JP2016024860A - Heater unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater unit capable of improving the thermal uniformity of a heater (heater surface).SOLUTION: A heater unit 100 includes a heater 110 and a pair of electrodes 120. Each of the pair of electrodes 120 has a through-hole region 122-1 in which a through-hole 123 is provided extending along a direction intersecting with a vertical direction to a rear surface 112 of the heater 110, and the lower end BE of the through-hole portion 122-1 is provided within the range of 3 mm or more and 30 mm or less from the rear surface 112 of the heater 110.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a heater unit for heating a semiconductor wafer.

  Conventionally, a heater unit for heating a semiconductor wafer has been proposed. The heater unit includes a heater having a flat plate shape and a pair of electrodes for supplying electric power to the heater. The heater has a heater surface facing the semiconductor wafer and a back surface provided on the opposite side of the heater surface. The pair of electrodes is provided on the back side of the heater and is connected to the heater (for example, Patent Documents 1-3).

JP 2002-124364 A JP 2005-166830 A JP 2011-146290 A

  In the heater unit described above, high heat uniformity is required. As a result of intensive studies, the inventors have found that the thermal uniformity of the heater (heater surface) is hindered by heat escape from the heater to the pair of electrodes.

  Therefore, the present invention has been made to solve the above-described problem, and an object of the present invention is to provide a heater unit that can improve the heat uniformity of the heater (heater surface).

  A first feature is a heater unit for heating a semiconductor wafer, the heater unit having a heater surface facing the semiconductor wafer and a back surface provided on the opposite side of the heater surface, and disposed on the back surface side of the heater. A pair of electrodes connected to the heater, each of the pair of electrodes being provided with a through hole extending along a direction intersecting a direction perpendicular to the back surface of the heater The lower end of the through-hole portion is provided in a range of 3 mm or more and 30 mm or less from the back surface of the heater in the vertical direction.

  1st characteristic WHEREIN: In the cross section which passes along the centerline of the said through-hole site | part, the ratio for which the site | part except the said through-hole occupied with respect to the total cross section of the said through-hole site | part is 50% or more and 80% or less, The center line of the through hole portion is a straight line that passes through the center of the through hole portion in a cross section along the back surface of the heater and extends in a direction perpendicular to the back surface of the heater.

  In the first feature, each of the pair of electrodes has a constricted portion provided on the heater side with respect to the through-hole portion, and the constricted portion is in contact with the back surface of the heater. The constricted part has a cross-sectional area smaller than the cross-sectional area of the through-hole part in the cross section along the back surface of the heater.

  In the first feature, the heater and the pair of electrodes are made of silicon carbide.

  ADVANTAGE OF THE INVENTION According to this invention, the heater unit which makes it possible to improve the thermal uniformity of a heater (heater surface) can be provided.

FIG. 1 is a view showing a heater unit 100 according to the first embodiment. FIG. 2 is a diagram illustrating the heater unit 100 according to the first embodiment. FIG. 3 is a diagram showing the electrode 120 according to the first embodiment. FIG. 4 is a diagram illustrating the electrode 120 according to the first embodiment.

  Hereinafter, a heater unit according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

  However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[Outline of Embodiment]
The heater unit according to the embodiment heats the semiconductor wafer. The heater unit has a heater surface facing the semiconductor wafer and a back surface provided on the opposite side of the heater surface, and a pair of electrodes disposed on the back surface side of the heater and connected to the heater With. Each of the pair of electrodes has a portion (hereinafter referred to as a through-hole portion) provided with a through-hole extending along a direction intersecting a direction perpendicular to the back surface of the heater. A lower end of the through hole portion is provided in a range of 3 mm to 30 mm from the back surface of the heater in the vertical direction.

  In the embodiment, each of the pair of electrodes has a through hole extending along a direction intersecting with a direction perpendicular to the back surface of the heater. Accordingly, since the energization volume decreases in the through-hole portion where the through-hole is provided in the electrode, the amount of heat generated in the through-hole portion increases, and the heat escape from the heater to the through-hole portion is suppressed. The heat uniformity of the heater (heater surface) is improved by increasing the amount of heat generated in the through-hole region and suppressing heat escape.

  In addition, since the through hole extends along a direction intersecting the direction perpendicular to the back surface of the heater, the length of the through hole is shorter than the case where the through hole is formed along the direction perpendicular to the back surface of the heater. Hole processing is easy. In addition, the strength of the electrode is sufficiently maintained as compared with the case where the cross-sectional area of the electrode is reduced in the cross section along the back surface of the heater.

  Further, the lower end of the through-hole portion is provided in a range of 3 mm or more and 30 mm or less from the back surface of the heater in the vertical direction. Thus, heat escape from the heater to the electrode can be suppressed while ensuring the strength of the electrode.

[First Embodiment]
(Heater unit)
The heater unit according to the first embodiment will be described below. FIG.1 and FIG.2 is a figure which shows the heater unit 100 which concerns on 1st Embodiment. 3 and 4 are views showing the electrode 120 according to the first embodiment. FIG. 4 is a view showing a P section of the electrode 120 shown in FIG.

  1 to 4, the X direction is a direction in which the rod-shaped heater 110 extends, and the Z direction is a direction in which the rod-shaped electrode 120 extends. The Z direction can also be referred to as an up-down direction in which the upper side of the drawing is the upward direction and the lower side of the drawing is the downward direction. The Y direction is a direction orthogonal to the X direction and the Z direction, and is a direction in which a through hole 123 described later extends.

  As shown in FIGS. 1 and 2, the heater unit 100 includes a heater 110 and a pair of electrodes 120 (electrode 120A and electrode 120B). As shown in FIG. 2, the heater unit 100 heats the semiconductor wafer 10 placed on the support member 20.

  The heater 110 has a heater surface 111 facing the semiconductor wafer 10 (support member 20) and a back surface 112 provided on the opposite side of the heater surface 111. In the first embodiment, the heater 110 has a rod-like flat plate shape extending along the X direction. Heater 110 is preferably made of silicon carbide.

  Each of the pair of electrodes 120 is disposed on the back surface 112 side of the heater 110 and is connected to the heater 110. In the first embodiment, each of the pair of electrodes 120 has a rod-like columnar shape extending along the vertical direction (Z direction) with respect to the back surface 112 of the heater 110. The pair of electrodes 120 is preferably composed of silicon carbide.

  Specifically, the electrode 120 has a constricted part 121 and a main body part 122 as shown in FIGS. 3 and 4. Further, as shown in FIG. 4, the electrode 120 has a through-hole 123 extending along a direction (for example, the Y direction) intersecting the vertical direction (Z direction) with respect to the back surface 112 of the heater 110. In addition, the main body part 122 has the through-hole part 122-1 and the non-through-hole part 122-2, as shown in FIG.

  The constricted part 121 is a part provided closer to the heater 110 than the main body part 122 (through-hole part 122-1). The constricted part 121 contacts the back surface 112 of the heater 110. The constricted part 121 has a cross-sectional area smaller than the cross-sectional area of the main body part 122 (through-hole part 122-1) in the cross-section along the back surface 112 of the heater 110 (that is, the XY cross-section).

  The main body part 122 is a part that is continuous with the constricted part 121, and has the through-hole part 122-1 and the non-through-hole part 122-2 as described above. The through-hole part 122-1 is a part in which the through-hole 123 is provided, and the non-through-hole part 122-2 is a part in which the through-hole 123 is not provided.

  In 1st Embodiment, in the cross section (P cross section shown in FIG. 1) which passes along the centerline (L shown in FIG. 1) of the through-hole site | part 122-1, the through-hole 123 with respect to the total cross section of the through-hole site | part 122-1. The ratio of the portion excluding (the hatched portion shown in FIG. 4) is 50% or more and 80% or less. Note that the center line (L shown in FIG. 1) of the through-hole portion 122-1 passes through the center of the through-hole portion 122-1 in the cross section along the back surface 112 of the heater 110 and the back surface of the heater 110. 112 is a straight line extending along the vertical direction (Z direction) with respect to 112. Moreover, it is preferable that the cross section (P cross section shown in FIG. 1) passing through the center line of the through hole portion 122-1 is a cross section orthogonal to the through hole 123.

  In the cross section described above, the ratio of the portion excluding the through holes 123 to the total cross section of the through hole portions 122-1 is 50% or more, so that the strength of the electrode 120 is sufficiently maintained. On the other hand, in the cross section described above, the ratio of the portion excluding the through holes 123 to the total cross section of the through hole portions 122-1 is 80% or less, thereby increasing the heat generation amount of the through hole portions 122-1. In addition, heat escape from the heater 110 to the electrode 120 is suppressed.

  In the first embodiment, the lower end BE of the through-hole part 122-1 is provided in the range of 3 mm to 30 mm from the back surface 112 of the heater 110. Thus, heat escape from the heater 110 to the electrode 120 can be suppressed while securing the strength of the electrode 120.

  For example, when the main body part 122 has a cylindrical shape with φ10 mm, the constricted part 121 has a cylindrical shape with φ6 mm. In the direction perpendicular to the back surface 112 of the heater 110 (the Z direction shown in FIGS. 1 and 2), the length of the constricted portion 121 is 10 mm. In such a case, the through-hole 123 has a circular shape of φ2 mm in the P cross section shown in FIG. In such a case, the centers of the through holes 123 adjacent to each other are preferably 3 mm apart.

(Function and effect)
In the first embodiment, each of the pair of electrodes 120 has a through-hole 123 extending along a direction intersecting the vertical direction with respect to the back surface 112 of the heater 110. Therefore, since the energization volume decreases in the through-hole part 122-1, the amount of heat generated in the through-hole part 122-1 increases, and heat escape from the heater 110 to the through-hole part 122-1 is suppressed. The heat uniformity of the heater 110 (heater surface 111) is improved by increasing the heat generation amount of the through-hole portion 122-1, and suppressing the heat escape.

  Since the through-hole 123 extends along a direction intersecting the direction perpendicular to the back surface 112 of the heater 110, the length of the through-hole 123 is longer than the case where the through-hole is formed along the direction perpendicular to the back surface of the heater 110. The through hole 123 is easy to process. In addition, the strength of the electrode 120 is sufficiently maintained as compared with the case where the cross-sectional area of the electrode is reduced in the cross section along the back surface of the heater.

  Moreover, the lower end BE of the through-hole part 122-1 is provided in the range of 3 mm or more and 30 mm or less from the back surface 112 of the heater 110 in the vertical direction. Thus, heat escape from the heater 110 to the electrode 120 can be suppressed while securing the strength of the electrode 120.

[Evaluation results]
Hereinafter, the evaluation results will be described. Specifically, samples 1 to 5 having different positions of the lower end BE of the through-hole portion 122-1 from the back surface 112 of the heater 110 in the direction perpendicular to the back surface 112 of the heater 110 are prepared. ) Was measured, and the difference between the maximum temperature and the minimum temperature was measured. Further, the stress generated in the electrode 120 when a displacement of 0.2 mm was applied to the electrode 120 was measured.

  The results are shown in Table 1 below. In Table 1, the smaller the value of the stress generated in the electrode 120, the stronger the strength and the less the breakage.

  As shown in Table 1, it was confirmed that Samples 2 to 4 according to the present invention can suppress thermal escape. Specifically, it was confirmed that Samples 2 to 4 according to the present invention can suppress heat escape while securing the strength of the electrode 120.

[Other Embodiments]
Although the present invention has been described with reference to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the embodiment, the heater 110 has a bar-like flat plate shape extending along the X direction. However, the embodiment is not limited to this. The heater 110 may have a disk shape that extends in the XY plane.

  In the embodiment, the electrode 120 has a rod-like columnar shape extending along the vertical direction (Z direction) with respect to the back surface 112 of the heater 110. However, the embodiment is not limited to this. The electrode 120 may have a flat plate shape extending along the Z direction, or may have a polygonal column shape extending along the Z direction.

  DESCRIPTION OF SYMBOLS 10 ... Semiconductor wafer, 20 ... Support member, 100 ... Heater unit, 110 ... Heater, 120 ... Electrode, 121 ... Constricted part, 122 ... Main part, 123 ... Through-hole

Claims (4)

A heater unit for heating a semiconductor wafer,
A heater having a heater surface facing the semiconductor wafer and a back surface provided on the opposite side of the heater surface;
Arranged on the back side of the heater, and a pair of electrodes connected to the heater,
Each of the pair of electrodes has a through-hole portion provided with a through-hole extending along a direction intersecting a direction perpendicular to the back surface of the heater,
The lower end of the through-hole part is provided in the range of 3 mm or more and 30 mm or less from the back surface of the heater in the vertical direction. In the cross section passing through the center line of the through hole portion, the ratio of the portion excluding the through hole to the total cross section of the through hole portion is 50% or more and 80% or less,
The center line of the through-hole part is a straight line that passes through the center of the through-hole part in a cross section along the back surface of the heater and extends in a direction perpendicular to the back surface of the heater. The heater unit according to claim 1. Each of the pair of electrodes has a constricted part provided on the heater side with respect to the through-hole part,
The constricted part is in contact with the back surface of the heater,
2. The heater unit according to claim 1, wherein the constricted portion has a cross-sectional area smaller than a cross-sectional area of the through-hole portion in a cross section along the back surface of the heater.   The heater unit according to claim 1, wherein the heater and the pair of electrodes are made of silicon carbide.

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