JP6605947B2 - Sample holder - Google Patents

Description

  The present invention relates to a sample holder used for heating a wafer.

  As a sample holder, for example, a heat equalizing plate described in JP-A-2001-237166 (hereinafter also referred to as Patent Document 1) is known. The soaking plate described in Patent Document 1 is used as a wafer heating device by being combined with a support that supports the soaking plate. One main surface of the soaking plate is a mounting surface on which the wafer is placed, and a heating resistor is formed on the other main surface. The heat equalizing plate is fixed by being pushed up from the support side by an elastic body made of a coil spring provided on the center side, and held down by the elastic body made of a bolt provided on the outer peripheral side.

JP 2001-237166 A

  However, in the wafer heating apparatus described in Patent Document 1, deformation of the soaking plate may occur under a heat cycle. Thereby, there is a possibility that the soaking of the wafer is deteriorated due to a change in the distance between the soaking plate and the wafer on the surface thereof.

  The present invention has been made in view of such problems, and an object thereof is to improve the soaking property of the soaking plate (sample holder).

The sample holder of the present invention is a disc-shaped sample holder made of ceramics and having a sample holding surface on one main surface, and when one longitudinal surface is viewed, the one main surface is on the other side. a central region is convex arcuately, possess two peripheral regions is a convex arc on one side while located across the central region, the whole of the other main surface, convex arc on the other side It is characterized by being.

  According to the sample holder of one aspect of the present invention, one main surface has an arc shape that is convex on the other side, and two peripheral edges that are located across the central region and are arc shape that are convex on one side By having a region, when the sample holder is used in combination with a support, deformation of the sample holder that occurs under a heat cycle can be reduced. Specifically, when the sample holder is combined with the support, it is flattened by pushing up and deforming the arc-shaped central region convex to the other side (support side) from one side (sample). The peripheral area, which is a convex shape on the holding surface side), is pushed down from one side and deformed to be flattened. In this way, when the sample holder is combined with the support body, the deformation that occurs when thermal stress is applied under the heat cycle is reduced by preliminarily deforming the whole with external force applied. it can.

It is a longitudinal cross-sectional view which shows the sample holder of one Embodiment of this invention, and a wafer heating apparatus provided with the same. It is a graph which shows the result of having measured the flatness of the sample holding surface in the state which removed the sample holder shown in FIG. 1 from the support body. It is a graph which shows the result of having measured the thickness distribution of the sample holder shown in FIG.

  Hereinafter, a sample holder 1 according to an embodiment of the present invention and a wafer heating apparatus 10 including the same will be described. As shown in FIG. 1, the wafer heating device 10 supports the sample holder 1, the heating resistor 9 provided in the sample holder 1, and the sample holder 1 positioned below the sample holder 1. And a plurality of fasteners 3 for fixing the sample holder 1 and the support 2 to each other. The wafer heating apparatus 10 further includes a pressing member 8 positioned between the sample holder 1 and the support 2. In addition, in FIG. 1, the fastener 3 and the press member 8 are expanded and shown for convenience.

  The sample holder 1 is a member having a sample holding surface 11 on the upper surface. In the present embodiment, the entire upper surface of the sample holder 1 is the sample holding surface 11. The sample holder 1 is a disk-shaped member, for example. The sample holder 1 is made of ceramics. As the ceramic, a ceramic composed of an element having high thermal conductivity and low possibility of contaminating the wafer is preferable. Specifically, ceramics mainly composed of silicon carbide, boron carbide, boron nitride, silicon nitride, or aluminum nitride can be used. In particular, it is preferable to use silicon carbide or aluminum nitride from the viewpoint of thermal conductivity. The dimensions of the sample holder 1 can be set such that, for example, the diameter of the upper surface (sample holding surface 11) in a plan view is 200 to 500 mm and the thickness is 1 to 7 mm. In the present embodiment, the diameter when the sample holding surface 11 is viewed in plan is set to 300 mm.

  The heating resistor 9 is a member for heating a sample (held object) such as a wafer. The heating resistor 9 is provided inside or on the lower surface of the sample holder 1. In the wafer heating apparatus 10 of this embodiment, the heating resistor 9 is provided on the lower surface of the sample holder 1. The heating resistor 9 is formed in a band shape, for example. The heating resistor 9 is made of a metal material such as gold, silver, palladium, or platinum.

  The support 2 is a member for supporting the sample holder 1. The support 2 is positioned below the sample holder 1 and supports the sample holder 1. The sample holder 1 and the support 2 are fixed by a plurality of pressing members 8 and fasteners 3, respectively. For example, one pressing member 8 is provided at the center of the lower surface of the wafer heating apparatus 10, eight are provided in a circle between the center and the outer periphery, and eight are provided along the outer periphery. The pressing member 8 is made of a coil spring, for example. The fasteners 3 are provided, for example, at equal intervals in the circumferential direction on the outer peripheral side of the wafer heating apparatus 10. The sample holder 1 is fixed by being pushed up from the support 2 side by the pressing member 8 and held down to the support 2 side by a fastener 3 provided on the outer peripheral side. Thus, the deformation | transformation which arises in a soaking | uniform-heating board is reduced by pressing the sample holder 1 from an up-down direction. In FIG. 1, the force by which the pressing member 8 pushes up the sample holder 1 and the force to hold down the support 2 are indicated by white arrows.

  The fastener 3 is a member for holding the sample holder 1 to the support 2 side. In the wafer heating apparatus 10 of the present embodiment, the fastener 3 holds the sample holder 1 and the support 2 together by using the elastic force of the spring.

  Here, when the sample holder 1 of the present embodiment is viewed from the longitudinal section in a state where the sample holder 1 is detached from the support 2, a central region 12 in which one main surface has an arc shape protruding to the other side, and a central region 12 has two peripheral regions 13 which are located on both sides and are arc-shaped convex on one side. More specifically, when the sample holder 1 is viewed from the sample holding surface 11, the central region 12 is recessed and the peripheral region 13 surrounds the central region 12 and rises.

  FIG. 2 is a graph showing the result of measuring the flatness of the sample holding surface 11 with the sample holder 1 of the present embodiment removed from the support 2. The horizontal axis indicates the position on the sample holding surface 11. Specifically, the location where the value of the horizontal axis is 0 corresponds to the center position on the sample holding surface 11, and the other locations mean the distance from this center position. In the present embodiment, since the diameter of the sample holding surface 11 is 300 μm, the position where the value of the horizontal axis is 150 and the position where −150 means the end of the sample holding surface 11. The vertical axis indicates the flatness with respect to the average height position of the entire sample holding surface 11 for the purpose of relatively showing the height difference in the sample holding surface 11. Here, “flatness” is an expression used for the sake of convenience in order to clearly express the height difference depending on the portion of the sample holding surface 11. Therefore, it does not mean a tolerance with respect to some reference value that is generally used.

  As can be seen from FIG. 2, the sample holding surface 11 has an arc shape convex to the other side having a height difference of about 10 μm in the central region 12, and one side having a height difference of about 10 μm in the peripheral region 13. Convex arc shape.

  Thereby, when the sample holder 1 is used in combination with the support 2, deformation of the sample holder 1 that occurs under a heat cycle can be reduced. Specifically, when the sample holder 1 is combined with the support 2, the center region 12 that is an arc shape convex to the other side (the support 2 side) is pushed up from the other side by the pressing member 8 to be deformed. Make it flat. Further, the peripheral region 13 having a convex shape on one side (sample holding surface 11 side) is pressed down by the fastener 3 from one side and deformed to be flattened. In the sample holder 1 of the present embodiment, not only the fastener 3 that applies force in the push-down direction but also the pressing member 8 that applies force in the push-up direction is provided in the peripheral region 13. Is made larger than the force by the pressing member 8 provided in the peripheral region 13, the peripheral region 13 can be pushed down.

  In this way, when the sample holder 1 is combined with the support 2, the entire structure is flattened in a state in which it is deformed in advance by applying external force (force by the pressing rod 8 and force by the fastener 3). The deformation that occurs when thermal stress is applied under the heat cycle can be reduced.

  In addition, when the vertical cross section is viewed, it is preferable that the other main surface has an arc shape convex to the other side in a state where the sample holder 1 is removed from the support 2. When the other surface of the sample holder 1 and the support 2 are combined, the entire other main surface of the sample holder 1 has an arc shape that protrudes toward the other side. Can be pushed up easily. In particular, when the sample holder 1 and the support 2 are combined, in order to flatten the sample holding surface 11, it is necessary to strongly push up the center portion particularly from the other side in the central region 12. Since the entire other main surface of the tool 1 has an arc shape protruding to the other side, a plurality of similar pressing members 8 are disposed between the support 2 and the sample holder 1, and the central region 12 is naturally formed. The force which pushes up the sample holder 1 by the pressing member 8 can be exerted greatly in the central portion of the inside. Therefore, when the sample holder 1 is combined with the support 2, the sample holding surface 11 can be easily flattened.

Moreover, it is preferable that the sample holder 1 has the smallest thickness at the center when the longitudinal section is viewed. FIG. 3 is a graph showing the results of measuring the thickness of the sample holding surface 11 with the sample holder 1 of the present embodiment removed from the support 2. The horizontal axis indicates the position on the sample holding surface 11 as in the case of FIG. The vertical axis indicates the relative thickness of each part relative to the average thickness of the entire sample holder 1. As can be seen from FIG. 3, the sample holder 1 has a large thickness in the peripheral region 13. Moreover, in the center area | region 12, thickness becomes thin as it goes to the center. The sample holder 1 has the smallest thickness at the center. The sample holder 1 is deformed before and after being attached to the support 2, but the center of the sample holder 1 is a portion that is particularly greatly deformed. Since the center region 12 can be easily deformed by forming the center thinly, the sample holding surface 11 can be easily flattened when the sample holder 1 is attached to the support 2. .

  Further, when the longitudinal section is viewed, the width of the central region 12 on one main surface is larger than the total width of the two peripheral regions 13. By making the central region 12 wide, the pressing member 8 can be arranged in a wider range. Since the location where the pressing member 8 is attached is increased in heat absorption, it is difficult to improve the thermal uniformity when the pressing member 8 is partially biased. On the other hand, by increasing the width of the central region 12, the pressing member 8 for pushing up the central region 12 can be arranged in a wide range, so that it is easy to control heat shrinkage. As a result, the thermal uniformity on the sample holding surface 11 can be improved. The central region 12 here means a portion arcuate on the other side, and the peripheral region 13 means the entire region located on the outer peripheral side of the central region 12.

  In addition, when the pressing member 8 is provided also in the peripheral area | region 13 like this embodiment, the view that the pressing member 8 can be arrange | positioned extensively, without making the center area | region 12 wide is also considered. This is wrong. That is, when the pressing member 8 is provided in the peripheral region 13, it is necessary to always provide the pressing member 8 in consideration of the force relationship with the fastener 3. There are major limitations. Therefore, it is preferable from the viewpoint of improving thermal uniformity that the central region 12 is set in a wider range than the peripheral region 13 and the pressing member 8 is disposed in the central region 12 in a wide range.

1: Sample holder 11: Sample holding surface 12: Central region 13: Peripheral region 2: Support body 3: Fastener 8: Pressing member 9: Heating resistor 10: Wafer heating device

Claims (4)

A disk-shaped sample holder made of ceramics and having a sample holding surface on one main surface, wherein the one main surface is an arc shape convex to the other side when viewed in a longitudinal section If, possess two peripheral regions is a convex arc on one side while located across the central region, the whole of the other main surface, wherein the convex arc der Rukoto on the other side Sample holder.   A disk-shaped sample holder made of ceramics and having a sample holding surface on one main surface, wherein the one main surface has an arc shape protruding to the other side when viewed in a longitudinal section And having two peripheral regions that are located on both sides of the central region and are arcuately convex on one side, the width of the central region on the one main surface is greater than the total width of the two peripheral regions A sample holder characterized by being large. 3. The sample holder according to claim 2 , wherein, when the longitudinal section is viewed, the whole of the other main surface has an arc shape protruding to the other side. The sample holder according to any one of claims 1 to 3, wherein the sample holder has the smallest thickness at the center when the longitudinal section is viewed.

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