JPS62216229A - Spin chuck - Google Patents

Abstract

PURPOSE:To control the temperature of a wafer constantly by forming a gas passage, providing a venturi by contracting part of the passage, and connecting it with a vacuum hole. CONSTITUTION:A gas passage 5 is feeding temperature control gas into a body 1 is formed adjacent to a wafer supporting surface 1a, part of the passage 5 is contracted to form a venturi 5a in the lower portion of the wafer supporting surface 1a, and the venturi 1a is connected with the vacuum hole 6 of the surface 1a. Since the passage area is contracted in the venturi 5a when the gas is fed to the passage 5, a pressure difference occurs before and after the throttle to generate negative pressure in the venturi 5a. Accordingly, the back surface of a semiconductor wafer 2 disposed on the surface 1a is attracted in vacuum by the negative pressure through the hole 6 to hold the wafer 2 on the surface 1a. Thus, the temperature control of the wafer can be accurately performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a spin chuck that holds a semiconductor wafer under vacuum and applies rotational force to it during photoresist coating and development steps of photolithography.

[Prior Art] Conventionally, this type of spin chuck has a vacuum hole 4 opened in the wafer support surface 3a of the spin chuck main body 3, as shown in FIG. Pull the wafer 3 onto the wafer support surface 3a
The main body 3 is rotated by a motor (not shown) to give rotation to the semiconductor wafer 2, and the semiconductor wafer 2 is subjected to photoresist coating or development.

[Problems to be Solved by the Invention] In photoresist coating or development in the photolithography process, controlling the temperature of the wafer during processing is one of the important process conditions. If the wafer temperature changes during the photoresist coating process, the thickness of the coating film will change.
It becomes impossible to form a coating film with a desired thickness. Further, if the temperature of the wafer changes during the development process, since development is a chemical change, the reaction rate of development changes, resulting in over-development or under-development.

However, in the conventional spin chuck mentioned above, the temperature of the spin chuck itself cannot be controlled, so the wafer on the spin chuck is affected by the temperature of the spin chuck, making it impossible to control the wafer temperature at a constant level. Therefore, the thickness of the coating film fluctuates, and over-development or under-development may occur.

An object of the present invention is to provide a spin chuck that can control the temperature of a wafer at a constant level.

[Means for Solving the Problems] The present invention provides a rotatable spin chuck having a vacuum hole in a support surface for vacuum-chucking a semiconductor wafer, and a gas passageway for flowing a temperature control gas under the support surface of the spin chuck body. The spin chuck is characterized in that a venturi portion is provided by reducing the diameter of a portion of the gas passage, and the venturi portion is communicated with the vacuum hole.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, a spin chuck main body 1 has a T-shaped cross section, has a wafer support surface 1a formed on its upper surface, has a vacuum hole 6 in the support surface 1a, and is rotationally driven by a motor (not shown). The present invention provides a gas flow path 5 for flowing a temperature control gas in the spin chuck body 1 adjacent to the wafer support surface 1a, and reduces the diameter of a part of the gas flow path 5 to form a venturi portion 5a.
is formed at the lower part of the wafer support surface 1a, and the venturi portion 5
a is communicated with the vacuum hole 6 of the wafer support surface 1a.

In the embodiment, when gas is poured into the gas flow path 5, since the flow path area is reduced in diameter at the venturi portion 5a, a pressure difference is generated before and after the constricted portion, and a negative pressure is generated in the venturi portion 5a. Semiconductor wafer 2 positioned on wafer support surface 1a under negative pressure In the present invention, negative pressure is generated in venturi portion 5a with the flow of gas, and the wafer is adsorbed by the negative pressure. By adjusting the temperature of the gas flowing through the semiconductor wafer 2, the temperature of the semiconductor wafer 2 can be controlled via the wafer support surface 1a.

[Effects of the Invention] -d- As explained above, the present invention can be used in an apparatus that performs photoresist coating or development in a photolithography process, so that wafers on a spin chuck, which are difficult to use with conventional spin chucks, can be easily removed. This has the effect of making it possible to control the wafer temperature with high precision, which is one of the important process conditions in coating or developing processing.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view of a conventional spin chuck. 1... Spin chuck body 1a... Wafer support surface 2... Semiconductor wafer 5... Gas passage 5a... Venturi portion 6... Vacuum hole Fig. 1

Claims (1)

[Claims] (1) In a rotatable spin chuck having a vacuum hole on the support surface for vacuum-chucking a semiconductor wafer, a gas passage through which a temperature control gas flows is formed below the support surface of the spin chuck body, and a part of the gas passage is formed. A spin chuck characterized in that a bench lily portion is provided by reducing the diameter of the spin chuck, and the bench lily portion is communicated with the vacuum hole.