Alignment device, photoetching machine and alignment method

Abstract

The invention provides an alignment device, a photoetching machine and an alignment method. The illumination provided by the illumination unit is diffracted through the grating mark and generates diffracted light, and the diffracted light is divided into third diffracted light with a second polarization direction and fourth diffracted light with a first polarization direction through the light splitting unit. After the third diffraction light and the fourth diffraction light are transmitted by the first wave plate, interference occurs in the first polarization direction and the second polarization direction, and interference light is generated. And the light energy of the first polarized light and the light energy of the second polarized light in the interference light are respectively obtained by a first detector and a second detector. And when the grating mark is moved until the light energy acquired by the first detector and the light energy acquired by the second detector respectively reach a preset value, the position of the grating mark is an alignment position. Therefore, the diffraction order interference can be realized without using a self-reference interference prism, the cost is low, the operation is simple and convenient, and the alignment precision is high.

Description

technical field [0001] The present invention relates to the technical field of integrated circuit manufacturing, and in particular, to an alignment device, a lithography machine and an alignment method. Background technique [0002] In the field of integrated circuit manufacturing technology, a photolithography machine can apply a reticle pattern to a photoresist and other photosensitive film layers of a silicon wafer (also referred to as a substrate) to prepare a desired circuit structure. In order to precisely control the position on the silicon wafer corresponding to each lithography, it is necessary to set a lithography alignment mark (usually a grating mark) on the silicon wafer, and set one or more corresponding alignment devices to measure the position on the silicon wafer. The position of the corresponding lithography alignment marks is then determined to determine the alignment position of the silicon wafer. [0003] At present, the commonly used alignment device u...

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to provide an alignment device, a lithography machine and an alignment method to solve at least one of the problems of high cost of alignment measurement and low alignment accuracy

Images