JP2015039009A - Sample table, and microwave plasma processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sample table whose contact face is kept flat and smooth by lapping and that can stably hold a semiconductor wafer by forming the contact face in a substantially concave shape, and a microwave plasma processing apparatus equipped with the sample table.SOLUTION: A sample table 2 for holding a semiconductor wafer W to be plasma-processed comprises an adsorption plate that is lapped, has a contact face with which the semiconductor wafer W comes into surface contact and adsorbs the semiconductor wafer W which is in surface contact with the contact face and a supporting base plate having a concave face to which a non-contact face of the adsorption plate is adhered. The difference in depth between the substantially central part of the concave face and a distant region away from the central part is made larger than the difference in thickness between the adsorption plate in a region in contact with the central part and the adsorption plate in a region in contact with the distant region. Further, a microwave plasma processing apparatus is fitted with the sample table 2.

Description

  The present invention includes a sample stage for holding a substrate to be processed to be subjected to substrate processing, and the sample stage, generates plasma in a processing chamber by microwaves, and performs plasma processing on the substrate to be processed using the plasma. The present invention relates to a microwave plasma processing apparatus configured as described above.

  A semiconductor manufacturing apparatus includes a sample stage that holds a substrate to be processed to be subjected to plasma processing, for example, a semiconductor wafer. The sample stage includes a ceramic suction plate for electrostatically attracting a semiconductor wafer, and an electrode for electrostatic suction, a heater for heating, and the like are embedded in the suction plate. In order to process a semiconductor wafer uniformly, it is necessary to make the temperature distribution of the semiconductor wafer uniform. For this reason, the contact surface of the suction plate that contacts the semiconductor wafer is smoothed by lapping so that the thermal resistance between the contact surface and the semiconductor wafer is uniform.

  On the other hand, Patent Document 1 discloses a sample stage configured such that a recess is formed in a substrate support surface that supports a semiconductor wafer, and a predetermined space is formed between the semiconductor wafer and the substrate support surface. ing. The temperature of the semiconductor wafer is increased by forming the sample stage so that the temperature is likely to rise at the center of the semiconductor wafer, and the depth is greatest at the center of the recess and shallower from the center toward the end. The purpose is to make the uniform.

  In Patent Document 2, a concave portion having a depth of 3 to 10 μm is formed on one main surface of the plate-like ceramic body, leaving the outer peripheral portion thereof, and the undulation on the top surface of the outer peripheral portion is set to 1 to 3 μm. There is disclosed a sample stage in which a gas groove is provided in a peripheral portion of the bottom surface of the recess, and an electrostatic adsorption electrode is disposed in a plate-like ceramic body below the bottom surface of the recess.

JP 2004-52098 A JP 2003-133401 A

FIG. 10 is an explanatory diagram showing the problems of the conventional sample stage. FIG. 10A schematically shows a conventional sample stage 102 on which a semiconductor wafer W is placed. FIG. 10B shows the measurement result of the temperature distribution in the semiconductor wafer W placed on the conventional sample stage 102 in the plasma environment. When lapping is performed to smooth the contact surface of the suction plate provided on the sample stage, the contact surface has a shape in which a substantially central portion is convexly curved as shown in FIG. For this reason, the semiconductor wafer W placed horizontally with respect to the suction plate is unstable because it is supported at one point as shown in the left diagram of FIG. 10A, and is shown in the right diagram of FIG. As shown, it easily tilts to one side, and a large gap is formed between the semiconductor wafer W and the suction plate on the other side. As a result, as shown in FIG. 10B, the thermal resistance of the portion having a large gap is locally increased, the amount of heat removal is reduced, and a local high temperature portion is generated in the semiconductor wafer W. According to an experiment, a temperature difference ΔT of about 15 ° C. was detected in the semiconductor wafer W.
In addition, the above-mentioned problem generally occurs not only when the contact surface of the suction plate is lapped, but also when the center portion is curved in a convex shape as a result of performing a predetermined surface treatment. Is.

In addition, since the sample stage described in Patent Document 1 has a configuration in which the semiconductor wafer and the sample stage are not in surface contact, it is difficult to control the temperature of the semiconductor wafer with high accuracy.
Further, Patent Document 2 does not disclose means for solving the above-described problem.

  The present invention has been made in view of such circumstances, and even when the contact surface of the suction plate is subjected to a predetermined surface treatment, for example, lapping, by making the contact surface substantially concave, A sample stage capable of stably holding a substrate to be processed and a microwave plasma processing apparatus including the sample stage are provided.

  The sample table according to the present invention is a sample table for holding a substrate to be processed, and includes a contact surface that is in surface contact with the substrate to be processed and a non-contact surface that is a surface opposite to the contact surface. A suction plate that sucks the substrate to be processed that is in surface contact with the contact surface; and a support substrate that supports the substrate to be processed via the suction plate, and a concave surface to which the non-contact surface of the suction plate is bonded. The suction plate has a non-contact surface bonded to a concave surface of the support substrate to form a concave shape.

  In the sample stage according to the present invention, the difference between the depth of the central portion of the concave surface and the depth of the tapered portion separated from the central portion is the thickness of the suction plate at a portion contacting the central portion, and the tapered portion. It is larger than the difference with the thickness of the said adsorption plate in the site | part which contacts.

  In the sample stage according to the present invention, the concave surface of the support substrate is circular in a plan view, and the thickness of the suction plate in the portion that contacts the central portion is larger than the thickness of the suction plate in the portion that contacts the tapered portion. It is characterized by being thick.

The sample stage according to the present invention is characterized in that the depth of the central portion of the concave surface is 6.66 × 10 ^{−5 to} 8.33 × 10 ⁻⁵ times the diameter of the concave surface.

  The sample stage according to the present invention is characterized in that the concave surface of the support substrate has a flat bottom surface portion.

  In the sample stage according to the present invention, the concave surface of the support substrate has a trapezoidal side cross section.

  In the sample stage according to the present invention, an adhesive is infiltrated into a gap between the concave surface of the support substrate and the suction plate, and the contact surface of the suction plate has a curved concave shape.

  In the sample stage according to the present invention, the support substrate is made of an aluminum member, and includes a cooling water channel through which cooling water for cooling the substrate to be processed flows, and the suction plate is lapped on the contact surface. The ceramic member is provided with a heater for heating the substrate to be processed and an electrode for electrostatically adsorbing the substrate to be processed.

  A microwave plasma processing apparatus according to the present invention includes the above-described sample stage, and is configured to generate plasma in a processing chamber by microwaves and perform plasma processing on a substrate to be processed using the plasma. And

  In the present invention, the suction plate is bonded to the concave surface of the support substrate. The difference between the depth of the substantially central portion of the concave surface and the depth of the separated portion separated from the central portion is the thickness of the suction plate at the portion contacting the central portion and the suction plate at the portion contacting the separated portion. Therefore, even if the contact surface of the suction plate is subjected to a predetermined surface treatment and curved in a convex shape, the contact surface of the suction plate bonded to the concave surface is concave.

  In the present invention, the substrate to be processed can be cooled by passing a cooling liquid through the cooling water flow path. Further, the substrate to be processed can be heated by energizing the heater of the suction plate. Furthermore, the substrate to be processed can be electrostatically adsorbed by applying a direct current to the electrodes of the adsorption plate.

  In the present invention, the substrate to be processed held on the sample stage can be uniformly plasma-processed.

  According to the present invention, even when a predetermined surface treatment such as lapping is performed on the contact surface of the suction plate, the substrate to be processed is stably held by making the contact surface substantially concave. And the substrate to be processed can be uniformly plasma-processed.

It is sectional drawing which shows typically an example of the microwave plasma processing apparatus which concerns on embodiment of this invention. It is a sectional side view which shows typically an example of the sample stand which concerns on this Embodiment. It is an exploded side sectional view showing typically an example of a sample stand. It is a sectional side view which shows an example of a support substrate typically. It is the sectional side view which expanded the principal part which shows an example of an adsorption | suction board typically. It is explanatory drawing for demonstrating the dimension of a support substrate. It is a graph for demonstrating the dimension shape of the concave surface formed in the support substrate. It is the graph which showed the depth of the concave surface formed in the support substrate. It is explanatory drawing for demonstrating the effect | action of the sample stand which concerns on this Embodiment. It is explanatory drawing which shows the problem which the conventional sample stand has.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is a cross-sectional view schematically showing an example of a microwave plasma processing apparatus according to an embodiment of the present invention. Hereinafter, the overall configuration of the microwave plasma processing apparatus will be described, and then the details of the sample stage 2 will be described.

  The microwave plasma processing apparatus according to the embodiment of the present invention is, for example, an RLSA (Radial Line Slot Antenna) type, and includes a substantially cylindrical processing chamber 1 that is airtight and grounded. The processing chamber 1 is made of, for example, aluminum, and has a flat plate-shaped annular bottom wall 1a in which a circular opening 10 is formed in a substantially central portion, and a side wall provided around the bottom wall 1a, and the upper portion is It is open. A cylindrical liner made of quartz may be provided on the inner periphery of the processing chamber 1.

An annular gas introducing member 15 is provided on the side wall of the processing chamber 1, and a processing gas supply system 16 is connected to the gas introducing member 15. The gas introduction member 15 is arranged in a shower shape, for example. A predetermined processing gas is introduced from the processing gas supply system 16 into the processing chamber 1 through the gas introduction member 15. As the processing gas, an appropriate gas is used according to the type of plasma processing. For example, the sample stage 2 is suitably used for polysilicon (Poly-Si) etching processing that requires precise temperature control in order to perform high-precision processing. In this case, HBr gas, O ₂ gas, or the like is used. Preferably used. In addition, Ar gas, H ₂ gas, O ₂ gas, or the like is used when performing oxidation treatment such as selective oxidation treatment of the tungsten-based gate electrode.
Also, on the side wall of the processing chamber 1, a loading / unloading port 25 for loading / unloading the semiconductor wafer W to / from a transfer chamber (not shown) adjacent to the microwave plasma processing apparatus, and opening / closing the loading / unloading port 25. And a gate valve 26 is provided.

  A bottomed cylindrical exhaust chamber 11 protruding downward is provided on the bottom wall 1 a of the processing chamber 1 so as to communicate with the opening 10. An exhaust pipe 23 is provided on the side wall of the exhaust chamber 11, and an exhaust device 24 including a high-speed vacuum pump is connected to the exhaust pipe 23. By operating the exhaust device 24, the gas in the processing chamber 1 is uniformly discharged into the space 11 a of the exhaust chamber 11 and is exhausted through the exhaust pipe 23. Therefore, the inside of the processing chamber 1 can be depressurized at a high speed to a predetermined degree of vacuum, for example, 0.133 Pa.

  A columnar member 3 made of ceramic such as AlN is projected substantially vertically at the center of the bottom of the exhaust chamber 11, and a semiconductor wafer W, which is a substrate to be processed, to be subjected to plasma processing is supported at the tip of the columnar member. A sample stage 2 is provided. The sample stage 2 has a disc shape, and a guide ring 4 for guiding the semiconductor wafer W is provided on the outer edge thereof. The sample stage 2 is connected to a heater power source 6 for heating the semiconductor wafer W and a DC power source 8 for electrostatic adsorption. The sample table 2 is provided with wafer support pins (not shown) for supporting the semiconductor wafer W and raising and lowering it so as to protrude and retract with respect to the surface of the sample table 2. The detailed configuration of the sample stage 2 will be described later. Further, a high-frequency power source (not shown) for applying a bias to the semiconductor wafer W that is the substrate to be processed may be provided on the sample stage 2.

An opening formed in the upper part of the processing chamber 1 is provided with a ring-shaped support 27 along the peripheral edge thereof. The support portion 27 is made of a dielectric material such as quartz, Al ₂ O ₃ or the like, and is provided with a disk-shaped dielectric window 28 that allows microwaves to pass therethrough through a seal member 29.

  A disk-shaped slot plate 31 is provided above the dielectric window 28 so as to face the sample table 2. The slot plate 31 is locked to the upper end of the side wall of the processing chamber 1 while being in surface contact with the dielectric window 28. The slot plate 31 is made of a conductor, for example, a copper plate or an aluminum plate whose surface is gold-plated, and has a configuration in which a plurality of microwave radiation slots 32 are formed through a predetermined pattern. That is, the slot plate 31 constitutes an RLSA antenna. The microwave radiation slots 32 have, for example, a long groove shape, and are disposed close to each other so that a pair of adjacent microwave radiation slots 32 form a substantially L shape. The plurality of microwave radiation slots 32 forming a pair are arranged concentrically. Specifically, seven pairs of microwave radiation slots 32 are formed on the inner peripheral side and 26 pairs on the outer peripheral side. The length and arrangement interval of the microwave radiation slots 32 are determined according to the wavelength of the microwave and the like.

  On the upper surface of the slot plate 31, dielectric plates 33 having a dielectric constant larger than that of vacuum are provided so as to be in surface contact with each other. The dielectric plate 33 has a flat dielectric disk portion. A hole is formed in a substantially central portion of the dielectric disk portion. A cylindrical microwave incident portion protrudes from the peripheral edge of the hole substantially perpendicular to the dielectric disk portion.

  A disc-shaped shield lid 34 is provided on the upper surface of the processing chamber 1 so as to cover the slot plate 31 and the dielectric plate 33. The shield lid 34 is made of a metal such as aluminum or stainless steel. A space between the upper surface of the processing chamber 1 and the shield lid 34 is sealed with a seal member 35.

  A lid-side cooling water channel 34a is formed inside the shield lid 34, and the slot plate 31, the dielectric window 28, and the dielectric plate 33 are made to flow through the lid-side cooling water channel 34a. The shield lid 34 is configured to be cooled. The shield lid 34 is grounded.

  An opening 36 is formed in the center of the upper wall of the shield lid 34, and a waveguide 37 is connected to the opening. The waveguide 37 has a circular cross-section coaxial waveguide 37a extending upward from the opening 36 of the shield lid 34, and a horizontal cross-section extending in the horizontal direction connected to the upper end of the coaxial waveguide 37a. The microwave generator 39 is connected to the end of the rectangular waveguide 37b via a matching circuit 38. A microwave generated by the microwave generator 39, for example, a microwave having a frequency of 2.45 GHz, is propagated to the slot plate 31 through the waveguide 37. Note that as the frequency of the microwave, 8.35 GHz, 1.98 GHz, 915 MHz, or the like can be used. A mode converter 40 is provided at the end of the rectangular waveguide 37b on the side where the coaxial waveguide 37a is connected. The coaxial waveguide 37 a has a cylindrical coaxial outer conductor 42 and a coaxial inner conductor 41 arranged along the center line of the coaxial outer conductor 42, and the lower end portion of the coaxial inner conductor 41 is a slot plate 31. Fixed in the center of the connection. The microwave incident portion of the dielectric plate 33 is fitted in the coaxial waveguide 37a.

  The microwave plasma processing apparatus includes a process controller 50 that controls each component of the microwave plasma processing apparatus. The process controller 50 includes a user interface 51 including a keyboard that allows a process manager to input commands to manage the microwave plasma processing apparatus, a display that visualizes and displays the operating status of the microwave plasma processing apparatus, and the like. Is connected. The process controller 50 also stores a control program for realizing various processes executed by the microwave plasma processing apparatus under the control of the process controller 50, a process control program in which process condition data and the like are recorded. The part 52 is connected. The process controller 50 calls and executes an arbitrary process control program according to an instruction from the user interface 51 from the storage unit 52, and performs desired processing in the microwave plasma processing apparatus under the control of the process controller 50. .

  Next, details of the sample stage 2 according to the present embodiment will be described. 2 is a side sectional view schematically showing an example of the sample stage 2 according to the present embodiment, and FIG. 3 is an exploded side sectional view schematically showing an example of the sample stage 2. As shown in FIG. The sample stage 2 includes a support substrate 21 and a suction plate 23 bonded to the support substrate 21 with an adhesive 22.

  FIG. 4 is a side sectional view schematically showing an example of the support substrate 21. The support substrate 21 is made of an aluminum member, a stainless steel member, silicon carbide containing aluminum, or the like formed in a substantially disk shape having a larger diameter than the semiconductor wafer W, and a cooling water passage 21a is formed inside. The cooling water channel 21a cools the semiconductor wafer W by allowing cooling water to flow therethrough. A concave surface 21b having a circular shape in front view is formed on one end surface side (upper surface side) of the support substrate 21, an annular groove is formed on the radially outer side of the concave surface 21b, and an annular outer peripheral portion is formed on the outer side. Is formed. On the other end surface side of the support substrate 21, the outer peripheral surface is enlarged. The concave surface 21b has a flat plate shape with a trapezoidal side cross section, and the depth of the concave surface 21b increases as the plan view formed in the substantially central portion is separated from the circular bottom surface portion 21c and radially outward from the bottom surface portion 21c. And a tapered portion 21d formed so as to be shallow. The difference between the depth of the central portion of the concave surface 21b and the depth of the tapered portion 21d spaced from the central portion is that the thickness of the suction plate 23 at the portion contacting the central portion and the tapered portion 21d are contacted as described later. It is processed so as to be larger than the difference with the thickness of the suction plate 23 at the portion to be processed. That is, the concave surface 21b has such a depth that the suction plate 23 becomes concave when the suction plate 23 is bonded to the concave surface 21b.

  FIG. 5 is an enlarged side cross-sectional view of a main part schematically showing an example of the suction plate 23. The suction plate 23 is made of a ceramic member having a disk shape that is substantially the same as or larger in diameter than the concave surface 21 b of the support substrate 21. The suction plate 23 includes a plate member 23a having a contact surface 23c that contacts and sucks the semiconductor wafer W and a non-contact surface 23b that is a surface opposite to the contact surface 23c. The contact surface 23c is embossed and the top of the embossed head is smoothed by lapping. The suction plate 23 subjected to the lapping process has a substantially central portion curved in a convex shape as compared with the outer peripheral portion. As shown in FIG. 2, the non-contact surface 23 b is bonded to the concave surface 21 b of the support substrate 21 with an adhesive 22. The concave surface 21b of the support substrate 21 has a trapezoidal cross section, but the adhesive 22 is infiltrated into the gap between the concave surface 21b and the suction plate 23, and the contact surface 23c of the suction plate 23 has a smoothly curved concave shape. It becomes a shape. The suction plate 23 is embedded with a heater 23e for superheating the semiconductor wafer W and an electrode 23d for electrostatically attracting the semiconductor wafer W. The heater 23e and the electrode 23d are each provided with a heater power source 6. And a DC power supply 8 are connected.

  The concave surface 21b and the concave shape of the suction plate 23 shown in FIGS. 2 to 5 are exaggerated, and the contact surface 23c of the suction plate 23 bonded to the support substrate 21 is infinitely flat. It is a concave shape close to.

  FIG. 6 is an explanatory diagram for explaining the dimensions of the support substrate 21. The diameter φ of the circular portion in which the concave surface 21b is formed on the one end surface side of the support substrate 21 is, for example, 300 mm, the diameter φχ of the bottom surface portion 21c of the concave surface 21b is 150 mm, and the depth D at the central portion of the concave surface 21b is about 20 to 20 mm. The angle θ formed by 25 μm, the bottom surface portion 21c, and the tapered portion 21d is 179.981 ° to 179.985 °. Note that the values of the diameters φ, φχ, the depth D, and the angle θ are merely examples, and may be set as appropriate according to the dimensions and thickness of the semiconductor wafer W and the suction plate 23. However, when cutting the concave surface 21b with φ = 300 mm and depth D = about 20-25 μm, setting the diameter φχ of the bottom surface portion 21c to 150 mm is more accurate than, for example, setting the diameter φχ to 100 mm. It has been confirmed that it can be processed.

  FIG. 7 is a graph for explaining the dimensional shape of the concave surface 21 b formed on the support substrate 21. The horizontal axis is the diameter φχ, and the vertical axis is the angle θ. The graph indicated by the thick line indicates the upper limit value of the angle θ for realizing the recess having φ of 300 mm and the depth D = about 20 to 25 μm, and the thin line indicates the lower limit value of θ. The reference value is the lower limit value of θ when φχ is 150 mm.

  FIG. 8 is a graph showing the depth of the concave surface 21 b formed on the support substrate 21. The horizontal axis indicates the radial position of the concave surface 21b, and the vertical axis indicates the depth D. The plots of the square mark and the rhombus mark indicate the depth of the concave surface 21b that was cut separately, and it was confirmed that the concave surface 21b was formed with good reproducibility.

  FIG. 9 is an explanatory diagram for explaining the operation of the sample stage 2 according to the present embodiment. FIG. 9A schematically shows the sample stage 2 on which the semiconductor wafer W is placed, similarly to FIG. FIG. 9B shows the measurement result of the temperature distribution in the semiconductor wafer W placed on the sample stage 2 in the plasma environment. In the present embodiment, even when lapping is performed to smooth the contact surface 23c of the suction plate 23, the concave surface 21b is formed on the support substrate 21, and the suction plate 23 is bonded to the concave surface 21b. Therefore, as shown in FIG. 9A, the contact surface 23c has a shape in which a substantially central portion is curved flat or concave. The concave shape shown in FIG. 9A is exaggerated and is actually a concave shape that is almost flat. As described above, the semiconductor wafer W placed horizontally with respect to the suction plate 23 is stably supported by the line, and as a result, as shown in FIG. 9B, the thermal resistance of the semiconductor wafer W becomes uniform. The temperature distribution of the semiconductor wafer W becomes uniform. When an experiment similar to that of the prior art was performed using the sample stage 2 according to the present embodiment, the local temperature difference ΔT in the semiconductor wafer W could be suppressed to about 5 ° C.

  In the microwave plasma processing apparatus and the sample stage 2 configured in this way, the semiconductor wafer W is stabilized by maintaining the smoothness of the contact surface 23c by lapping and making the contact surface 23c substantially concave. Can be retained.

  In addition, since the concave surface 21b of the support substrate 21 is formed in a trapezoidal side cross section, the suction plate 23 can be stably bonded to the support substrate 21 compared to the concave surface 21b in which the concave surface 21b is formed in a mortar shape. Can do. If the concave surface 21b is formed in a mortar shape, the central portion of the suction plate 23 may float and the suction plate 23 may be peeled off. However, when the concave surface 21b is formed in a trapezoidal side cross section, the peeling of the suction plate 23 is effectively suppressed. Can do.

  Furthermore, since the concave surface 21b of the support substrate 21 has a trapezoidal side cross-sectional shape, the depth of the concave surface 21b can be easily processed with high accuracy as compared with the case of processing into an arc shape. As a result, the concave shape of the suction plate 23 can also be formed with high accuracy.

  Furthermore, the semiconductor wafer W can be brought into surface contact with the contact surface 23 c of the suction plate 23 by passing a direct current through the electrode 23 d embedded in the suction plate 23. Then, by energizing the heater 23 e with the semiconductor wafer W uniformly in surface contact with the suction plate 23, the semiconductor wafer W is overheated, and the cooling water is passed through the cooling water passage 21 a of the support substrate 21. The semiconductor wafer W can be cooled. Therefore, the temperature of the semiconductor wafer W can be uniformly controlled, and the semiconductor wafer W can be uniformly plasma processed.

  In addition, the shape of the concave surface shown by embodiment is an example, The shape is not limited. For example, if the processing accuracy can be ensured, the concave surface may be formed in an arc shape. In addition, the concave surface may be formed in a mortar shape as long as the suction plate can be bonded to the support substrate.

  In addition, the semiconductor manufacturing apparatus to which the sample stage according to this embodiment is applied is not particularly limited, and is applicable to various processing apparatuses such as PVD, CVD, plasma CVD and other film forming processing apparatuses, and etching apparatuses. Can do.

  The embodiment disclosed this time is to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Processing chamber 2 Sample stand 6 Heater power supply 8 DC power supply 21 Support substrate 21a Cooling water flow path 21b Concave surface 21c Bottom surface part 21d Tapered part 22 Adhesive 23 Adsorption plate 23a Plate member 23b Non-contact surface 23c Contact surface 23d Electrode 23e Heater W Semiconductor wafer

Claims (9)

In a sample stage for holding a substrate to be processed to be processed,
A suction plate that has a contact surface with which the substrate to be processed is in surface contact and a non-contact surface that is a surface opposite to the contact surface;
A non-contact surface of the suction plate has a bonded concave surface, and a support substrate that supports the substrate to be processed via the suction plate,
The sample table, wherein the suction plate has a non-contact surface bonded to a concave surface of the support substrate to form a concave shape.   The difference between the depth of the central portion of the concave surface and the depth of the tapered portion spaced apart from the central portion is the thickness of the suction plate at the portion that contacts the central portion and the suction plate at the portion that contacts the tapered portion. The sample stage according to claim 1, wherein the sample stage is larger than a difference from the thickness of the sample stage.   The concave surface of the support substrate is circular in a plan view, and the thickness of the suction plate at a portion contacting the central portion is larger than the thickness of the suction plate at a portion contacting the tapered portion. 2. The sample stage according to 2. The depth of the central portion of the concave surface, the sample stage according to claim 2 or claim 3 characterized in that it is a 6.66 × 10 ^-5 ~8.33 × 10 ^-5 times the concave diameter .   The sample stage according to claim 1, wherein the concave surface of the support substrate has a flat bottom surface portion.   6. The sample stage according to claim 1, wherein the concave surface of the support substrate has a trapezoidal side cross section.   The adhesive is infiltrated into a gap between the concave surface of the support substrate and the suction plate, and the contact surface of the suction plate has a curved concave shape. The sample stage described in one. The support substrate is
It is made of an aluminum member and includes a cooling water flow path through which cooling water for cooling the substrate to be processed flows.
The suction plate is
The ceramic member is provided with a lapping process on the contact surface, and includes a heater for heating the substrate to be processed and an electrode for electrostatically adsorbing the substrate to be processed. The sample stage according to any one of claims 1 to 7. A sample stage according to any one of claims 1 to 8 is provided, wherein plasma is generated in a processing chamber by a microwave, and a plasma processing is performed on a substrate to be processed by the plasma. A microwave plasma processing apparatus.

Images