Alignment device for photoetching machines and alignment method thereof

Abstract

The invention discloses an alignment device for photoetching machines and an alignment method thereof. The alignment device comprises a light source, a collimating lens, a to-be-aligned mask, a mark on the mask, and a four-quadrant light intensity sensor; and the alignment device is characterized in that the mark is nearly cruciform and symmetrical about an X axis and a Y axis, a set difference is formed between the length H of the mark in the direction of the X axis and the length L of the mark in the direction of the Y axis, and a set angle is formed between the side edge of the mark and a coordinate axis. The alignment method comprises the following steps: the collimating lens collimates and irradiates lights emitted from the light source to the mark on the mask; collimated light beam passing through the mark perpendicularly enters the four-quadrant light intensity sensor; the coordinates of the X axis and the Y axis of a current mask and the rotary angle of the current mask along the normal direction of the four-quadrant light intensity sensor are calculated according to the information of the four-quadrant light intensity sensor; and the coordinates and the angle are fed backto a mask motion system so as to carry out position moving and rotation on the mask, then a pre-alignment process is completed. The device and method provided by the invention are used for the mask pre-alignment of photoetching machines, and by using the device and method provided by the invention, the space of the mask can be saved, and the utilization rate of the mask can be increased.

Description

technical field [0001] The invention relates to the field of photolithography, and in particular to an alignment device and an alignment method for a photolithography machine. Background technique [0002] The pre-alignment technology in the lithography machine is to pre-align the mask with the optical axis of the objective lens within a certain range of accuracy, including rotation and horizontal alignment, so that the alignment marks are within the capture range of the precision alignment system, Whether the pre-alignment is successful or not and its efficiency directly affects the production efficiency. [0003] Patent CN2421670 provides a silicon wafer pre-alignment device, which is characterized by using four-quadrant detectors to collect images of two marks on the silicon wafer, and using the energy difference relationship between each quadrant to represent the position information of the silicon wafer , this device is a pre-alignment method commonly used in photolith...

AI Technical Summary

Problems solved by technology

[0004] The disadvantage of this method is that each measurement system can only measure the position of the two degrees of freedom X and Y, and two sets of measurement systems need to be provided at the same time to measure the rotation Rz of the equipment to be aligned

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