Photoetching apparatus and method for improving photoetching machine overlay accuracy

Abstract

The present invention relates to a photoetching apparatus. The apparatus comprises: a photoetching machine lens, wherein the photoetching machine lens comprises a lens set formed by a plurality of lenses, and is provided for transmitting light beam emitted by the photoetching machine; a silicon slice workpiece table, wherein the silicon slice workpiece table is positioned below the lens, and is provided for placing a silicon slice; a temperature measurement system, wherein the temperature measurement system is adjunctively arranged on the silicon slice workpiece table to measure the temperature of the silicon slice workpiece table; a compensation control system, wherein the compensation control system predicts the overlay deviation of the really-etched silicon slice according to the temperature signal transmitted from the temperature measurement system and the pre-fitted functional relation of the silicon slice overlay deviation and the temperature of the silicon slice workpiece table, and controls the relative shift generated by the lens set in the photoetching machine lens in the optical axis direction to compensate the overlay deviation of the really-etched silicon slice. According to the present invention, the uniform overlay accuracy among the batches and the uniform overlay accuracy among the silicon slices are realized by the photoetching apparatus of the present invention, the structure is simple, and the versatility is good. The present invention further discloses a method for improving the photoetching machine overlay accuracy.

Description

technical field [0001] The invention relates to a photolithography device and a method for improving the alignment accuracy of the photolithography machine. Background technique [0002] During the silicon wafer photolithography process, the silicon wafer workpiece table will be heated due to the continuous irradiation of the light source of the photolithography machine. However, the temperature rise of the silicon wafer workpiece table will cause thermal deformation of the silicon wafer, which will cause the registration deviation of the silicon wafer to increase and the precision to decrease, which will lead to the gap between the silicon wafer and the silicon wafer, batch and batch in the continuous operation of the lithography machine. There is a large difference in the registration accuracy between the processes. And due to continuous exposure, the temperature is continuously accumulated, and the differences between batches and between films are always unavoidable. ...

AI Technical Summary

Problems solved by technology

However, the temperature rise of the silicon wafer workpiece table will cause thermal deformation of the silicon wafer, which will cause the registration deviation of the silicon wafer to increase and the precision to decrease, which will lead to the gap between the silicon wafer and the silicon wafer, batch and batch in the continuous operation of the lithography machine. There is a large difference in registration accuracy between processes

And due to continuous exposure, the temperature is continuously accumulated, and the differences between batches and between films are always unavoidable

[0003] During the photolithography process, it is also necessary to avoid any slight impact on the registration accuracy and possible dust pollution, and ordinary cooling measures are difficult to be practical

[0004] In this regard, a solution is to use the method of intermittently cooling the silicon wafer workpiece table during the silicon wafer exposure process to control the registration accuracy, but this will lead to a decrease in production capacity and a decrease in equipment utilization

[0005] Another solution is to set up a heat shield between the silicon wafer and the silicon wafer workpiece table, but the defect of registration accuracy reduction caused by this thermal deformation cannot be completely avoided

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