JP2010016176A - Test piece holder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the generation of particles or the scattering of particles and shorten an exhausting time necessary for evacuation. <P>SOLUTION: The test piece holder has a base and a projected part provided on the principal surface of the base, wherein the projected part includes a projected end face substantially parallel to the principal surface; and a side surface, continued from the projected end surface to the principal surface, includes a projected curved surface continued to the peripheral rim of the projected end face and a recessed curved surface continued from the projected curved surface to the principal surface. In this case, a distance from the parallel plane to the principal surface is made larger than a distance from the top surface to a plane parallel to the principal surface through the boundary between the projected curved surface and the recessed curved surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a polishing process, an inspection process, a transfer process and the like for each sample such as a silicon wafer and a glass substrate in each manufacturing process of a silicon wafer used for manufacturing a semiconductor integrated circuit and a glass substrate used for manufacturing a liquid crystal display device. The present invention relates to a sample holder that holds a sample when processing is performed.

  Samples of semiconductor wafers made of silicon or other materials used in the manufacture of semiconductor integrated circuits and glass substrates used in the manufacture of liquid crystal display devices are held multiple times on the sample stage of manufacturing equipment or inspection equipment during the manufacturing process. Is done. Various apparatuses and methods for holding a sample on a sample stage have been proposed depending on the type of manufacturing process.

  In recent years, demands for miniaturization and high density of semiconductor integrated circuits and shortening of manufacturing time of integrated circuits have been further increased. Accordingly, performance required for the sample holder, for example, suppression of particle generation due to frictional wear between the sample and the sample holder, suppression of scattering of particles attached to the surface of the sample holder, and, for example, vacuum There is an increasing demand for shortening the exhaust time required to adsorb the sample with sufficient strength when it is pulled.

For example, in Patent Documents 1 to 3 below, a sample is provided on a top surface of a pin by providing a plurality of pins on the main surface of the substrate and evacuating the gap between the top surface of the pins and the main surface of the substrate. A sample holder for holding each is disclosed. For example, in Patent Document 1, when the sample is detached from the sample holder using a lift pin or the like by mirror polishing the top surface and side surface of the pin of the sample holder, the top surface and side surface of the pin It has been proposed that the generation of particles can be prevented because the contact is smooth and the coefficient of friction is reduced even if the contact is made. Patent Document 2 proposes that after forming a pin having a flat top surface, the peripheral portion of the top surface of the pin is rounded and smoothly curved. In Patent Document 3, as a means for reducing the contact ratio between the sample and the pin in order to reduce the generation of particles due to the contact between the sample and the pin, the pin is truncated cone-shaped, the truncated pyramid shape, and the cylinders having different diameters are stacked. It has been proposed to use a different shape. Further, for example, in Patent Document 1, as an example of a method for manufacturing a sample holder, a protrusion having a surface substantially vertical at a position corresponding to a mask pattern by sandblasting after a mask pattern is provided on the surface of a substrate. Forming part.
JP 2003-86664 A JP-A-9-283605 Japanese Patent Laid-Open No. 10-242255

  However, in the above Patent Documents 1 to 3, the object is only to suppress particles from the sample holder, and no consideration is given to shortening the time required to adsorb the sample. Further, in Patent Document 1, the surface of the protruding portion is mirror-finished by buffing after sandblasting, but when buffing, a force is easily applied to the bonding corner between the protruding portion and the surface of the substrate. There was also a problem that the protrusion was damaged. The present invention has been made to solve this problem.

  In order to solve the above-mentioned problems, the present invention provides a sample holder having a base and a protrusion provided on one main surface of the base, the protrusion being substantially the same as the one main surface. A convex curved surface portion that has a parallel projecting end surface, and a side surface that extends from the projecting end surface to the one main surface, and a concave curved surface portion that continues from the convex curved surface portion to the one main surface; The distance from the parallel plane to the one principal surface is greater than the distance from the top surface to the plane parallel to the one principal surface through the boundary between the convex curved surface portion and the concave curved surface portion. A sample holder is provided.

  In addition, it is preferable that the cutting line by the plane perpendicular to the one main surface passing through the center line of the protruding end surface has a larger inclination as it approaches the protruding end surface from the one main surface.

  Moreover, it is preferable that the one main surface of the base body is composed of a surface of a single crystal layer.

  The single crystal layer is preferably provided on the surface of a base portion made of a silicon carbide sintered body.

  The present invention is also a sample holder for holding a sample disposed on the one main surface side by a protrusion provided on one main surface of the substrate, wherein the protrusion is the one main surface. And a plurality of step regions in which convex curved surfaces and concave curved surfaces are alternately and continuously arranged on a side surface continuous from the protruding end surface to the one main surface. A holder is also provided.

  According to the sample holder of the present invention, generation of particles from the sample holder and scattering of particles attached to the surface of the sample holder can be suppressed. Further, for example, it is possible to shorten the exhaust time required for adsorbing the sample with sufficient strength when evacuated.

  Hereinafter, the sample holder of the present invention will be described. FIG. 1 is a schematic cross-sectional view illustrating the configuration of a wafer chuck 20 that is one embodiment of a sample holder of the present invention. FIG. 1A is a plan view of the wafer chuck 20, and FIG. 1B is a sectional view taken along line XX of FIG. The wafer chuck 20 is provided with a recessed portion 12 on the main surface side of the disk-shaped substrate 3, and an annular seal wall 15 is formed on the outer periphery of the recessed portion 12. The bottom surface (main surface 3a) of the recess 12 is provided with a plurality of pins 1 that protrude from the main surface 3a. The projecting end surfaces (top surfaces 1 a) of the plurality of pins 1 are positioned substantially in the same plane as the top surface 15 a of the seal wall 15. Further, an exhaust hole 16 is formed in the inside of the base 3, and the exhaust hole 16 communicates with a suction port 16 a formed on the bottom surface (main surface 3 a) of the recess 12. The plurality of pins 1 are preferably arranged concentrically from the center of the main surface of the ceramic substrate 3.

  In the wafer chuck 20, for example, the semiconductor wafer 50 is placed so that the peripheral portion of the semiconductor wafer 50 is in contact with the top surface 15 a of the seal wall 15 and is also in contact with the top surfaces 1 a of the plurality of pins 1 at the same time. The In this state, vacuum suction is performed by a vacuum pump (not shown) connected to the exhaust hole 16 to reduce the pressure in the space surrounded by the wafer 50 and the recessed portion 12, so that the wafer 50 is placed on the top surface 1 a of the pin 1. And the top surface 15a of the sealing wall are held by suction.

  FIG. 2 is a cross-sectional view illustrating a plurality of pins 1 provided on the base 3 of the wafer chuck 20. The base 3 is made of a ceramic such as silicon carbide, for example. The pin 1 of the present embodiment includes a protruding end surface (top surface 1a) substantially parallel to one main surface 3a of the base 3 made of ceramics. FIG. 2 is a cross-sectional view taken along a plane that passes through the center of the protruding end surface (top surface 1a) of the pin 1 and is perpendicular to the one principal surface 3a. The pin 1 has a convex curved surface portion 4a continuous from the top surface 1a to the principal surface 3a of the base 3, a convex curved surface portion 4a continuous from the peripheral edge of the top surface 1a, and a concave curved surface portion 4b continuous from the convex curved surface portion 4a to the principal surface 3a. It has. In the pin 1, the concave curved surface portion 4b is larger than the convex curved surface portion 4a. That is, in the sectional view shown in FIG. 2, the height from the boundary 5 to the top surface 1a is higher than the height H1 from the main surface 3a of the base 3 to the boundary 5 between the convex curved surface portion 4a and the concave curved surface portion 4b. The length H2 is made smaller. In the present embodiment, for example, the height H1 is 20 μm to 40 μm, and the height H2 is 200 μm to 300 μm. In addition, the surface of the convex curved surface part 4a and the concave curved surface 4b may be provided with minute unevenness. For example, in the surface roughness curves of the convex curved surface portion 4a and the concave curved surface FIG. 4b, there may be minute irregularities in which the difference between the maximum height and the minimum height is about 30 μm.

  That is, in the pin 1, in the cross section shown in FIG. 2, the cross-sectional line of the concave curved surface portion 4 b corresponds to the straight line connecting the boundary 5 to the lower end of the side surface 4 (joining end with the main surface 3 a of the base 3) 7 3 is curved in a concave shape toward the side closer to the main surface 4a. That is, the wafer chuck 20 is sandwiched between a plane C passing through the boundary 5 and perpendicular to the main surface 3a of the substrate 3 and a plane passing through the lower end 7 parallel to the plane C in the sectional view shown in FIG. In this area, the area of the portion corresponding to the pin 1 is made smaller than the area of the portion corresponding to the space other than the pin 1.

  In the wafer chuck 20, for example, when the semiconductor wafer 50 is vacuum-sucked, the space portion other than the pins 1 is air that passes through the region surrounded by the wafer 50 and the recess 12 when vacuum suction is performed by a vacuum pump (not shown). It becomes a way. In the region surrounded by the wafer 50 and the recess 12, the pin 1 becomes an obstacle that hinders the air flow during vacuum suction. For this reason, when the ratio of the volume occupied by the pins 1 in the region surrounded by the wafer 50 and the recessed portion 12 is relatively large, the air resistance (exhaust conductance) during vacuum suction becomes relatively large.

  In the wafer chuck 20 of the present embodiment, the side surface 4 of the pin 1 is provided with a concave curved surface portion 4b that continues from the convex curved surface portion 4a to the one main surface 3a, and the side surface 4 is opposed to the convex curved surface portion 4a of the side surface 4. The concave curved surface portion 4b is made larger. For this reason, the ratio of the volume occupied by the pins 1 in the region surrounded by the wafer 50 and the recessed portion 12 is relatively small. Therefore, in the wafer chuck 20, the air resistance (exhaust conductance) during vacuum suction is relatively small, and the wafer 50 can be vacuum-sucked with sufficient strength in a relatively short time.

  Further, in the wafer chuck 20 of the present embodiment, the side surface 4 is provided with a convex curved surface portion 4 a continuous with the periphery of the top surface 1 a, and the wafer 50 is placed on the top surface 1 a of the pin 1. Scratches and particle generation are suppressed. 3A and 3B are examples of the cross-sectional shape of the pin of the sample holder, and show a cross-sectional shape different from that of the pin 1. FIG. 3 (a) and 3 (b), the same components as those of the pin 1 shown in FIGS. 1 and 2 are denoted by the same reference numerals. In the pin 20 shown in FIG. 3A, a corner 1 c is formed on the periphery of the top surface 1 a of the pin 1. When the corner portion 1 c as shown in FIG. 3A is formed, when the wafer 50 is placed on the top surface 1 a of the pin 1, the corner portion 1 c and the wafer 50 are in sliding contact with each other, and the wafer 50 is scratched. In some cases, scratches and particles were generated. On the other hand, in the pin 1 shown in FIG. 2, a convex curved surface portion 4 a connected to the periphery of the pin 1 is provided on the periphery of the top portion 1 a of the pin 1. For this reason, in the pin 1 shown in FIG. 2, when the wafer 50 is placed on the top surface 1a, even if the wafer 50 may come into contact with the convex curved surface portion 4a, the scratches on the wafer 50 are not generated. It is suppressed.

  In the pin 30 shown in FIG. 3B, the side surface 4 is a convex curved surface that extends from the top surface 1 a to the main surface 3 a of the base 3. In this case, the distance between the side surface 4 and the wafer 50 is relatively small, and the particles P may be sandwiched between the wafer 50 and the side surface 4. When the side surface 4 is convex, the vector component (indicated by an arrow in FIG. 3) perpendicular to the side surface 4 is inclined so as to face the wafer 50 even in a portion relatively close to the wafer 50. Yes. For this reason, the fine particles adhering to the side surface 4 are easily urged toward the wafer 50 due to the vibration of the wafer chuck 20. For this reason, there has been a problem that particles adhering to the side surface 4 are likely to adhere to the wafer 50. Further, when the side surface 4 is uniformly formed in a convex curved surface shape, the proportion of the volume occupied by the pins 1 in the region surrounded by the wafer 50 and the recessed portion 12 is relatively large. In this case, as described above, the air resistance (exhaust conductance) during vacuum suction is relatively large. That is, when the side surface 4 is uniformly convex, the time required to vacuum-suck the wafer 50 with sufficient strength is relatively long.

  On the other hand, in the pin 1 shown in FIG. 2, the side surface 4 is provided with a concave curved surface portion 4b continuous from the convex curved surface portion 4a to the one main surface 3a. For this reason, in the pin 1, in particular, the distance between the concave curved surface portion 4 b and the wafer 50 is relatively large, and the particles P are prevented from being caught in the gap between the wafer 50 and the side surface 4. Further, in the pin 1, the vector component (indicated by an arrow in FIG. 2) perpendicular to the concave curved surface portion 4 b is parallel to the main surface 3 a, particularly in the portion of the concave curved surface portion 4 b that is relatively close to the wafer 50. Tilt to face. For this reason, even when vibration occurs in the wafer chuck 20, fine particles adhering to the side surface 4 (particularly the concave curved surface portion 4 b) are not parallel to the main surface 3 a from the side surface 4, but in a direction toward the wafer 50. It is energized in the direction to go away. For this reason, the adhesion of the particles adhering to the side surface 4 (particularly the concave curved surface portion 4b) to the wafer 50 is well suppressed. Further, as described above, the air resistance (exhaust conductance) at the time of vacuum suction is relatively small in the pin 1, and the time required to vacuum-suck the wafer 50 with sufficient strength is relatively short.

  For example, the wafer chuck 20 of the present embodiment may be formed of a sintered body mainly composed of silicon carbide, alumina, silicon nitride, or the like. In particular, it is preferably made of a silicon carbide sintered body. Since the silicon carbide sintered body can have a thermal conductivity of 180 W / (m · K) or more at room temperature, it is excellent in heat dissipation even when heat is locally applied to the sample, and a sample accompanying thermal expansion. This distortion is less likely to occur, and accuracy deterioration due to heat generated during exposure in semiconductor manufacturing can be reduced. The thermal conductivity at room temperature is a value measured at a measurement temperature in the range of 22 ° C. to 24 ° C., and the thermal conductivity measured at any set temperature within this temperature range is 180 W / (m -K) Indicates that it is greater than or equal to Furthermore, even in an environment exceeding the room temperature, the thermal conductivity can be maintained at a high value, and for example, the thermal conductivity of 60 W / (m · K) or more can be maintained even in applications at 600 ° C. or higher.

  The silicon carbide sintered body preferably has an average crystal grain size in the range of 3 to 10 μm. When the average particle size is 3 μm or more, the crystal particles in the silicon carbide sintered body are relatively sufficiently filled, and the mechanical properties of the sintered body are made relatively good. In addition, by setting the crystal having an average crystal grain size of 10 μm or less, it is possible to relatively reduce the residual voids existing between the crystals, for example, to favorably suppress the residual particles to the voids. Therefore, the average crystal grain size is preferably in the range of 3 to 10 μm, and more preferably in the range of 3 to 7 μm.

The silicon carbide sintered body preferably has a density of 3.18 g / cm ³ or more, a Young's modulus of 440 GPa or more, and a specific rigidity of 135 GPa · cm ³ / g or more, and is placed on the top surface 1 a of the pin 1. It becomes possible to maintain the flatness of the obtained sample with high accuracy. Further, when the linear expansion coefficient is 2.6 × 10 ⁻⁶ / ° C. or less at room temperature, it becomes a material suitable as a member for a semiconductor manufacturing apparatus in combination with the heat dissipation described above. In addition, since the average void diameter is 1.5 μm or less and the maximum void diameter is 5 μm or less, even if the member is in direct contact with the sample, the void is small and the generation of particles generated between silicon carbide crystals is suppressed. be able to. In the wafer chuck 20 of the present embodiment, for example, a single crystal layer of silicon carbide is provided on the surface of a base substrate made of a silicon carbide sintered body.

  Next, an embodiment of a manufacturing method for obtaining the wafer chuck 20 as the sample holder will be described. FIG. 4 is a flowchart of the manufacturing method of the present embodiment, and FIG. 5 is a schematic cross-sectional view illustrating the manufacturing method of the present embodiment.

  First, the base 3 is produced (step S102). The production of the substrate 3 will be described in detail. A raw material powder obtained by adding at least a boron compound powder and a carbon compound powder as additives to silicon carbide powder as a main component of the substrate is obtained. Next, the raw material powder is molded using various molding methods to obtain a molded body, and then the primary sintering is completed at a temperature at which silicon carbide particles are suppressed from growing, and primary sintering is performed. After obtaining the body, hot isostatic pressing (HIP) processing is performed.

The description of the base 3 will be described in more detail. Silicon carbide powder as the main component, boron carbide (B ₄ C), metal boron, etc. as boron compounds that form boron components as additives, carbon compounds that form carbon components, such as carbon black, graphite, etc. A phenol resin or coal tar pitch that can generate carbon can be used. The content of these additives depends on the amount of oxygen in the raw material powder, and it is necessary that 0.15 to 3 mol of boron and 1 to 5 mol of carbon remain with respect to 1 mol of oxygen in the silicon carbide raw material. It is.

  These raw material powders are weighed at a predetermined ratio and mixed thoroughly by a mixing means such as a ball mill, and then a binder is added to the powder, and a known molding method such as press molding, extrusion molding, casting molding, cold A molded body is obtained by molding into a desired shape by isostatic pressing or the like. In addition, when phenol resin etc. are added as an additive, carbon can be produced | generated by carrying out the calcination process in 600-800 degreeC in a non-oxidizing atmosphere, and thermally decomposing.

  Next, in order to obtain high thermal conductivity, the sintered body obtained as described above is subjected to primary sintering at a relatively low temperature of 1900 to 2100 ° C. in a vacuum or in an inert atmosphere such as Ar. As a result, since the grain growth can be suppressed without increasing the activity by reducing the amount of heat at the time of primary sintering, it is possible to suppress the grain growth of the silicon carbide particles of the molded body, and the voids existing between the crystals are also small. can do. When the primary sintering temperature is lower than 1900 ° C., the crystal does not sinter, and it becomes difficult to eliminate sufficient voids no matter how much the HIP treatment is performed thereafter. On the other hand, when the temperature is higher than 2100 ° C., the crystals of the primary sintered body will be enlarged, so that when the HIP treatment is further performed, the crystals of the silicon carbide-based sintered body that can be obtained no matter how low the temperature is, Large, void disappearance becomes difficult. Furthermore, if the crystals are not sufficiently sintered, the bonding of the particles will be insufficient, and if this silicon carbide sintered body is used for a substrate holding disk, the grains will be shattered during blasting during the formation of protrusions. It is easy to cause chipping. In addition, when the crystal is enlarged, a defect portion is generated at a time when one crystal is crushed, and this case is also not preferable at the time of blasting when forming a protrusion.

  Finally, the obtained primary sintered body is subjected to HIP treatment. As a result, voids having a void diameter exceeding 5 μm can be almost eliminated while maintaining the size of the silicon carbide crystal substantially the same as the size at the end of the primary sintering. In addition, it becomes possible to control the solid solution of an additive composed of a compound of boron or carbon or a cation in the additive into silicon carbide, and the grain growth of silicon carbide particles can be effectively suppressed.

  In the firing step, primary sintering is performed in a vacuum atmosphere at a temperature of 1900 to 2100 ° C., and HIP treatment is performed in an inert gas atmosphere at a temperature of 1800 to 2000 ° C. and 180 MPa or higher to obtain a silicon carbide-based sintered material. The body can have an average void diameter of 1.5 μm or less and a maximum void diameter of 5 μm or less. When used as a substrate holding disk or a wafer chuck 200 as a member of a semiconductor or liquid crystal manufacturing apparatus, a silicon carbide crystal Generation of particles that occur in the meantime can be suppressed. When the temperature of the HIP process is lower than 1800 ° C., the densification is not promoted because the temperature is lower than the temperature at which the primary sintered body is formed. Furthermore, it is preferable to set the temperature of HIP treatment at a temperature lower than 100 ° C. below the temperature of primary sintering, and if this temperature range is reached, the pressure can be increased when the crystal is softened. Easily disappear. On the other hand, when the temperature is higher than 2000 ° C., the temperature range is higher than the temperature of primary sintering, so that crystal growth is promoted and voids are not easily lost. It tends to be low. At the same time, by setting the inert gas atmosphere to 180 MPa or more, voids existing between the silicon carbide particles are crushed, and the voids are more likely to disappear.

  More preferably, the primary sintering temperature is fired in a vacuum atmosphere of 1950 to 2050 ° C., and the HIP treatment temperature is 1850 to 1950 ° C. and an inert gas atmosphere of 190 MPa or more.

Further, as additives, TiC, TiN, a compound of titanium such as TiO ₂ 200ppm or more in terms of titanium, and is preferably added in the range 400 ppm. If it is less than 200 ppm, the thermal conductivity of the obtained sintered body is 180 W / (m · K) or higher, and the thermal conductivity at 600 to 800 ° C. cannot be 60 W / (m · K) or higher. If it exceeds 400 ppm, these metal compounds are liable to be dissolved in silicon carbide crystals, and the strength and rigidity of the silicon carbide based sintered body are deteriorated. Moreover, it becomes easy to produce | generate a boron and compound which are other sintering auxiliary agents, and sinterability will be inhibited, and influences, such as a density not going up, will come out.

  In the present embodiment, for example, a single crystal layer of silicon carbide is formed on the surface of the base substrate of the silicon carbide sintered body produced as described above, for example, by a known CVD method. The single crystal layer has a sufficiently small amount of voids and the like as compared with the sintered body, and the generation of particles due to the dropping of particles, the adhesion of particles into the voids, and the like are relatively sufficiently suppressed. Note that the single crystal layer provided on the surface of the base substrate is not limited to silicon carbide, and, for example, a sapphire single crystal may be attached. Further, an amorphous layer may be formed on the surface of the base substrate by, for example, a CVD method.

  A resist is applied to the main surface of the base 3 prepared as described above to form the first resist layer 40 (step S104). The resist coating may be performed using a known method such as a laminate method or a spin coater method. As the resist, a known photosensitive resin such as a urethane-based or silicon-based photosensitive resin may be used. The resist may be a so-called negative type, positive type, or any type of resist. Hereinafter, the case where a so-called negative resist is used will be described.

  Next, a predetermined portion of the first resist 40 is exposed and exposed (step S106). The first resist layer 40 is a negative type, and the exposed portion 51 is exposed and cured. In the present embodiment, the resist coating process in step S103 and the exposure process in step 104 are repeatedly performed. The resist coating and exposure are repeated until a desired exposure pattern is formed, that is, until the determination in step S108 is YES. In the present embodiment, as shown in FIG. 5, a multilayer (four layers) resist layer is sequentially formed from the first resist layer 40 to the fourth resist layer 46, and each layer is sequentially exposed. For the second resist layer 42 and subsequent portions, a portion corresponding to the inner region of the exposed portion of the previous layer is exposed. As a result, as shown in FIG. 5C, a layered structure of resist layers is formed having exposed portions 52 to 56 that are stacked in steps so that the cross-sectional area parallel to the substrate decreases toward the upper side. The

  Next, the layered structure of resist layers exposed in steps is developed (step S110), and as shown in FIG. 5D, the cross-sectional area parallel to the substrate is reduced toward the upper side. A resist pattern 60 laminated in steps is formed on the surface of the substrate 3.

In this state, particles are sprayed from the resist pattern 60 side, and the surface of the substrate 3 is blasted (step S112). Specifically, for example, using a known blasting apparatus, particles such as aluminum oxide and silicon carbide are ejected from a nozzle together with gas toward the surface of the substrate 3 on which the resist pattern 60 is formed. At that time, the injection flow rate may be set to 0.1 to ⁵ m ³ / min, and the injection pressure may be set to 0.1 to 1.0 MPa, for example.

  In this blasting process, not only the substrate 3 but also the resist pattern 60 is removed from the surface by the particles D. For this reason, as shown in FIGS. 6A to 6D, as the blast processing time advances, the step shape of the resist pattern 60 approaches a uniform slope shape, and the contact area between the resist pattern and the substrate 3 is reduced. I will do it. The resist pattern 60 has the highest step shape in the central region, the height perpendicular to the base 3, and the resist pattern 60 remains for a long time as it approaches the central region. By performing blasting using the resist pattern 60 as a mask, it is possible to easily form a protrusion having a concave curved surface as shown in FIG.

  In this blasting process, the removal rate of the substrate 3 and the resist pattern 60 can be adjusted by adjusting the jet flow rate and jet pressure. Thus, by adjusting the balance of the removal rate of the substrate 3 and the resist pattern 60, the protruding portion can be formed in a form different from the form shown in FIG. For example, the pin 1 having a cross section as shown in FIGS. 3A and 3B can be formed. Further, as shown in FIG. 7A, it is possible to form a protrusion having a plurality of steps on the side surface in which convex curved surfaces and concave curved surfaces are arranged alternately and continuously. As shown in b), it is also possible to form a pin having a step only on the lower part joined to the base.

  In this blasting process, the degree of surface roughness of the side surface of the pin 1 can be adjusted by adjusting the type and spraying speed of the particles P. Further, the side surface 4 of the pin 1 has a different surface direction (for example, a vector direction perpendicular to the surface) depending on the portion. For this reason, in the pin 1, the direction in which the particles P for blasting collide differs depending on the portion. According to the manufacturing method of the present embodiment, the surface roughness of the side surface 4 of the pin 1 can be made different at different portions.

  Next, after removing the residual resist after blasting, the protruding portion formed on the base 3 is polished (step S112). First, for example, a brush made of nylon fiber or the like or a wiping cloth made of urethane resin is used to polish the entire protruding portion of the base 3. In this polishing, polishing is performed using a slurry in which diamond abrasive grains (particle diameter of several to several tens of μm) are mixed with polishing oil (actually olive oil). Thereafter, the tops of the plurality of protrusions provided on the base 3 are polished, and the top surfaces 1a of the protrusions are set on the same plane. At this time, for example, using the same slurry as described above, a lapping method (a method of polishing while pressing the polishing surface through a grinding flow onto a surface plate called a lapping surface plate with a flatness of 1 μm or less) Just do it. According to such a manufacturing method, a pin having a desired shape can be formed only by performing a single blasting process, and a sample holder having a plurality of pins having a desired shape is manufactured at a relatively low cost. can do.

  During the blasting process, the surface of the protrusion is covered with a crushed layer formed by physical impact in blasting. In this polishing step, when the top of the protruding portion is polished, particularly the crushing layer near the top is removed at the same time. Thereby, in the state after this polishing step, the convex curved surface portion 4a that continues to the periphery of the top surface 1a is satisfactorily formed on the side surface 4 that continues from the top surface 1a of the protruding portion. In addition, the side close to the base 3 of the side surface 4 of the protruding portion (pin 1) is provided with a concave curved surface portion 4b, and the joint portion with the main surface 3a of the base 3 is sufficiently wide compared to the area of the top surface 1a. ing. For this reason, the bonding strength between the pin 1 and the substrate 3 is relatively high, and even when an external force is applied to the protrusion 1 in this polishing process, the pin 1 is prevented from falling off. Moreover, since there is no comparatively large level | step difference in the side surface 4, even when buffing etc. are implemented, it is suppressed that a specific location (for example, level | step-difference part) applies a stress by buffing. Further, for example, even in a protruding portion having a plurality of steps in which convex curved surfaces and concave curved surfaces are alternately and continuously arranged as shown in FIG. 7A, a plurality of forces are applied to the protruding portions during polishing. Therefore, the force is not applied concentratedly on the specific concave curved surface, and damage to the protruding portion is suppressed.

In addition, the said base | substrate 3 may be polygonal shape etc., and it does not specifically limit about a shape. The material of the substrate 3 is not particularly limited, but is formed from a ceramic sintered body or the like, and in particular, an alumina sintered body, an yttria sintered body, a YAG sintered body, a silicon nitride sintered body, a silicon carbide sintered body, or the like. It is preferable that it is a ligature. Moreover, it is preferable that especially the surface layer part of the base | substrate 3 is comprised by the single crystal or the amorphous. In the case of a single crystal or amorphous material, the surface roughness after blasting can be made relatively small, and particles can be prevented from staying on minute irregularities on the side surface of the pin.
Moreover, the sample holder used for a plasma processing apparatus etc. needs to have a plasma-resistant characteristic. In this case, it is preferable to use a yttria sintered body, an alumina sintered body, or a YAG sintered body.

  Although the sample holder of the present invention has been described above, the present invention is not limited to the above embodiments, and various modifications and changes may be made without departing from the scope of the present invention. .

It is a schematic sectional drawing explaining the structure of the wafer chuck which is one of the embodiments of the sample holder of this invention. FIG. 2 is a cross-sectional view illustrating a plurality of pins provided on the wafer chuck shown in FIG. 1. (a) And (b) is an example of the cross-sectional shape of the pin of a sample holder, respectively, and has shown cross-sectional shape different from the pin shown in FIG. It is a flowchart of the manufacturing method of the sample holder of this embodiment. It is a schematic sectional drawing explaining the manufacturing method of the sample holder of this embodiment. It is a schematic sectional drawing which shows the shape change in the blasting process of the manufacturing method of the sample holder of this embodiment. It is a schematic sectional drawing which shows the other example of the shape of the protrusion part formed by the manufacturing method of the sample holder of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pin 3 Base | substrate 3a Main surface 4 Side surface 4a Convex curved surface part 4b Concave curved surface part 5 Boundary 7 Lower end 12 Recessed part 15 Seal wall 15a Top surface 20 Wafer chuck 40 Resist layer 50 Semiconductor wafer 60 Resist pattern

Claims (5)

A sample holder having a base and a protrusion provided on one main surface of the base,
The protruding portion has a protruding end surface substantially parallel to the one main surface,
A side surface that continues from the protruding end surface to the one main surface,
A convex curved surface portion that continues to the periphery of the protruding end surface, and a concave curved surface portion that continues from the convex curved surface portion to the one main surface,
The distance from the parallel plane to the one principal surface is made larger than the distance from the top surface to the plane parallel to the one principal surface through the boundary between the convex curved surface portion and the concave curved surface portion. A sample holder. A cutting line by a plane passing through the center line of the protruding end surface and perpendicular to the one principal surface is
2. The sample holder according to claim 1, wherein the inclination increases as it approaches the protruding end surface from the one main surface.   The sample holder according to claim 1, wherein the one main surface of the base body is formed of a surface of a single crystal layer.   The sample holder according to claim 3, wherein the single crystal layer is provided on a surface of a base portion made of a silicon carbide sintered body. A sample holder having a base and a protrusion provided on one main surface of the base,
The protruding portion has a protruding end surface substantially parallel to the one main surface,
A sample holder comprising a plurality of step regions in which convex curved surfaces and concave curved surfaces are alternately and continuously arranged on a side surface continuous from the protruding end surface to the one main surface.

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