JPH0313703B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an apparatus for cooling a substrate such as a silicon wafer used in the manufacture of semiconductors.

(Prior art) Generally, when ion implantation or other processing is performed on this type of substrate in a vacuum chamber, there is a risk of heat generation and damage to the substrate, so it is recommended to hold the substrate in a substrate holder with circulating cooling water. It is being done. In this case, the substrate deforms due to heat and loses contact with the substrate holder, deteriorating cooling performance. Therefore, a thin film of fluorine-based resin is provided on the surface of the substrate holder to cover the silicone rubber cushion, and the substrate is placed on this thin film. By bringing them into contact with each other, even if the substrate is deformed, it can be cooled without separating.

(Problems to be Solved by the Invention) Silicon rubber has the drawback that its elasticity is lost over time under actual usage conditions, and it becomes unable to follow the deformation of the substrate. In addition, when large currents and high voltages are used to process the substrate, the substrate generates a lot of heat, and the heat flux decreases.
When it reaches 1W/ ^cm2 , the contact heat transfer coefficient, thermal conductivity,
It becomes difficult to use silicone rubber covered with fluorine-based resin, which has poor heat resistance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly durable cooling device that is suitable for cooling substrates processed under conditions that generate a large amount of heat.

(Means for Solving the Problems) In the present invention, in a device in which a substrate to be processed in a vacuum chamber is held by a substrate holder cooled by circulation of cooling water, etc., the substrate in contact with the substrate is The above objective was achieved by planting a large number of thermally conductive fine wires whose elasticity was adjusted through shape processing on the surface of the holder so that the apparent shore hardness was comparable to that of silicone rubber. .

(Function) The substrate is held on the surface of a substrate holder and subjected to treatments such as ion implantation in a vacuum chamber. However, since a large number of wires are planted so that the apparent shore hardness is comparable to that of soft silicone rubber, the amount of heat generated during processing of the substrate is transmitted to the cooled substrate holder via the thin wires, and the substrate is cooled. At the same time, each thin wire comes into contact with the substrate in accordance with the deformation of the substrate, resulting in good cooling performance.

(Example) To explain the example of the present invention with reference to the drawings, the first example is as follows.
In the figure, reference numeral 1 indicates a substrate holder placed in a vacuum chamber 2, and the substrate holder 1 is made of, for example, Cu, Al, etc.
The cooling water circulation path 3 is provided inside the metal. 4 is Cu, Al, C, with high thermal conductivity implanted on the surface of the substrate holder 1, that is, the cooling surface.
A thin wire made of metal fiber such as Mo, whose elasticity is adjusted by shape processing, and by adjusting the material, dimensions, planting density, shape, etc. of the thin wire 4, the apparent shore hardness of the entire thin wire group 4a is made of soft silicone. It is planted at the same level as the rubber. In addition, as a shape processing for adjusting the elasticity of the thin wire 4, it is possible to process the shape into a coil shape or a meandering shape.
5 indicates a substrate such as a gallium arsenide wafer or a silicon wafer to be processed, and the substrate 5 is directly or secondly processed.
As shown in the figure, the thin wire group 4a is in contact with the thin wire group 4a through the thin film 6, and the heat generated in the substrate 5 during processing is absorbed by the thin wire group 4a.
is transmitted to the cooled substrate holder 1 via a,
The substrate 5 is cooled to prevent thermal cracking. As the thin film 6, a fluororesin film is used in a range where the heat flux is low, and a flexible material with good thermal conductivity and good vacuum properties is used in a range where the heat flux is high.

(Effect of heat generation) According to the present invention, a large number of thin wires with good thermal conductivity whose elasticity is adjusted by shape processing are implanted on the surface of the substrate holder so that the shore hardness is comparable to that of silicon rubber. This allows the substrate and each thin wire to be brought into contact with each other without applying strong mechanical force, and a large heat flux can be transmitted from the substrate to the substrate holder, making it possible to efficiently cool substrates that are prone to thermal deformation and thermal cracking. It has a good effect.

[Brief explanation of the drawing]

FIG. 1 is a cut-away side view of an embodiment of the present invention, and FIG. 2 is a cut-away side view of a main part of a modification thereof. 1...Substrate holder, 2...Vacuum chamber, 4...Thin wire, 4a
...Thin wire group, 5...Substrate.

Claims (1)

[Claims] 1. In a device in which a substrate to be processed in a vacuum chamber is held by a substrate holder cooled by circulation of cooling water, the elasticity of the surface of the substrate holder that contacts the substrate is adjusted by shape processing. A cooling device for a substrate characterized by having a large number of thin wires with good thermal conductivity planted so that the apparent shore hardness is comparable to that of silicone rubber.