Ceramic heater with shaft

Abstract

The ceramic heater with shaft comprises: a ceramic plate in which a resistance heating element is embedded; a hollow ceramic shaft whose upper end is joined to the surface of the ceramic plate opposite to the chip mounting surface; and a shaft heating part embedded in the side wall on the upper end side of the ceramic shaft.

Description

Technical Field

[0001] The invention relates to a ceramic heater with a shaft. Background Art

[0002] In the past, a ceramic heater with a shaft that holds the wafer was used in micro-processing such as conveying, exposure, CVD, etc., cleaning, etching, and cutting of semiconductor wafers. As such a ceramic heater with a shaft, as shown in Patent Document 1, a ceramic heater is disclosed, which includes a ceramic plate in which a resistive heating element is embedded, a hollow ceramic shaft provided on the surface of the ceramic plate opposite to the wafer mounting surface, and a heating element power supply rod accommodated in the internal space of the ceramic shaft. The heating element power supply rod is joined to the resistive heating element from the surface of the ceramic plate opposite to the wafer mounting surface.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2007-51317 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In such a ceramic plate of a ceramic heater with an axis, the heat dissipation of the ceramic axis joint portion and other portions is different. That is, the ceramic axis joint portion has a larger heat capacity than other portions, and is therefore prone to low temperatures. Therefore, when the resistance heating element is designed in such a way that the entire ceramic plate is uniformly at a predetermined set temperature (for example, 500°C), when used at a temperature higher than the set temperature (for example, 700°C), the ceramic axis joint portion sometimes generates too much heat and becomes a high temperature, and the thermal uniformity is destroyed. On the other hand, when used at a temperature lower than the set temperature (for example, 300°C), the ceramic axis joint portion sometimes generates insufficient heat and becomes a low temperature, and the thermal uniformity is destroyed. In addition, when the ceramic plate is heated or cooled, the thermal uniformity is sometimes destroyed.

[0008] The present invention has been made to solve such a problem, and a main object of the present invention is to suppress temperature deviation between a ceramic-shaft-joining portion and other portions of a ceramic heater with a shaft.

[0009] Solutions to Solve Problems

[0010] The ceramic heater with shaft of the present invention comprises:

[0011] A ceramic plate having a resistive heating element embedded therein;

[0012] a hollow ceramic shaft, the upper end of which is joined to the surface of the ceramic plate opposite to the wafer mounting surface; and

[0013] A shaft heating portion is embedded in the side wall of the upper end side of the ceramic shaft.

[0014] In this ceramic heater with shaft, the shaft heating part embedded in the side wall of the upper end of the ceramic shaft can be controlled independently from the resistance heating element embedded in the ceramic plate. Therefore, the temperature deviation between the ceramic shaft joint part and other parts can be suppressed.

[0015] In the ceramic heater with an axis of the present invention, the ceramic axis may also have a cylindrical axis body and an insulating film covering the side surface of the upper end side of the axis body, and the axis heating portion is arranged on the side surface of the upper end side of the axis body and is buried in the ceramic axis by being covered by the insulating film.

[0016] In the spooled ceramic heater of the present invention, it is preferable that the insulating film is an aerosol deposited (AD) film or a sprayed film. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a longitudinal sectional view of the ceramic heater with shaft according to the present embodiment. DETAILED DESCRIPTION

[0018] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 It is a longitudinal sectional view of the ceramic heater with shaft according to the present embodiment.

[0019] like Figure 1 As shown, the ceramic heater with an axis comprises a ceramic plate, a ceramic axis and an axis heating part. A resistance heating element is buried in the ceramic plate. The resistance heating element is designed in such a way that the temperature of the ceramic axis joint part in the whole ceramic plate is lower than that of the other parts when power is supplied. The resistance heating element is energized via a power supply rod accommodated in the internal space of the ceramic axis. The resistance heating element can also be respectively arranged in multiple areas of the ceramic plate. The ceramic axis is a hollow axis that is joined to the surface of the ceramic plate opposite to the wafer mounting surface by direct joining. The ceramic axis has a cylindrical axis body and an insulating film covering the side surface of the upper end side of the axis body. The axis heating part is a resistance heating element buried in the side wall of the upper end side of the ceramic axis. Here, the axis heating part is arranged on the side surface of the upper end side of the axis body by printing and plating, and is buried in the ceramic axis by being covered with an insulating film (such as an aluminum oxide film). The insulating film is preferably an aerosol deposition (AD) film or a sprayed film. In particular, the AD method (including the plasma AD method) is suitable for forming a thin film of fine ceramic particles with high precision. In addition, the AD method can form a film of ceramic particles through impact solidification, so it is not necessary to sinter the ceramic particles at high temperature. The shaft heating part can be energized via a power supply rod accommodated in the internal space of the ceramic shaft, or via a power supply rod buried in the side wall of the ceramic shaft.

[0020] In the ceramic heater with shaft of the present embodiment described above, the shaft heating portion embedded in the side wall of the upper end of the ceramic shaft can be controlled independently from the resistance heating element embedded in the ceramic plate. Therefore, the temperature deviation between the ceramic shaft joint portion and other portions can be suppressed.

[0021] It should be noted that at least one of the electrostatic electrode and the RF electrode may be buried in the ceramic plate.

[0022] This application claims priority based on Japanese Patent Application No. 2019-122788 filed on July 1, 2019, the entire contents of which are incorporated herein by reference.

[0023] Possibility of Industrial Application

[0024] The present invention can be used for micro-processing such as transfer, exposure, CVD and other film forming processes, cleaning, etching, and cutting of semiconductor wafers.

Claims

1. A ceramic heater with an axis, comprising: A ceramic plate having a resistive heating element embedded therein; a hollow ceramic shaft, the upper end of which is joined to the surface of the ceramic plate opposite to the wafer mounting surface; and A shaft heating portion, which is arranged on the side wall surface of the upper end side of the ceramic shaft, The ceramic shaft includes a cylindrical shaft body and an insulating film covering a side surface of an upper end side of the shaft body. The shaft heating portion is provided on the side surface of the upper end side of the shaft body and is buried in the ceramic shaft by being covered with the insulating film. The insulating film is an aerosol deposition film formed in a manner to isolate the shaft heating portion from the outside air. The aerosol deposition film only covers the shaft heating portion provided on the side wall surface of the upper end side of the ceramic shaft. The resistance heating element embedded in the ceramic plate is designed so that when power is supplied, the portion of the ceramic plate that is joined to the ceramic shaft becomes lower in temperature than other portions. The shaft heating portion embedded in the ceramic shaft can be controlled independently of the resistance heating element embedded in the ceramic plate.

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