Sample holder

Abstract

To increase thermal uniformity in a sample holding tool.SOLUTION: A sample holding tool includes a ceramic substrate, a heating resistor, a first metal plate, and a fixing member. The ceramic substrate has a first surface and a second surface located opposite to the first surface. The heating resistor is located inside the ceramic substrate or on the second surface. The first metal plate has a third surface facing the second surface and a fourth surface located opposite to the third surface. The fixing member has a first end and second ends located opposite to the first end, the first end is connected to the ceramic substrate, and the fixing member fixes the ceramic substrate and the first metal plate. The fixing member also has: a first portion including the first end and extending from the ceramic substrate toward the first metal plate; a plurality of second portions each including the second end and extending from the first metal plate toward the ceramic substrate; and a third portion joining between the first portion and the plurality of second portions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to sample holders, such as wafer heating devices. [Background technology]

[0002] A known example of a sample holder is the heater unit described in Patent Document 1. The heater unit described in Patent Document 1 includes a heating element, a heater substrate that houses the heating element and has a heating surface on its upper surface, a metal container that is positioned separately from the lower surface of the heater substrate and reflects heat from the heating element, a heater substrate support that fixes the heater substrate and the metal container, and a container support that fixes the metal container to an apparatus stand. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-235672 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a heater unit, heat from the heating element is transferred to the heater substrate, heater substrate support substrate, metal container, and then container support. When the heater substrate support is simply linearly shaped, heat is less likely to remain between the heater substrate and the metal container. Furthermore, the large temperature difference between the area where the heater substrate support is present and the area where it is not present creates a temperature difference between the heater substrate and the metal container. The current sample holder is required to have minimal thermal conductivity and excellent thermal uniformity between the heater substrate and the metal container. [Means for solving the problem]

[0005] The sample holder of the present disclosure includes a ceramic substrate, a heating resistor, a first metal plate, and a fixing member. The ceramic substrate has a first surface and a second surface opposite the first surface. The heating resistor is located inside the ceramic substrate or on the second surface. The first metal plate has a third surface opposite the second surface and a fourth surface opposite the third surface. The fixing member has a first end and a second end opposite the first end, and the first end is connected to the ceramic substrate and fixes the ceramic substrate and the first metal plate. The fixing member also has a first portion including the first end and extending from the ceramic substrate toward the first metal plate, a plurality of second portions including the second end and extending from the first metal plate toward the ceramic substrate, and a third portion connecting the first portion and the plurality of second portions. Furthermore, the third portion has a plurality of fourth through holes, and the plurality of second portions each have a first recess, and are provided with a third fastening member that passes through the fourth through holes and is at least partially located in the first recess, fastening the third portion and the second portion, and are further provided with a second elastic member between the surface of the third portion facing the second surface and the third fastening member. [Effects of the Invention]

[0006] A sample holder according to one embodiment of the present disclosure has little thermal shrinkage and excellent thermal uniformity. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a cross-sectional view showing an example of a sample holder. [Figure 2] FIG. 2 is an enlarged cross-sectional view of a portion A of the sample holder shown in FIG. [Figure 3] FIG. 10 is an enlarged cross-sectional view showing another example of the sample holder. [Figure 4] FIG. 10 is an enlarged cross-sectional view showing another example of the sample holder. [Figure 5] FIG. 10 is an enlarged cross-sectional view showing another example of the sample holder. [Figure 6] FIG. 6 is an enlarged cross-sectional view of a portion B of the sample holder shown in FIG. [Figure 7] FIG. 10 is a plan perspective view showing another example of the sample holder. [Figure 8] FIG. 10 is an enlarged cross-sectional view showing another example of the sample holder. DETAILED DESCRIPTION OF THE INVENTION

[0008] The sample holder 100 will now be described in detail.

[0009] 1 is a cross-sectional view showing an example of a sample holder 100. As shown in FIG. 1, the sample holder 100 includes a ceramic substrate 1, a heating resistor 2, a first metal plate 3, and a fixing member 4.

[0010] The ceramic substrate 1 is a member of the sample holder 100 for holding a sample. The ceramic substrate 1 has a first surface 11 and a second surface 12 located opposite the first surface 11. In FIG. 1, the first surface 11 is the sample holding surface. The ceramic substrate 1 has, for example, a disk shape. Examples of materials for the ceramic substrate 1 include silicon carbide. The dimensions of the ceramic substrate 1 are, for example, a thickness of 0.5 to 10 mm and a diameter of 100 to 450 mm. The ceramic substrate 1 may have, for example, an electrode for electrostatic adsorption inside.

[0011] The heating resistor 2 is a member for heating the sample in the sample holder 100. In the drawing, the heating resistor 2 is located on the second surface 12 of the ceramic substrate 1, but the heating resistor 2 may also be located inside the ceramic substrate 1. The heating resistor 2 may be, for example, a linear member extending in the circumferential direction of the ceramic substrate 1. The heating resistor 2 may be located in multiple regions, which allows the temperature of the heating resistor 2 to be adjusted for each region. Furthermore, for example, the heating resistor 2 may be repeatedly folded along the circumferential direction of the ceramic substrate 1.

[0012] The heating resistor 2 may be made of a metal material such as silver, copper, gold, palladium, or silver-palladium. In addition to the above metal materials, the heating resistor 2 may contain, for example, a glass component. The heating resistor 2 has, for example, a thickness of 0.01 to 3 mm, a width of 0.5 to 30 mm, and a length of 100 to 5000 mm.

[0013] The first metal plate 3 is a member for supporting the ceramic substrate 1 via the fixing member 4. The first metal plate 3 has a third surface 31 facing the second surface 12 of the ceramic substrate 1 and a fourth surface 32 located opposite the third surface 31. The first metal plate 3 is located away from the ceramic substrate 1. As shown in FIG. 1 , a support member for fixing the sample holder 100 to an external device is located on the fourth surface 32. The first metal plate 3 is, for example, a disk-shaped member. In the case of an electrostatic chuck, the space between the second surface 12 and the third surface 31 is a vacuum region, and the fourth surface 32 is the portion exposed to the atmosphere.

[0014] The first metal plate 3 may be made of a metal material such as stainless steel, aluminum, or iron. When the first metal plate 3 is disk-shaped, the first metal plate 3 has a diameter of 100 to 450 mm and a thickness of 0.5 to 20 mm. The distance between the second surface 12 of the ceramic substrate 1 and the third surface 31 of the first metal plate 3 is, for example, 5 to 150 mm.

[0015] The fixing member 4 is a member for fixing the ceramic substrate 1 and the first metal plate 3. The fixing member 4 is located between the ceramic substrate 1 and the first metal plate 3. The fixing member 4 is, for example, a circular or square rod-shaped member. The fixing member 4 has a first end 401 and a second end 402. The first end 401 of the fixing member 4 is connected to the ceramic substrate 1. The second end 402 of the fixing member 4 is located opposite the first end 401 and is connected to the first metal plate 3. In FIG. 2, the first end 401 is located at the top and the second end 402 is located at the bottom.

[0016] The fixing member 4 may be made of a metal material such as stainless steel, aluminum, iron, etc. When the fixing member 4 is in the shape of a circular rod, for example, the diameter is 1 to 10 mm and the length is 5 to 150 mm.

[0017] The fixing member 4 has three parts: a first part 41, a second part 42, and a third part 43. The first part 41 extends from the ceramic substrate 1 toward the first metal plate 3. The second part 42 extends from the first metal plate 3 toward the ceramic substrate 1. Note that this description merely describes the first part 41 and the second part 42 as extending in a direction away from the connected side because they are fixing parts. Also, as shown in FIG. 1, there are multiple second parts 42. FIG. 2 illustrates a case where there are two second parts 42. The third part 43 is a part that connects the first part 41 and the multiple second parts 42. The fixing member 4 has the first part 41, the multiple second parts 42, and the third part 43 that connects them; that is, the fixing member 4 is branched. This lengthens the path along which heat from the fixing member 4 travels within the region between the ceramic substrate 1 and the first metal plate 3, making it easier for the heat from the heating resistor 2 to remain within the fixing member 4 and its surroundings. Furthermore, the configuration of this embodiment reduces the risk of heat from the heating resistor 2 being transferred to the first metal plate 3 via the fixing member 4 and escaping to the outside, compared to when the ceramic substrate 1 and the first metal plate 3 are fixed together only by a linear member such as the first portion 41. Furthermore, the temperature difference between the location where the fixing member is present and the location where the fixing member is not present is smaller than when the sample holder 100 is fixed together only by a linear member such as the first portion 41. As a result, the sample holder 100 exhibits less heat loss and excellent thermal uniformity.

[0018] The fixing member 4 is described as "having a first portion 41, a second portion 42, and a third portion 43" and "connecting each of them together," but the first portion 41 and the third portion 43, the second portion 42 and the third portion 43, and the first portion 41, the second portion 42, and the third portion 43 may all be formed from a single member.

[0019] For example, screws can be used to fasten the fixing member 4 to the ceramic substrate 1. A screw hole may be formed in the first metal plate 3, and the tip of the second end 402 of the fixing member 4 may be shaped like a screw and fitted into the screw. Another bonding method is, for example, a method using a bonding material. Examples of materials that can be used as the bonding material include silver solder and silver-copper solder.

[0020] 3 , the ceramic substrate 1 may have a first through hole 13, a first portion 41 having a second through hole 411, and a third portion 43 having a third through hole 433, and may include a first fastening member 5 inserted through each of the first through hole 13, the second through hole 411, and the third through hole 433. Here, "inserting" means that the first fastening member 5 penetrates the first portion 41 and the third portion 43, and passes through each of the second through hole 411 and the third through hole 433.

[0021] The first fastening member 5 is a rod-shaped member. The first fastening member 5 is, for example, a circular rod. The end of the first fastening member 5 located near the ceramic substrate 1 extends to the first surface 11 of the ceramic substrate 1, for example. The first fastening member 5 is a member for fixing the ceramic substrate 1 to the first portion 41 of the fixing member 4. The end of the first fastening member 5 located near the ceramic substrate 1 may have a plate-like structure facing the first surface 11 of the ceramic substrate 1. In this case, the shape is, for example, a disk-like. The first fastening member 5 may be made of a metal material such as stainless steel, aluminum, or iron. When the first fastening member 5 is rod-shaped, for example, the diameter is 1 to 10 mm and the length is 5 to 150 mm. When the end of the first fastening member 5 located near the ceramic substrate 1 is disk-shaped, the diameter is 1 to 20 mm and the thickness is 0.5 to 10 mm.

[0022] The first through hole 13, the second through hole 411 and the third through hole 433 are shaped like a circle, a square, etc. When the first through hole 13, the second through hole 411 and the third through hole 433 are each circular, the diameter is 1 to 10 mm.

[0023] The second fastening member 6 is a member for fastening the fixing member 4 and the ceramic substrate 1. As shown in FIG. 3, the second fastening member 6 is located below the third portion 43 and is connected to the first fastening member 5. The second fastening member 6 may be, for example, cup-shaped, with the first fastening member 5 passing through it. The second fastening member 6 may also be made of a metal material such as stainless steel, aluminum, or iron. When the second fastening member 6 is cup-shaped, for example, it has a diameter of 1 to 20 mm and a length of 1 to 10 mm.

[0024] The first elastic member 7 is a member that adjusts the fastening between the first fastening member 5 and the ceramic substrate 1 by dispersing the axial force of the first fastening member 5 or preventing loosening. As shown in FIG. 3 , the first elastic member 7 is located between the second fastening member 6 and the third portion 43 of the fixing member 4. The first elastic member 7 has, for example, a spring-like shape. The first elastic member 7 may be made of a metal material such as stainless steel, aluminum, or iron. When the first elastic member 7 has a spring shape, the diameter is 1 to 20 mm and the length is 1 to 20 mm. The presence of the first elastic member 7 allows the fixing member 4 to move by the elastic force when the ceramic substrate 1 thermally expands due to the heating resistor 2, thereby alleviating the stress applied to the first portion 41. As a result, the sample holder 100 has excellent durability.

[0025] As a method for fixing the first fastening member 5 and the second fastening member 6, for example, there is a method for fixing them using screws, or there is a method for fixing them by forming parts of the first fastening member 5 and the second fastening member 6 into screws and screw holes, respectively.

[0026] 4, the third portion 43 may have a plurality of fourth through holes 434, and the plurality of second portions 42 may each have a first recess 421. Also, a third fastening member 8 may be provided that passes through each of the fourth through holes 434 and the first recess 421 and fastens the third portion 43 and the second portion 42. Also, a second elastic member 9 may be provided between the third portion 43 and the second portion 42.

[0027] The shape of the fourth through hole 434 is circular, rectangular, etc. When the fourth through hole 434 is circular, the diameter of the fourth through hole 434 is 1 to 10 mm.

[0028] 4, the first recess 421 is located at one of the two ends of the fixing member 4 that is closer to the second portion 42. The first recess 421 has, for example, a circular or rectangular shape when seen from above in a perspective view of the ceramic substrate 1. When the first recess 421 is circular, the dimensions of the first recess 421 are a diameter of 1 to 10 mm and a depth of 1 to 20 mm.

[0029] The third fastening member 8 is a member for fixing the second portion 42 and the third portion 43 together. As shown in FIG. 4, the third fastening member 8 is inserted through the fourth through-hole 434 and the first recess 421. Here, "inserted" means that the third fastening member 8 passes through the third portion 43 and is positioned in the first recess 421. The third fastening member 8 has, for example, a screw shape. The third fastening member 8 may be made of a metal material such as stainless steel, aluminum, or iron. When the third fastening member 8 has a screw shape, the dimensions of the third fastening member 8 are a diameter of 1 to 10 mm and a length of 1 to 20 mm.

[0030] The second elastic member 9 is a member that strengthens the fixation between the third portion 43 and the third fastening member 8. As shown in FIG. 4, the second elastic member 9 is located between the surface of the third portion 43 that faces the second surface 12 and the third fastening member 8. The shape of the second elastic member 9 may be, for example, a spring washer. The second elastic member 9 has a spring washer-like shape. The second elastic member 9 may be made of a metal material such as stainless steel, aluminum, or iron. When the second elastic member 9 has the shape of a spring washer, the dimensions of the second elastic member 9 are a diameter of 1 to 10 mm and a thickness of 1 to 10 mm. The provision of the second elastic member 9 prevents loosening of the fixation between the second portion 42 and the third portion 43 due to repeated heating and cooling cycles over a long period of time. As a result, the sample holder 100 has excellent durability.

[0031] The first metal plate 3 may also have a second recess 33. As shown in Figures 5 and 6, the third surface 31 has the second recess 33. The second recess 33 is provided so that the second end 402 of the fixing member 4 fits therein.

[0032] The second recess 33 may have a circular or rectangular shape. When the second recess 33 is circular, the diameter of the second recess 33 is 1 to 20 mm. The second recess 33 may also have a shape similar to a screw hole. Positioning the second end 402 within the second recess 33 allows the fixing member 4 to be fitted into the first metal plate 3. This reduces the risk of the fixing member 4 and the first metal plate 3 becoming separated. As a result, the sample holder 100 has excellent durability. Accordingly, for example, the second recess 33 may have a female thread and the third fastening member 8 has a male thread, thereby further firmly fixing the third fastening member 8 to the second portion 42.

[0033] 5 and 6, the first end 401 may be connected to the ceramic substrate 1, and the second end 402 may be located between the third surface 31 and the fourth surface 32 of the first metal plate 3. In other words, the fixing member 4 may not penetrate the first metal plate 3. This makes it possible to further reduce heat loss from the portion of the fixing member 4 that penetrates and protrudes from the first metal plate 3 when the sample holder 100 is in use, compared to a structure in which the fixing member 4 penetrates the first metal plate 3.

[0034] Furthermore, as shown in FIG. 6 , the fixing member 4 may have equal distances between the first portion 41 and the second portions 42 in an enlarged cross-sectional view. In FIG. 6 , the distances between the first portion 41 and the second portions 42 are indicated by X and Y, respectively. Here, "equal distances between the first portion 41 and the second portions 42" refers to the case where X and Y are equal. In FIG. 6 , the center lines of the first portion 41 and the second portions 42 are depicted by dashed lines for ease of understanding. The distances between the first portion 41 and the second portions 42 here refer to the distances from their respective centers. Having equal distances between the first portion 41 and the second portions 42 in an enlarged cross-sectional view allows for even distribution of heat transferred to the fixing member 4. This reduces the risk of uneven heat dissipation from the fixing member 4. As a result, the sample holder 100 has excellent thermal uniformity. The distances X and Y between the first portion 41 and the plurality of second portions 42 are, for example, 1 to 20 mm.

[0035] Fig. 7 is a planar perspective view seen toward the first surface 11 of the ceramic substrate 1. For ease of understanding, in Fig. 7, the concentric lines of the first metal plate 3 are shown by dashed lines.

[0036] 7, in a planar perspective view, the fixing member 4 may have an equal distance between the first portion 41 and the plurality of second portions 42. Here, the distance between the first portion 41 and the second portion 42 is the distance from their respective centers. In FIG. 7, the second portion 42 is depicted by a two-dot chain line for ease of understanding. By having an equal distance between the first portion 41 and the plurality of second portions 42, the heat transferred to the fixing member 4 can be evenly dispersed. This reduces the risk of uneven heat dissipation from the fixing member 4. As a result, the sample holder 100 has excellent thermal uniformity.

[0037] Furthermore, a plurality of fixing members 4 may be positioned concentrically at equal intervals on the first metal plate 3. This makes it possible to disperse stress generated between the ceramic substrate 1 and the fixing members 4 when the ceramic substrate 1 thermally expands in the radial direction, compared to when the fixing members 4 are not positioned at equal intervals on concentric circles around the first metal plate 3. As a result, the sample holder 100 has excellent durability.

[0038] 8, a second metal plate 10 may be provided between the ceramic substrate 1 and the first metal plate 3, facing the second surface 12. The second metal plate 10 has a fifth surface and a sixth surface that face the second surface 12 of the ceramic substrate 1 and the third surface 31 of the first metal plate 3, respectively. The second metal plate 10 is located away from the ceramic substrate 1. The second metal plate 10 may be, for example, a disk-shaped member.

[0039] The second metal plate 10 may be made of a metal material such as stainless steel, aluminum, or iron. When the second metal plate 10 is disk-shaped, the dimensions of the second metal plate 10 are, for example, 100 to 450 mm in diameter and 1 to 10 mm in thickness. The distance between the second surface 12 of the ceramic substrate 1 and the fifth surface of the second metal plate 10 is, for example, 5 to 150 mm.

[0040] The provision of the second metal plate 10 makes it possible to reflect the radiant heat of the heating resistor 2. This allows the heat of the heating resistor 2 to be used efficiently to heat the sample.

[0041] Furthermore, an elastic member may be further provided between the second surface 12 of the ceramic substrate 1 and the first portion 41. By providing the elastic member, when the ceramic substrate 1 thermally expands due to the heating resistor 2, the fixing member 4 can move by the amount of the elastic force, thereby alleviating the stress applied to the first portion 41. As a result, the sample holder 100 has excellent durability.

[0042] Furthermore, when the first portion 41 and the third portion 43 are fixed by separate members, an elastic member may be provided between the first portion 41 and the third portion 43. This makes it possible to reduce the concentration of stress caused by thermal expansion of the first portion 41 and the third portion 43 when the fixing member 4 thermally expands.

[0043] In addition, the specific details of the configuration, structure, positional relationship, shape, etc. shown in the above embodiment can be appropriately changed without departing from the spirit of the present disclosure. Furthermore, the configuration, structure, positional relationship, and shape shown in the above embodiment can be appropriately combined without departing from the spirit of the present disclosure. [Explanation of symbols]

[0044] 1: Ceramic substrate 11: 1st page 12:Second side 13: First through hole 2: Heating resistor 3: 1st metal plate 31:Side 3 32:Side 4 33: Second recess 4: Fixing member 401: 1st end 402: 2nd end 41: Part 1 411: Second through hole 42:Second part 421: First recess 43: 3rd part 433: Third through hole 434: 4th through hole 5: First fastening member 6: Second fastening member 7: First elastic member 8: Third fastening member 9: Second elastic member 10:Second metal plate 100: Sample holder

Claims

1. A ceramic substrate; A heating resistor; A first metal plate; a fixing member; the ceramic substrate has a first surface and a second surface opposite the first surface; the heating resistor is located inside the ceramic substrate or on the second surface, the first metal plate has a third surface facing the second surface and a fourth surface positioned opposite the third surface, The fixing member has a first end and a second end opposite the first end, the first end is connected to the ceramic substrate; the ceramic substrate and the first metal plate are fixed together, The fixing member is a first portion including the first end and extending from the ceramic substrate toward the first metal plate; a plurality of second portions including the second end and extending from the first metal plate toward the ceramic substrate; a third portion connecting the first portion and the plurality of second portions; the third portion has a plurality of fourth through holes; each of the second portions has a first recess; a third fastening member that passes through the fourth through hole, at least a portion of which is located in the first recess, and fastens the third portion and the second portion together; The sample holder further comprises a second elastic member between the third fastening member and a surface of the third portion facing the second surface.

2. the ceramic substrate has a first through hole; the first portion has a second through hole; the third portion has a third through hole, a first fastening member inserted through each of the first through hole, the second through hole, and the third through hole; and a second fastening member fastening the ceramic substrate and the fixing member together with the first fastening member, 2. The sample holder according to claim 1, further comprising a first elastic member between the second fastening member and the third portion.

3. the first metal plate has a second recess; 3. The sample holder according to claim 1, wherein the second end is located within the second recess.

4. 4. The sample holder according to claim 1, wherein the fixing member has equal distances between the first portion and each of the plurality of second portions in a planar perspective view viewed toward the first surface of the ceramic substrate.

5. 5. The sample holder according to claim 1, wherein a plurality of said fixing members are positioned at equal intervals on said first metal plate in a concentric circle pattern.

6. The first elastic member has a spring, 3. The sample holder of claim 2, wherein the second resilient member comprises a spring washer.

7. A sample holder as described in claim 2, wherein the second fastening member has a cup shape that covers at least a portion of the first elastic member.

8. A sample holder described in any one of claims 1 to 7, having a second metal plate between the ceramic substrate and the first metal plate.

9. A sample holder as described in claim 3, wherein the second recess is a screw hole and is fastened to the second portion within the second recess.

Images