JP4076645B2 - Microwave plasma processing apparatus and processing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  In the present invention, plasma is generated in a processing container using microwaves, and etching, ashing, CVD (Chemical Vapor Deposition), or the like is performed on an object to be processed such as a semiconductor substrate or a glass substrate for a liquid crystal display by the generated plasma. The present invention relates to a microwave plasma processing apparatus and a microwave plasma processing method.
[0002]
[Prior art]
  6 is a front sectional view schematically showing a conventional microwave plasma processing apparatus, and FIG. 7 is a schematic plan view of the apparatus shown in FIG. In the figure, reference numeral 31 denotes a processing container, which is made of a metal conductor and defines a processing chamber 32. In the upper part of the processing container 31 in the vertical direction, quartz glass, alumina (Al₂O₃) Or the like and is sealed in an airtight state by a sealing plate 34 formed using a dielectric plate.
[0003]
  A cover member 40 that covers the upper portion of the processing container 31 is connected to the processing container 31. A dielectric line 41 is attached to the ceiling portion in the cover member 40, and an air gap 43 is formed between the dielectric line 41 and the sealing plate 34. The dielectric line 41 is made of a dielectric material such as Teflon (registered trademark) such as fluorine resin, polyethylene resin, polystyrene resin, or quartz, and is broadened in a tapered shape from the width of the waveguide 21 to a width that covers the processing vessel 31. It is formed in a pentagon.
[0004]
  A mounting table 33 for mounting the sample substrate W is disposed at a position facing the sealing plate 34 in the processing container 31, and an exhaust device (not shown) is provided on the bottom wall 31 B of the processing container 31. A gas supply pipe 35 for supplying a required reaction gas is connected to the side wall 31 </ b> A of the processing vessel 31.
[0005]
  When, for example, the semiconductor substrate W mounted on the mounting table 33 is subjected to, for example, etching using the microwave plasma processing apparatus configured as described above, the processing chamber 31 is exhausted by exhausting from the exhaust port 38. After setting the required degree of vacuum, the reaction gas is supplied from the gas supply pipe 35. Next, the microwave is oscillated in the microwave oscillator 20 and is introduced into the dielectric line 41 including the tapered portion 41 </ b> A in order to propagate the microwave uniformly through the waveguide 21. Then, a uniform electric field is formed below the dielectric line 41, and the formed electric field passes through the air gap 43 and the sealing plate 34 and is supplied into the processing container 31 to generate uniform plasma. A uniform process such as etching is performed on the surface of the substrate W.
[0006]
[Problems to be solved by the invention]
  In the conventional microwave plasma processing apparatus as described above, in order to spread and propagate the microwaves uniformly on the dielectric line 41, the position corresponding to the edge of the sealing plate 34 and the processing container 31 is moved in the horizontal direction. A protruding taber portion 41A is provided, and the tapered portion 41A is set to a predetermined dimension according to the area of the dielectric line 41, that is, the size of the processing container 31. Therefore, when a conventional microwave plasma processing apparatus is installed, an extra horizontal space for storing the tapered portion 41A protruding from the periphery of the processing container 31 must be secured.
[0007]
  By the way, with the increase in the diameter of the substrate W, which is a sample, a microwave plasma processing apparatus having a larger processing container 31 size is required, and at the same time, it is required to reliably perform uniform plasma processing. At this time, there is also a requirement that there is no place for the installation place of the apparatus, that is, the apparatus can be installed in a space as small as possible. However, in the conventional apparatus, since the dimension of the taper portion 41A is determined according to the size of the processing container 31, it is not possible to satisfy these requirements at the same time.
[0008]
  The present invention has been made in view of such a problem, and even if the diameter of the substrate to be processed is large, the size of the entire apparatus can be made as small as possible, can be installed in a small space, and more reliably. An object of the present invention is to provide a microwave plasma processing apparatus capable of performing uniform plasma processing.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, a microwave plasma processing apparatus according to a first aspect of the present invention includes a mounting table having a mounting surface 3A on which a sample W to be processed using plasma is mounted as shown in FIG. 3; a cylindrical processing container 1 with a bottom that accommodates the mounting table 3; and disposed opposite to the mounting surface 3A to seal the processing container 1 and transmit microwaves that generate the plasma. A sealing member 4 to be introduced into the processing container 1; and a cover member having the same diameter as the processing container 1, which is formed in a circular lid shape of a conductive metal that covers a part of the upper surface and the outer peripheral side surface of the sealing member 4. 10 and; a microwave introduction port 13A for introducing the microwave is an annular channel-shaped member 12 opened on a peripheral side surface,SaidIntroduced microwaveIn rectangular TE10 modeAn annular channel member 12 that propagates and collides with a position opposite to the microwave inlet 13A to generate a standing wave; and is connected to the channel member 12 at the microwave inlet 13A, and the incident microwave is channeled The cover member 10 closes the opened portion of the channel-shaped member 12, and further, between the channel-shaped member 12 and the sealing member 4, the sealing member 4 and Disposed opposite the channel-shaped member 12;The rectangular TE10 modeThe slits 15 through which the microwave passes propagates through the channel-shaped member 12.Rectangular TE10 modeIt was opened radially so as to be orthogonal to the traveling direction of the microwave; the area surrounded by the center line of the channel-shaped member 12 was configured to be larger than the placement area on which the sample W on the placement surface 3A was placed. It is characterized by.
[0010]
  AnnularChannel memberIs typicallyChannelPart of the longitudinal section of the member formed in the shape was openedChannel memberIs formed in an annular shape and its open part isCover memberIs configured to close.Cover memberIs an annularChannel memberMay be formed integrally with each other, or may be formed as a separate member. When formed integrally, a part of the longitudinal section is openedChannel memberWhenCover memberAnd the closed cross sectionChannel memberWill be configured. AnnularChannel memberWhenCover memberAnd an antenna is configured. Further, the term “annular” is a concept including a C-shape that is a shape in which a part of the ring is missing. Because part of the ring is missingChannel memberIf a part of the center line is missing, an area is obtained on the assumption that a ring exists in the missing part and a center line also exists.
[0011]
  Annular from the microwave inletChannel memberThe microwave incident insideChannel memberTraveling waves traveling in opposite directionsChannel memberPropagating inside, both traveling wavesChannel memberStanding waves are formed by colliding with each other at a position facing the inlet.
[0012]
  By this standing wave, a current that becomes maximum at a predetermined interval flows through the wall surface of the channel-shaped member. A slit is formed in the cover member disposed opposite to the sealing member and the channel-like member under the channel-like member, and a potential difference is generated inside and outside the channel-like member across the slit by the above-described current. By this potential difference, an electric field is evenly radiated from the slit to the sealing member. That is, from the channel-shaped member to the sealing memberRectangular TE10 modeMicrowaves propagate,Rectangular TE10 modeThe microwave propagates in the sealing member from its peripheral part to the central part. thisRectangular TE10 modeThe microwave is introduced into the processing chamber through the sealing member, andRectangular TE10 modePlasma is generated by the microwave. The plasma spreads from the peripheral portion to the central portion of the processing chamber while maintaining the plasma at a high density and uniformity in the region corresponding to the region directly below the channel-shaped member.
[0013]
  Since the microwave can be directly incident on the channel-shaped member in this way, the channel-shaped member does not protrude from the processing container that defines the processing chamber, and therefore the horizontal dimension of the plasma processing apparatus can be increased. It can be made as small as possible. on the other hand,Rectangular TE10 modeMicrowaves are guided from the channel-shaped member to almost the entire processing chamber and radiated from the slit, so that the microwaves enter the processing chamber.Rectangular TE10 modeMicrowaves can be introduced uniformly. Furthermore, by setting the inner diameter of the channel-shaped member to a required size, a standing wave of a single mode (fundamental mode) can be formed in the channel-shaped member, thereby reducing energy loss as much as possible. can do.
[0014]
  AnnularChannel memberSince the area surrounded by the center line is larger than the placement area on which the sample is placed on the placement table, only the uniform region at the center of the plasma is processed. It can be made to oppose a surface, and the uniformity of a plasma processing can be improved easily.
[0015]
  Circular hereChannel memberThe center line is a curve between the inner circumference curve and the outer circumference curve of the ring, and in the case of an annular shape, it means a circular center line between the outer circumference circle and the inner circumference circle. When the sample is a circular substrate, the mounting area on which the sample is mounted refers to an area surrounded by the outer circumference of the substrate.The annular channel member may be a member in which a dielectric material for propagating microwaves is fitted.
[0016]
  Note that the sample mounting area is annular.Channel memberIt is desirable to make it smaller than the area surrounded by the inner circumference. This is because the sample can be plasma-treated with a more uniform plasma.
[0017]
  In order to achieve the above object, a microwave plasma processing apparatus according to a second aspect of the present invention is a mounting table having a mounting surface 3A on which a sample W to be processed using plasma is mounted as shown in FIG. 3; a cylindrical processing container 1 with a bottom that accommodates the mounting table 3; and disposed opposite to the mounting surface 3A to seal the processing container 1 and transmit microwaves that generate the plasma. A sealing member 4 to be introduced into the processing container 1; and a cover member having the same diameter as the processing container 1, which is formed in a circular lid shape of a conductive metal that covers a part of the upper surface and the outer peripheral side surface of the sealing member 4. 10 and; a microwave introduction port 13A for introducing the microwave is an annular channel-shaped member 12 opened on a peripheral side surface,SaidIntroduced microwaveIn rectangular TE10 modeAn annular channel-shaped member 12 that propagates and collides at a position facing the microwave inlet 13A to generate a standing wave; and is connected to the channel-shaped member 12 at the microwave inlet 13A, and the incident microwave is channeled The cover member 10 closes the opened portion of the channel-shaped member 12, and further, between the channel-shaped member 12 and the sealing member 4, the sealing member 4 and Disposed opposite the channel-shaped member 12;The rectangular TE10 modeThe slits 15 through which the microwave passes propagates through the channel-shaped member 12.Rectangular TE10 modeIt is opened radially so as to be orthogonal to the traveling direction of the microwave; the area surrounded by the inner circumference of the channel-like member 12 is configured to be larger than the placement area on which the sample W of the placement surface 3A is placed; A uniform region in the center of the plasma is configured to face the surface of the sample W to be processed.
[0018]
  In order to achieve the above object, a microwave plasma processing method according to a third aspect of the present invention is a bottomed cylindrical processing vessel sealed with a sealing member 4 that transmits microwaves as shown in FIG. The pressure in 1 is kept in vacuum; the microwave that generates plasma in the processing container 1 is introduced into the annular channel member 12 from the microwave inlet 13A provided on the peripheral side surface,The introduced microwave in rectangular TE10 modePropagate;The propagated rectangular TE10 modeThe microwave is formed from the channel-shaped member 12 into a circular lid shape of a conductive metal that closes the opened portion of the channel-shaped member 12 and covers a part of the upper surface and the outer peripheral side surface of the sealing member 4. Cover member 10 having the same diameter as container 1, formed on cover member 10 disposed between channel-shaped member 12 and sealing member 4 so as to face sealing member 4 and channel-shaped member 12. Are passed through the slits 15, 15,..., And are transmitted through the sealing member 4 and introduced into the processing container 1; slits 15, 15,... Of the mounting table 3 disposed in the processing container 1. The sample W disposed on the mounting surface 3A facing the surface is introduced into the processing container 1Rectangular TE10 modeIn the microwave plasma processing method, wherein the plasma propagates in the channel-shaped member 12, wherein the plasma propagates in the channel-shaped member 12.Rectangular TE10 modeThat have passed through the slits 15, 15,... Arranged radially so as to be orthogonal to the traveling direction of the microwaveRectangular TE10 modeOf the channel-shaped member 12Center lineThe area surrounded by is configured to be larger than the area of the sample W.
[0019]
  In order to achieve the above object, a microwave plasma processing method according to a fourth aspect of the present invention provides a sample W disposed on a mounting table 3 disposed in a processing container 1 as shown in FIG. In a microwave plasma processing method, characterized in that processing is performed using plasma generated by microwaves; pressure in a bottomed cylindrical processing container 1 sealed with a sealing member 4 that transmits microwaves is adjusted. Hold the vacuum; the microwave that generates plasma in the processing chamber 1 has an inner circle from the microwave inlet 13A provided on the peripheral side surface, and the area surrounded by the inner circle is the area of the sample W Introduced into an annular channel-shaped member 12 configured to be larger,The introduced microwave propagates in the rectangular TE10 mode.SaidpropagationWasRectangular TE modeThe microwave is molded from the channel-shaped member 12 into a circular lid shape of a conductive metal that closes the opened portion of the channel-shaped member 12 and covers a part of the upper surface and the outer peripheral side surface of the sealing member 4. A cover member 10 having the same diameter as 1 is formed on the cover member 10 disposed between the channel-shaped member 12 and the sealing member 4 so as to face the sealing member 4 and the channel-shaped member 12. Are passed through the slits 15, 15, and transmitted through the sealing member 4 and introduced into the processing container 1; the plasma propagates in the channel-shaped member 12.The introduced microwave propagates in the rectangular TE10 mode... Which have passed through slits 15, 15,..., Which are radially arranged so as to be orthogonal to the traveling direction of the microwave.Rectangular TE10 modeIt is characterized by being generated by microwaves.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described below with reference to the drawings.
[0021]
  FIG. 1 is a schematic front sectional view showing a structure of a microwave plasma processing apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic plan view of the microwave plasma processing apparatus shown in FIG. The microwave plasma processing apparatus of the present embodiment includes a bottomed cylindrical processing container 1 formed entirely of aluminum. The processing container 1 defines a processing chamber 2 in which processing of the substrate W as a sample is performed. A microwave introduction window is opened at the upper part of the processing container 1, and the microwave introduction window is sealed in an airtight state by a sealing plate 4 as a sealing member. 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 low dielectric loss.
[0022]
  A part of the upper surface and the outer peripheral side surface of the sealing plate 4 described above are covered with a cover member 10 formed by forming a conductive metal into a circular lid shape, and the cover member 10 is fixed on the processing container 1. is there. An antenna 11 for introducing microwaves into the processing container 1 is provided on the upper surface of the cover member 10. The antenna 11 is fixed to the upper surface of the cover member 10 and is formed into an annular shape.Channel memberThe annular waveguide type antenna unit 12 is provided. A plurality of slits 15, 15,. The cover member 10 also serves as a slit plate.
[0023]
  The annular waveguide antenna unit 12 is provided on a slightly inner side of the inner peripheral surface of the processing container 1 and concentrically with the central axis of the processing container 1. Further, a tubular introduction portion 13 for introducing microwaves to the annular waveguide antenna portion 12 is disposed horizontally in the diameter direction of the annular waveguide antenna portion 12 at the introduction port 13A provided on the outer peripheral surface thereof. Then, it is connected to the annular waveguide antenna unit 12. The annular waveguide antenna unit 12 and the introduction unit 13 constitute the antenna 11. A dielectric 14 such as a fluororesin such as Teflon (registered trademark), a polyethylene resin, or a polystyrene resin (preferably Teflon) is inserted into the introduction portion 13 and the annular waveguide antenna portion 12 in almost the entire inner space. It is. A horizontally-arranged waveguide 21 is connected to the introduction portion 13, and a microwave oscillator 20 is connected to the waveguide 21. The outer diameter of the waveguide 21 is equal to the outer diameter of the introduction portion 13.
[0024]
  The microwave oscillated by the microwave oscillator 20 is incident on the introduction portion 13 of the antenna 11 through the waveguide 21. This incident wave is introduced from the introducing portion 13 to the annular waveguide antenna portion 12. The microwaves introduced into the annular waveguide antenna unit 12 travel in the dielectric 14 in the annular waveguide antenna unit 12 as traveling waves that travel in opposite directions to the annular waveguide antenna unit 12. Propagate. Both traveling waves collide with each other at a position facing the inlet 13A of the annular waveguide antenna section 12, and a standing wave is generated.
[0025]
  Due to this standing wave, a current having a maximum value flows through the inner surface of the annular waveguide antenna portion 12 at a predetermined interval. This electric current causes a potential difference between the inside and the outside of the annular waveguide antenna 12 with the slits 15, 15... Sandwiched therebetween, and an electric field is evenly radiated from the slits 15, 15. That is, a microwave propagates from the annular waveguide antenna portion 12 to the sealing plate 4, and the microwave propagates through the sealing plate 4 from the peripheral portion to the central portion thereof, and the annular waveguide antenna portion 12. Then, an electric field is radiated to the sealing plate 4. When the current flows through the inner surface of the annular waveguide antenna unit 12, the microwave frequency is set so that the mode of the microwave propagating in the annular waveguide antenna unit 12 is the rectangular TE1O which is the fundamental propagation mode. The dimensions of the annular waveguide antenna unit 12 are determined according to 2.45 GHz (for example, height 27 mm, width 66.2 mm). The microwave in this mode is a single fundamental mode and propagates through the dielectric 14 in the annular waveguide antenna unit 12 with almost no energy loss.
[0026]
  Further, for example, a sealing plate 4 having a diameter of 380 mm and a thickness of 20 mm is used, and a Teflon (registered quotient drift) of εr (dielectric constant of dielectric) = 2.1 is provided in the annular waveguide antenna portion 12. When inserted, the dimension from the ring center of the annular waveguide antenna unit 12 to the center in the width direction of the annular waveguide antenna unit 12 may be 141 mm. In this case, the circumferential length (for example, approximately 886 mm) of the circle C (see FIG. 4) connecting the center in the width direction of the annular waveguide antenna portion 12 propagates in the annular waveguide antenna portion 12. It is a substantially integer multiple of the microwave wavelength (approximately 110 mm). Therefore, the microwave resonates in the annular waveguide antenna unit 12, and the above-described standing wave becomes a high voltage / low current at the antinode position and a low voltage / high current at the node position, and the antenna 11 The Q value of is improved. That is, the amplitude of the standing wave formed in the antenna 11 is increased, and microwaves with high electric field strength are radiated from the slits 15, 15,.
[0027]
  3 is an explanatory diagram for explaining the slits 15, 15,... Shown in FIGS. As shown in FIG. 3, the rectangular slits 15, 15,... Extend in the diameter direction of the annular waveguide antenna unit 12, that is, in the annular waveguide antenna unit 12. It is established so as to be orthogonal to the traveling direction of the microwave propagating.
[0028]
  Each of the slits 15, 15,... Is an intersection point P that is a side separated from the introduction portion 13 of the two points where the extension line L extending the center line in the longitudinal direction of the introduction portion 13 and the circle C described above intersect.₁, Two slits 15 and 15 are opened at positions separated by λg / 4 (λg is the wavelength of the microwave propagating in the antenna) in both directions along the circle C. 15, a plurality of other slits 15, 15,... Are opened in the two directions along the circle C at intervals of λg / 2. In this way, a plurality of regions with high electric field strength are formed in the dielectric 14 so as to be symmetric with respect to the center of the ring waveguide antenna portion 12 and the longitudinal center line of the introduction portion 13 which is a rod-like body. The
[0029]
  Each of the slits 15, 15,... Described above is positioned between adjacent regions having a high electric field strength, and an electric field having a strong electric field strength leaks from each of the slits 15, 15,. And is introduced into the processing container 1. That is, a microwave that generates plasma is introduced into the processing container 1. As described above, the slits 15, 15,... Are provided substantially radially in the cover member 10, so that the microwaves are uniformly introduced into the entire region in the processing container 1.
[0030]
  On the other hand, as shown in FIG. 1, the antenna 11 is provided on the cover member 10 having the same diameter as the diameter of the processing container 1 without protruding from the peripheral edge of the cover member 10. However, the size other than the processing container 1 of the microwave plasma processing apparatus can be reduced. Therefore, the microwave plasma processing apparatus can be installed in a small space. In other words, if the antenna 11 is enlarged, a large substrate can be processed uniformly.
[0031]
  A gas nozzle 6 that extends horizontally through the side wall 1A is provided on the side wall 1A of the processing container 1, and the degree of vacuum is slightly higher than the vacuum pressure at which the processing container 1 is exhausted from the exhaust port 18 and plasma is generated in the processing container 1. The required gas is introduced into the processing chamber 2 from the gas introduction pipe 5 connected to the gas nozzle 6. In the center of the bottom wall 1B of the processing chamber 2, there is provided a mounting table 3 having a mounting surface 3A on which a substrate W as a sample is mounted on the mounting surface 3A. A high frequency power supply 7 is connected via In addition, an exhaust port 18 is formed in the bottom wall 1B of the processing container 1, and gas inside the processing chamber 2 is discharged from the exhaust port 18.
[0032]
  The mounting area (the area of the substrate W) on which the substrate W of the mounting table 3 is mounted is the area surrounded by the center line of the annular waveguide antenna unit 12, that is, the outer circumference of the annular waveguide antenna unit 12. And an area of a diameter DA2 circle passing through the middle of the inner circumference circle. For example, when the diameter DW of the substrate is 200 mm, the diameter DA2 of the circle surrounded by the center line is 282 mm, and the mounting area is smaller than the area of the inner circumference of the diameter DA1 of the annular waveguide antenna portion 12, The uniformity of plasma treatment is improved.
[0033]
  In order to perform, for example, an etching process on the surface of the substrate W as a sample using such a microwave plasma processing apparatus, the gas is introduced after exhausting from the exhaust port 18 and reducing the pressure in the processing chamber 2 to a desired new and old pressure. A reaction gas is supplied from the pipe 5 into the processing chamber 2.
[0034]
  Next, a microwave is oscillated from the microwave oscillator 20 and introduced into the antenna 11 through the waveguide 21, and a standing wave is formed in the antenna 11. By the standing wave, the electric field radiated from the slits 15, 15,... Of the antenna 11 passes through the sealing plate 4 and is introduced into the processing chamber 2, and uniform plasma is generated in the processing chamber 2. The surface of the substrate W as a sample is uniformly etched by this plasma.
[0035]
  The density of the plasma generated on the mounting table 3 on which the substrate W having the outer peripheral circle with the diameter DW is mounted is high in the central region of the substrate W and maintains a substantially constant value up to a certain distance from the center. When the distance is exceeded, the value gradually decreases (see FIG. 5). The decrease in the value is generally small until it exceeds the circle (diameter DA2) surrounded by the inner circumference circle (diameter DA1) and the center line of the outer circumference circle of the annular waveguide antenna portion 12, but If it exceeds, it will drop greatly. This decrease in plasma density causes a decrease in the uniformity of the etching rate of the substrate. The uniformity of the etching rate is an allowable value of 10% or less, but if the area of the inner circumference circle of the diameter DA1 of the annular waveguide antenna portion 12 is made larger than the area surrounded by the outer circumference circle of the substrate W. The uniformity of the etching rate can be suppressed within 4%. Here, the uniformity of the etching rate is expressed by a percentage number obtained by multiplying (maximum value−minimum value) / (maximum value + minimum value) by 100 by the etching rate.
[0036]
  Therefore, in order to perform uniform plasma processing, the area of the circle with the diameter DA2 surrounded by the center line of the inner circumference circle and the outer circumference circle of the annular waveguide antenna 12 is set to the outer circumference of the substrate W with the diameter DW. It is desirable to make it larger than an area surrounded by a circle (an area on which the substrate W of the mounting table 3 is placed). It is further desirable to make the area of the inner circumference circle of the diameter DA1 of the annular waveguide antenna portion 12 larger than the area surrounded by the outer circumference circle of the substrate W.
[0037]
  Since the high frequency power supply 7 is connected to the mounting table 3 via the matching box 16, a bias potential is generated in the substrate W mounted on the mounting table 3, and the bias potential is controlled by controlling the power of the high frequency power supply 7. By controlling the energy of ions in the plasma independently, the processability (etching shape, etc.) of the substrate W can be improved.
[0038]
  Next, a second embodiment of the present invention will be described with reference to the plan view of FIG. In the following drawings, the same or corresponding members are denoted by the same reference numerals, and redundant description is omitted.
[0039]
  As a second embodiment of the present invention,Channel memberThe waveguide type antenna portion 112 is not an annular shape,ChannelThis member has an arc shape (C shape) in which a part of the ring is missing in one plane. In this case, one end of the waveguide antenna unit 112 is connected to the introduction unit 13 and the other end is closed. Further, the center line in the longitudinal direction of the introduction part 13 is attached so as to be in contact with the center line connecting the internal centers of the waveguide antenna part 112.
[0040]
  The diameter of the center line, which is assumed on the assumption that the waveguide antenna 112 is annular, is DA2, the diameter of the outer circumference of the substrate W as a sample is DW, and DA2 is larger than DW. The area surrounded by the imaginary center line of the diameter DA2 is larger than the area of the outer circumference of the substrate W. Accordingly, uniform plasma can be opposed to the substrate W, and uniform plasma treatment can be performed.
[0041]
  Next, data obtained as a result of measuring the plasma density is shown below. The microwave plasma processing apparatus is an apparatus for a 12-inch wafer. The main dimensions are as follows.
  Diameter of the circle surrounded by the center line of the annular waveguide antenna part: 403 mm
  Ring width of the annular waveguide antenna part: 70 mm (difference between outer radius and inner radius)
  Slit shape: 20 mm (width) x 56 mm (length)
  Seal plate shape: 500 mm (diameter) x 30 mm (thickness)
  Inner diameter of processing vessel: 550mm
  Mounting table height: 80mm
[0042]
Other specifications are as follows.
  Annular waveguide antenna shape: ring
  Number of slits: 22
  Measurement position height: 25mm above wafer surface
  Measurement direction: radial direction
  Processing chamber pressure: 20 mTorr
  Gas: Argon
[0043]
  FIG. 5 shows a graph of the measurement result of the argon electron density at this time. In this graph, the vertical axis represents the electron density (m^-3) (Logarithmic scale), the horizontal axis is the distance (mm) from the wafer center of the measurement point. The decrease in electron density at this time is 3.8% in the inner circumference circle of the annular waveguide antenna portion, and 8.2% in the center line between the inner circumference circle and the outer circumference circle of the annular waveguide antenna portion. The outer circumference of the annular waveguide antenna portion is 31%. As a result, for uniform plasma processing, the area surrounded by the center line of the inner circumference circle and the outer circumference circle of the annular waveguide antenna portion is changed to the area surrounded by the outer circumference circle of the substrate W ( The area of the inner circumference of the annular waveguide antenna unit is preferably larger than the area surrounded by the outer circumference of the substrate W. Indicates that it is more desirable.
[0044]
【The invention's effect】
  As described above, according to the present invention, an annular shapeChannel memberAnd an antenna having a slit plate in which a slit is formed, so that the part other than the processing container of the apparatus can be miniaturized, and the size of the entire apparatus can be made as small as possible even if the diameter of the substrate is large, Can be installed in a small space. More circularChannel memberThe area surrounded by the center line of the mounting table is configured to be larger than the mounting area on which the sample is mounted on the mounting surface of the mounting table, so that the high-density region of the plasma generated in the processing chamber faces the sample. Therefore, the uniformity of the plasma processing of the sample can be improved, and the uniform plasma processing can be surely performed.
[0045]
  As described above, according to the present invention, since the antenna having the annular channel-shaped member and the slit plate having the slits is provided, the part other than the processing container of the apparatus can be miniaturized, and the diameter of the substrate can be reduced. Even if it is large, the size of the entire apparatus can be made as small as possible, and it can be installed in a small space. Furthermore, since the area surrounded by the inner circumference of the annular channel-shaped member is configured to be larger than the mounting area for mounting the sample on the mounting surface of the mounting table, a region where the density of plasma generated in the processing chamber is high Can be made to face the sample, the uniformity of the plasma treatment of the sample can be improved, and a uniform plasma treatment can be reliably performed.
[Brief description of the drawings]
FIG. 1 is a schematic front sectional view of a microwave plasma processing apparatus according to a first embodiment of the present invention.
FIG. 2 is a schematic plan view of the microwave plasma processing apparatus shown in FIG.
3 is an explanatory view of a slit of a cover member of the microwave plasma processing apparatus shown in FIG.
FIG. 4 is a schematic plan view of a microwave plasma processing apparatus according to a second embodiment of the present invention.
FIG. 5 is a graph showing data obtained by measuring plasma electron density in the radial direction of a substrate.
FIG. 6 is a schematic front sectional view of a conventional microwave plasma processing apparatus.
FIG. 7 is a schematic plan view of a conventional microwave plasma processing apparatus.
[Explanation of symbols]
  1 Processing container
  1A side wall
  1B Bottom wall
  2 treatment room
  3 mounting table
  3A mounting surface
  4 Sealing plate
  5 Gas introduction pipe
  6 Gas nozzle
  7 High frequency power supply
10 Cover member
11 Antenna
12 Annular waveguide antenna
13 Introduction
13A inlet
14 Dielectric
15 slit
16 Matching box
18 Exhaust port
20 Microwave oscillator
21 Waveguide
112 Waveguide type antenna section
C yen
DA1 diameter
DA2 diameter
DW diameter
L extension line
P₁     Intersection
W substrate

Claims (4)

A mounting table having a mounting surface for mounting a sample to be processed using plasma;
A bottomed cylindrical processing container for accommodating the mounting table;
A sealing member that is disposed to face the placement surface, seals the processing vessel, and transmits microwaves that generate the plasma to be introduced into the processing vessel;
A cover member having the same diameter as that of the processing container, which is formed in a circular shape of a conductive metal covering a part of the upper surface and the outer peripheral side surface of the sealing member;
Wherein an annular channel-shaped member of the microwave introduction port is opened in the peripheral side surface for introducing microwaves, the introduced microwave is propagated in the rectangular TE10 mode, colliding at a position opposed to the microwave introduction port An annular channel member that generates a standing wave;
An introduction portion connected to the channel-shaped member at the microwave introduction port and introducing the incident microwave into the channel-shaped member;
The cover member closes the opened part of the channel-shaped member, and is further disposed between the channel-shaped member and the sealing member so as to face the sealing member and the channel-shaped member, The slits through which the rectangular TE10 mode microwaves pass are radially opened so as to be orthogonal to the traveling direction of the rectangular TE10 mode microwaves propagating through the channel member;
An area surrounded by a center line of the channel-shaped member is configured to be larger than a placement area for placing the sample on the placement surface;
Microwave plasma processing equipment. A mounting table having a mounting surface for mounting a sample to be processed using plasma;
A bottomed cylindrical processing container for accommodating the mounting table;
A sealing member that is disposed to face the placement surface, seals the processing vessel, and transmits microwaves that generate the plasma to be introduced into the processing vessel;
A cover member having the same diameter as that of the processing container, which is formed in a circular shape of a conductive metal covering a part of the upper surface and the outer peripheral side surface of the sealing member;
Wherein an annular channel-shaped member of the microwave introduction port is opened in the peripheral side surface for introducing microwaves, the introduced microwave is propagated in the rectangular TE10 mode, colliding at a position opposed to the microwave introduction port An annular channel member that generates a standing wave;
An introduction portion connected to the channel-shaped member at the microwave introduction port and introducing the incident microwave into the channel-shaped member;
The cover member closes the opened part of the channel-shaped member, and is further disposed between the channel-shaped member and the sealing member so as to face the sealing member and the channel-shaped member, The slits through which the rectangular TE10 mode microwaves pass are radially opened so as to be orthogonal to the traveling direction of the rectangular TE10 mode microwaves propagating through the channel member;
An area surrounded by an inner circumference of the channel-shaped member is configured to be larger than a placement area on which the sample is placed on the placement surface, and a uniform region in the central portion of the plasma is treated with the sample. Characterized in that it is configured to face the surface;
Microwave plasma processing equipment. Holding the pressure in a bottomed cylindrical processing vessel sealed with a sealing member that transmits microwaves in a vacuum;
Introducing a microwave that generates plasma in the processing vessel into an annular channel-shaped member from a microwave introduction port provided on a peripheral side surface, and propagating the introduced microwave in a rectangular TE10 mode ;
The propagated rectangular TE10 mode microwave is a conductive metal circle that closes the open part of the channel-shaped member from the channel-shaped member and covers a part of the upper surface and the outer peripheral side surface of the sealing member. A cover member that is shaped like a lid and has the same diameter as the processing container, and is disposed between the channel-shaped member and the sealing member so as to face the sealing member and the channel-shaped member. Passing through the slit formed in the cover member and allowing the sealing member to pass through, and introducing it into the processing container;
A sample disposed on a mounting surface facing the slit of the mounting table disposed in the processing container is processed using plasma generated by a rectangular TE10 mode microwave introduced into the processing container. In a microwave plasma processing method characterized by:
The plasma is generated by the rectangular TE10 mode microwaves that have passed through the slits arranged radially to be orthogonal to the traveling direction of the rectangular TE10 mode microwaves propagating in the channel member;
The area surrounded by the center line of the channel-shaped member is configured to be larger than the area of the sample;
Microwave plasma processing method. In a microwave plasma processing method, wherein a sample disposed on a mounting table disposed in a processing container is processed using plasma generated by microwaves;
Holding the pressure in the bottomed cylindrical processing vessel sealed with a sealing member that transmits the microwave in a vacuum;
The microwave that generates plasma in the processing container has an inner circle from a microwave inlet provided on a peripheral side surface, and the area surrounded by the inner circle is configured to be larger than the area of the sample. Introduced into an annular channel-shaped member and propagating the introduced microwave in a rectangular TE10 mode ;
The propagated rectangular TE10 mode microwave is a conductive metal circle that closes the open part of the channel-shaped member from the channel-shaped member and covers a part of the upper surface and the outer peripheral side surface of the sealing member. A cover member that is shaped like a lid and has the same diameter as the processing container, and is disposed between the channel-shaped member and the sealing member so as to face the sealing member and the channel-shaped member. Passing through the slit formed in the cover member and allowing the sealing member to pass through, and introducing it into the processing container;
The plasma is generated by the rectangular TE10 mode microwaves that have passed through the slits arranged radially to be orthogonal to the traveling direction of the rectangular TE10 mode microwaves propagating in the channel-shaped member. Features;
Microwave plasma processing method.

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