determined according to the area of the rectangular portion of the dielectric line 54, that is, the area of the processing chamber 42 in the horizontal direction. Therefore, when a conventional plasma processing apparatus is installed, an extra horizontal space for storing the tapered portion 54a projected from the peripheral edge of the reactor 41 must be secured.
[0010]
By the way, as the diameter of the sample W increases, a plasma processing apparatus is required that has a larger area in the horizontal direction of the processing chamber 42, that is, a larger dimension in the horizontal direction of the reactor 41. At this time, it is also required that the installation location of the apparatus does not need to be dealt with, that is, it can be installed in a narrow space. However, in the conventional apparatus, since the dimension of the tapered portion 54a is determined according to the horizontal dimension of the processing chamber 42, the dimension of the tapered portion 54a becomes longer as the processing chamber 42 becomes larger. Therefore, it is impossible to satisfy both of the two requirements of installing a plasma processing apparatus having a larger reactor 41 in a narrow space.
[0011]
On the other hand, the density distribution of the plasma generated in the reactor 41 varies depending on the composition of the reaction gas introduced into the reactor 41 and the structure of the dielectric line 54, etc., but is uniform regardless of the composition of the reaction gas. It is also required to generate plasma having an appropriate density distribution. However, in order to meet the demand with the conventional plasma processing apparatus, it is necessary to replace the dielectric line with a structure corresponding to the composition of the reaction gas to be used. Therefore, the apparatus cost is high, and much labor is required for the replacement. There was a problem.
[0012]
The present invention has been made in view of such circumstances, and an object of the present invention is to radiate microwaves into a container from a plurality of slits provided in an annular, C-shaped or spiral waveguide antenna. In addition, by adopting a configuration in which the opening area of the plurality of slits is changed by the changing member, the size of the entire plasma processing apparatus, particularly the horizontal size can be reduced even in a processing chamber having a large horizontal area. Another object of the present invention is to provide a plasma processing apparatus capable of generating a plasma having a uniform density distribution regardless of the reaction gas composition.
[0013]
[Means for Solving the Problems]
Book In the plasma processing apparatus according to the invention, an annular waveguide antenna is provided on the surface of the sealing member that seals the opening of the container, and a portion of the waveguide antenna that faces the sealing member is provided. A plurality of slits are opened, microwaves are incident on a waveguide antenna, microwaves are emitted from the slits into the container to generate plasma in the container, and the object to be processed is generated by the generated plasma. An apparatus for processing, comprising a changing member for changing the opening area of the slit In accordance with each slit, a plurality of change members are slidably provided in a plane substantially parallel to the sealing member, and a plurality of support members that respectively support the change members and corresponding change members A guide part that guides each support member to change the opening area of the slit, and a fixing part that fixes the support member at an arbitrary position of the guide part It is characterized by that.
[0014]
Book In the plasma processing apparatus according to the invention, a C-shaped or spiral waveguide antenna is provided on the surface of a sealing member for sealing the opening of the container, and the sealing member of the waveguide antenna is provided. A plurality of slits are opened in a portion facing the substrate, microwaves are incident on the waveguide antenna, microwaves are radiated from the slits into the container, and plasma is generated in the container. An apparatus for processing an object to be processed, comprising a changing member for changing an opening area of the slit In accordance with each slit, a plurality of change members are slidably provided in a plane substantially parallel to the sealing member, and a plurality of support members that respectively support the change members and corresponding change members A guide part that guides each support member to change the opening area of the slit, and a fixing part that fixes the support member at an arbitrary position of the guide part It is characterized by that.
[0015]
Microwaves are incident on an annular, C-shaped or spiral waveguide antenna disposed opposite to a sealing member that seals the opening of the container (reactor), and the microwave is incident on the sealing member of the waveguide antenna. Microwaves are radiated into the container from a plurality of slits opened in the facing portions. This microwave passes through the sealing member and is introduced into the container, and plasma is generated in the container. As described above, since the microwave can be directly incident on the waveguide type antenna without providing the protrusion as described above, the horizontal dimension of the plasma processing apparatus can be made as small as possible. Can do. On the other hand, since the microwave is guided from the waveguide antenna to almost the entire region of the container, the microwave can be uniformly introduced into the container.
[0016]
The electric field strength of the microwave radiated from the slit of the waveguide antenna described above depends on the opening area of the slit, and the smaller the opening area of the slit, the stronger the electric field strength. The density of the plasma generated in the region where the electric field strength is high is higher than the density of the plasma generated in the region where the electric field strength is relatively weak. That is, the density of plasma generated in the container can be adjusted by changing the opening area of the slit.
[0017]
Book In the invention, the opening area of the plurality of slits provided in the waveguide antenna can be changed by the changing member. Therefore, depending on the composition of the reaction gas introduced into the container, By appropriately changing the opening area, the density of the plasma generated in the reactor can be optimized.
[0019]
A plurality of change members provided in accordance with each slit are supported by a support member, and each support member is changed by a guide portion such as a groove or a rail so that the change member supported by the change member changes the opening area of the slit. Guided. The supporting member is moved along the guide portion, the changing member is slid so that each slit has an appropriate opening area, and each supporting member is fixed by the fixing portion. Thereby, the electric field intensity of the microwave radiated from the slit can be adjusted for each of the plurality of slits, and the density of the plasma generated according to each slit can be controlled separately. Therefore, irrespective of the composition of the reaction gas, the density of the plasma generated in the container can be made substantially uniform in a plane parallel to the object to be processed disposed in the container.
[0020]
Book The plasma processing apparatus according to the invention is ,in front A C-shaped first gear provided with the guide portion, a second gear meshing with the first gear, and a second gear rotating around the waveguide antenna. And a rotational drive device for driving.
[0022]
Book The plasma processing method according to the invention includes: Above The plasma processing apparatus is used to generate plasma in a container and to process an object to be processed with the generated plasma, so that a plurality of change members have a relatively narrow opening area of a corresponding slit. The generation of plasma is started after sliding, and then each change member is slid so that the opening area of the corresponding slit becomes relatively large.
[0023]
Book In the invention, the C-shaped first gear provided with the guide portion is rotated in the forward direction by rotating the second gear meshed with the first gear with the rotation driving device, or the opening of each slit. A plurality of change members that change the respective areas are advanced by a plurality of drive devices provided in accordance with each change member, so that a plurality of support members and change members attached to the guide section are linked to each drive device. The changing member is slid so that the opening area of the corresponding slit becomes relatively narrow. And the production | generation of a plasma is started by making a microwave radiate | emit into a container from each slit. In this way, by radiating microwaves from a slit having a small opening area, microwaves with strong electric field strength are radiated, so that plasma can be reliably generated within a short time, and so-called ignitability is improved. .
[0024]
On the other hand, the amount of microwave radiant energy increases as the opening area of the slit increases, and the generated plasma stabilizes as the amount of radiant energy increases. Therefore, after starting the generation of plasma, each change member is slid to make the opening of each slit relatively wide. Thereby, high-density and stable plasma can be generated.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
FIG. 1 is a side sectional view showing a structure of a plasma processing apparatus according to the present invention, and FIG. 2 is a schematic plan view of the plasma processing apparatus shown in FIG. FIG. 3 is a partially enlarged view of the plasma processing apparatus shown in FIG. The bottomed cylindrical reactor 1 is entirely made of aluminum. The upper opening of the reactor 1 is sealed with a sealing plate 4 in an airtight state. The sealing plate 4 is made of a dielectric material such as quartz glass or alumina that has heat resistance and microwave transparency and has a small dielectric loss.
[0027]
A cover member 10 formed by forming a conductive metal into a circular lid shape is fitted on the sealing plate 4 described above, and the cover member 10 is fixed on the reactor 1. An annular waveguide antenna 11 for introducing a microwave into the reactor 1 is provided on the cover member 10. The annular waveguide antenna 11 includes a bent portion 11a formed by annularly forming a U-shaped member in cross-sectional view, and a plurality of slits are formed in a portion facing the bent portion 11a of the cover member 10. 15, 15, ... are established.
[0028]
The bent portion 11a is provided slightly inward from the inner peripheral surface of the reactor 1 and concentrically with the central axis of the reactor 1, and the bent portion 11a is micro-circulated around the opening provided on the outer peripheral surface. An introduction portion 11b for introducing a wave is connected so as to be in the diameter direction of the bending portion 11a. A dielectric 14 such as a fluororesin such as Teflon (registered trademark), a polyethylene resin, or a polystyrene resin (preferably Teflon) is fitted in the introduction portion 11b and the bent portion 11a.
[0029]
A waveguide 29 extending from the microwave oscillator 30 is connected to the introduction portion 11b, and the microwave oscillated by the microwave oscillator 30 passes through the waveguide 29 and is introduced to the introduction portion of the annular waveguide antenna 11. It is incident on 11b. This incident wave is introduced from the introduction part 11b to the bending part 11a. The microwaves introduced into the bent portion 11a propagate in the dielectric 14 in the bent portion 11a as traveling waves that travel in opposite directions to each other in the bent portion 11a. A standing wave is generated by colliding at a position facing the opening of 11a. By this standing wave, a current having a maximum value flows at a predetermined interval through the inner surface of the bent portion 11a.
[0030]
At this time, in order to set the microwave mode propagating in the bent portion 11a to the rectangular TE10 which is the basic propagation mode, the size of the bent portion 11a is set to 27 mm in height according to the microwave frequency 2.45 GHz. The width is 66.2 mm. The microwave in this mode propagates through the dielectric 14 in the bent portion 11a with almost no energy loss.
[0031]
Further, when the sealing plate 4 having a diameter of 380 mm is used and Teflon (registered trademark) having a dielectric constant εr of 2.1 is fitted into the bent portion 11a, the width of the bent portion 11a from the center of the bent portion 11a. The dimension to the center of the direction is 141 mm. In this case, the circumferential length (approximately 886 mm) of the circle connecting the center of the bent portion 11a in the width direction is substantially an integral multiple of the wavelength of the microwave (approximately 110 mm) propagating in the bent portion 11a. . Therefore, the microwave resonates in the bent portion 11a, and the standing wave described above becomes high voltage / low current at the antinode position and low voltage / high current at the node position, improving the antenna Q value. To do.
[0032]
By the way, the dielectric portion 14 may not be inserted into the bent portion 11a but may be hollow. However, when the dielectric 14 is inserted into the bent portion 11a, the wavelength of the microwave incident on the bent portion 11a is shortened by 1 / √ (εr) times by the dielectric 14. Therefore, when the bent portion 11a having the same diameter is used, the current flowing through the wall surface of the bent portion 11a is greater when the dielectric 14 is loaded than when the dielectric 14 is not loaded. There are many positions where the maximum value is reached, and accordingly, a large number of slits 15, 15,. Therefore, the microwave can be introduced into the processing chamber 2 more uniformly.
[0033]
FIG. 4 is an explanatory diagram for explaining the slits 15, 15,... Shown in FIGS. As shown in FIG. 4, the slits 15, 15,... Are formed on the portion of the cover member 10 (see FIG. 2) facing the bent portion 11 a so that the diameter direction of the bent portion 11 a is the longitudinal direction. That is, it is formed in a strip shape so that the traveling direction of the microwave propagating in the bent portion 11a is perpendicular to the longitudinal direction. When the bent portion 11a has the dimensions described above, the length of each slit 15, 15,... Is 50 mm, and the width is 20 mm.
[0034]
Each of the slits 15, 15,... Is an intersection P that is a side away from the introduction portion 13 of the two points where the extension line L extending the center line of the introduction portion 11b and the circle C described above intersect. ₁ And to both of them along the circle C at positions separated from each other by (2n-1) · λg / 4 (n is an integer, λg is the wavelength of the microwave propagating in the bent portion), 15 is opened, and a plurality of other slits 15, 15,... Are opened from both slits 15, 15 to both following the circle C at intervals of m · λg / 2 (m is an integer). It is.
[0035]
As described above, the slits 15, 15,... Are provided substantially radially in the cover member 10, so that the microwave is uniformly introduced into the entire region in the reactor 1. On the other hand, as shown in FIG. 1, the annular waveguide antenna 11 is provided on the cover member 10 having the same diameter as that of the reactor 1 without protruding from the periphery of the cover member 10. Even if the diameter of the vessel 1 is large, the size of the plasma processing apparatus can be made as small as possible, and therefore can be installed in a small space.
[0036]
A through hole is formed in the peripheral wall of the processing chamber 2, and a gas introduction pipe 5 for introducing a reaction gas into the processing chamber 2 is fitted into the through hole. In addition, a mounting table 3 on which the sample W is mounted is provided in the center of the bottom wall of the processing chamber 2, and a high frequency power source 7 is connected to the mounting table 3 via a matching box 6. Further, an exhaust port 8 is formed in the bottom wall of the processing chamber 2, and the inside air of the processing chamber 2 is discharged from the exhaust port 8.
[0037]
In a predetermined area including the slits 15, 15,... Inside the cover member 10, rectangular cavities 16, 16,. Are slidably loaded with shutters 18, 18,... Made of aluminum plates having an area larger than the opening area of the slits 15, 15,. Around the bent portion 11a of the cover member 10, a first gear 21 having a C shape in plan view and having a plurality of teeth on the outer peripheral surface is arranged concentrically with the central axis of the bent portion 11a. The first gear 21 can be rotated around the central axis of the bent portion 11a by a guide member (not shown).
[0038]
A cylindrical second gear 22 is engaged with the first gear 21, and the rotation shaft of the second gear 22 is connected to the output shaft of the stepping motor 27. The rotational drive of the stepping motor 27 is controlled by a drive control device 28. The drive control device 28 performs positive and negative pulses for rotating the stepping motor 27 forward and backward according to a command given to the drive control device 28. Is supplied to the stepping motor 27 the number of times specified by the command.
[0039]
The first gear 21 is provided with a guide groove 23 having an inverted T-shape in cross section on the center line of the first gear 21, and the shutters 18, 18,. The ceramic support pieces 31, 31,... Are arranged corresponding to the slits 15, 15,. .. Are formed on the central axis of each support piece 31, 31,..., And fixing screws 32, 32,. 31, ... It is screwed from top to bottom. The lower ends of the fixing screws 32, 32, ... are projected from the lower ends of the support pieces 31, 31, ..., and stopper washers 33, 33, ... are fixed to the lower ends of the fixing screws 32, 32, .... In such a fixture 34, 34,..., The fixing screws 32, 32,... Are rotated in the forward direction so that the stopper washers 33, 33,. The pieces 31, 31,... Are fixed, and the fixing screws 32, 32,.
[0040]
Between the first gear 21 of the cover member 10 and the bent portion 11a, there is provided an arcuate opening 17 that communicates with the hollow portions 16, 16,... Described above, and the support pieces 31, 31,. The shutters 18, 18,... Are connected by crank-shaped arms 26, 26,.
[0041]
In order to perform the etching process on the surface of the sample W using such a plasma processing apparatus, the fixing screws 32, 32,... Are rotated in the reverse direction to release the fixing, and the gas introduction pipe 5 enters the processing chamber 2. Depending on the composition of the reaction gas to be introduced and the positions of the slits 15, 15,..., The width of the slits 15, 15, that is, the opening area of the slits 15, 15,. .. Are adjusted along the direction 23, the fixing screws 32, 32,... Are rotated in the forward direction to fix the support pieces 31, 31,. Start.
[0042]
When starting the generation of plasma, the drive control device 28 rotates the stepping motor 27 forward by a predetermined number of steps to engage the second gear 22, the first gear 21 meshed with the second gear 22, and the first gear 21. , And the shutters 18, 18,... Are narrowed to reduce the opening area of the slits 15, 15,... A command for increasing the opening area of the slits 15, 15,.
[0043]
For example, when the width of each slit 15, 15,... Is 20 mm, the shutter 18, 18,... Narrows the opening width of each slit 15, 15,. The shutters 18, 18, ... are moved out of the openings of the slits 15, 15, ..., and the opening width of each slit 15, 15, ... is increased to 20mm.
[0044]
By radiating microwaves from the slits 15, 15,... With a small opening area, microwaves with strong electric field strength are radiated, so that plasma can be generated reliably within a short time and so-called ignitability is improved. To do. On the other hand, the amount of microwave radiation energy increases as the opening area of the slits 15, 15,... Increases, and the generated energy stabilizes as the amount of radiation energy increases. Therefore, as described above, high-density plasma can be stably generated by widening the openings of the slits 15, 15,.
[0045]
The drive controller 28 rotates the stepping motor 27 by a predetermined number of steps to reduce the opening area of the slits 15, 15,..., And then exhausts from the exhaust port 8 to reduce the inside of the processing chamber 2 to a desired pressure. Then, the reaction gas is supplied from the gas introduction pipe 5 into the processing chamber 2. Next, a microwave of 2.45 GHz is oscillated from the microwave oscillator 30 and introduced into the annular waveguide antenna 11 through the waveguide 29 to form a standing wave there. This standing wave causes an electric field to be radiated from the slits 15, 15,... Of the annular waveguide antenna 11 into the processing chamber 2, thereby causing the slits near the sealing plate 4 in the processing chamber 2. Plasma generation is started in each region corresponding to 15, 15,.
[0046]
When a predetermined time has elapsed since the start of plasma generation, the drive control device 28 reversely rotates the stepping motor 27 by a predetermined number of steps to widen the opening area of the slits 15, 15,. As a result, high-density plasma is stably generated. The plasma propagates to the mounting table 3 while diffusing, and the surface of the sample W on the mounting table 3 is etched by the substantially uniform plasma.
[0047]
(Embodiment 2)
FIG. 5 is a schematic partial plan view showing the second embodiment, in which a waveguide antenna 12 having a terminal end is provided. FIG. 6 is an explanatory diagram for explaining the waveguide antenna 12 shown in FIG. In both figures, parts corresponding to those shown in FIG. 1 and FIG. One end of the waveguide antenna 12 is connected to a waveguide connected to the microwave oscillator, and the other end of the waveguide antenna 12 is closed. One end side of the waveguide antenna 12 is linear, and the other end side is formed into an appropriate curvature such as a C shape (arc shape) or a spiral shape (C shape in FIG. 6). It is made up of the bent part 12a.
[0048]
A plurality of strip-shaped slits 15, 15,... In the portion of the cover member 10 facing the bent portion 12 a are center axes that are parallel to the longitudinal direction of the slits 15, 15,. The slits 15, 15,... Are opened at a position m · λg / 2 from the closed end of the waveguide antenna 12. That is, each slit 15, 15,... Is opened at a position showing the maximum value of the current flowing through the bottom surface in the waveguide antenna 12, and each slit 15, 15,. An electric field is radiated from the slits 15, 15,..., And the electric field passes through the sealing plate and is introduced into the reactor.
[0049]
A plurality of racks 35, 35,... Having a plurality of teeth provided on the side surfaces thereof are slidably disposed along the openings 17 at portions corresponding to the shutters 18, 18,. The racks 35, 35,... Are connected to the shutters 18, 18,. Each of the racks 35, 35,... Is meshed with a pinion 36, 36,..., And each of the pinions 36, 36, ... has a plurality of stepping motors (not shown) arranged in accordance with each pinion 36, 36,. ) And forward and reverse rotation.
[0050]
By driving each stepping motor and rotating the pinions 36, 36,... Separately, the shutters 18, 18,... Can be arranged at different positions in the slits 15, 15,. 15, ... can be adjusted to the required opening area. Therefore, it is easy to adjust the opening area of the slits 15, 15,. Further, by rotating all the pinions 36, 36,... By the same number of steps in the same rotation direction, the opening areas of all the slits 15, 15,.
[0051]
In order to etch a sample using such a plasma processing apparatus, the pinions 36, 36,... Are rotated separately to adjust the slits 15, 15,. ,... Are rotated in the positive rotation direction by the same number of steps, thereby reducing the opening area of the slits 15, 15,. When a predetermined time has elapsed since the start of plasma generation, all the pinions 36, 36,... Are rotated in the reverse direction by the same number of steps, thereby widening the opening area of the slits 15, 15,. The surface of the sample is etched with a stable plasma.
[0052]
(Embodiment 3)
FIG. 7 is a schematic partial plan view showing the third embodiment. In the present embodiment, the annular waveguide antenna 11 shown in FIG. 2 is provided, and a rack having a plurality of teeth on the upper surface as a support member for supporting the shutters 18, 18,. Except that 37, 37,... Are slidably disposed on the cover member 10, the configuration is substantially the same as the plasma processing apparatus shown in the second embodiment.
[0053]
In order to etch a sample using such a plasma processing apparatus, the corresponding pinions 38, 38,... Are rotated by appropriate stepping motors 27, 27,. The opening area of the slits 15, 15,... Is reduced by adjusting the opening area and rotating the pinions 38, 38,. The generation of plasma is started. When a predetermined time has elapsed since the start of plasma generation, the stepping motors 27, 27,... Rotate the pinions 38, 38,. The surface of the sample is etched with a high density and stable plasma with a wide opening area.
[0054]
【The invention's effect】
As detailed above, Book In the invention, the horizontal dimension of the plasma processing apparatus can be reduced. Further, since the microwave is guided from the waveguide antenna to almost the entire region of the container, the microwave can be uniformly introduced into the container. Furthermore, since the opening area of the plurality of slits provided in the waveguide antenna can be changed by the changing member, the opening area of each slit is appropriately set according to the composition of the reaction gas introduced into the container. By changing to, the density of the plasma generated in the reactor can be optimized.
[0055]
Book In the invention, the density of the plasma generated according to each slit can be individually controlled by adjusting the electric field intensity of the microwave emitted from the slit for each of the plurality of slits. Regardless of the composition, the density of the plasma generated in the container can be made substantially uniform in a plane parallel to the workpiece disposed in the container.
[0056]
Book In the invention, a plurality of changing members are slid so that the opening area of the corresponding slit becomes relatively narrow, and generation of plasma is started, thereby radiating microwaves with strong electric field strength and shortening. Plasma can be reliably generated within the time, and so-called ignitability is improved. In addition, after starting the generation of plasma, each change member is slid to make the opening of each slit relatively wide, so that high-density and stable plasma can be generated.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing the structure of a plasma processing apparatus according to the present invention.
FIG. 2 is a schematic plan view of the plasma processing apparatus shown in FIG.
3 is a partially enlarged view of the plasma processing apparatus shown in FIG.
FIG. 4 is an explanatory diagram for explaining a slit shown in FIGS. 1 and 2;
FIG. 5 is a schematic partial plan view showing a second embodiment.
6 is an explanatory diagram for explaining the waveguide type antenna shown in FIG. 5;
7 is a schematic partial plan view showing Embodiment 3. FIG.
FIG. 8 is a side sectional view showing a microwave plasma processing apparatus of the same type as the apparatus disclosed in Japanese Patent Application Laid-Open No. 62-5600.
9 is a plan view of the microwave plasma processing apparatus shown in FIG.
[Explanation of symbols]
1 reactor
4 Sealing plate
10 Cover member
11 Annular waveguide antenna
11a Curvature
11b Introduction
12 Waveguide antenna
15 slit
16 Cavity
18 Shutter
17 Opening
21 First gear
22 Second gear
23 guide groove
27 Stepping motor
31 Support piece
32 fixing screws
35 racks
36 pinion

Claims (4)

An annular waveguide antenna is provided on the surface of the sealing member that seals the opening of the container, and a plurality of slits are provided in a portion of the waveguide antenna that faces the sealing member. The microwave is incident on the waveguide antenna, the microwave is emitted from each slit into the container to generate plasma in the container, and the processing object is processed by the generated plasma.
A changing member for changing the opening area of the slit ,
In accordance with each slit, a plurality of change members are slidably provided in a plane substantially parallel to the sealing member, and a plurality of support members that respectively support the change members, and the corresponding change members make slits. the plasma processing apparatus according to claim Rukoto includes a guide portion for guiding each support member so as to change the opening area, and a fixing portion for fixing the support member at any position of the guide portion of the. A C-shaped or spiral waveguide antenna is provided on the surface of the sealing member that seals the opening of the container, and a plurality of slits are formed in a portion of the waveguide antenna facing the sealing member. Is a device that makes microwaves incident on a waveguide antenna, radiates microwaves from the slits into the container, generates plasma in the container, and processes the object to be processed with the generated plasma Because
A changing member for changing the opening area of the slit ,
In accordance with each slit, a plurality of change members are slidably provided in a plane substantially parallel to the sealing member, and a plurality of support members that respectively support the change members, and the corresponding change members make slits. the plasma processing apparatus according to claim Rukoto includes a guide portion for guiding each support member so as to change the opening area, and a fixing portion for fixing the support member at any position of the guide portion of the. A C-shaped first gear provided with the guide portion, a second gear meshing with the first gear, and a second gear rotating around the waveguide antenna. The plasma processing apparatus of Claim 1 or 2 provided with the rotational drive apparatus to drive. A method of generating plasma in a container using the plasma processing apparatus according to claim 3 , and processing an object to be processed with the generated plasma, wherein a plurality of changing members have relative opening areas of corresponding slits. The plasma processing method is characterized in that the generation of plasma is started after sliding so as to be narrow, and then each change member is slid so that the opening area of the corresponding slit is relatively wide. .

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