Double layer alignment device and double layer aligning method

Abstract

The invention provides a double layer alignment device, which includes a fixing frame, and a first measurement apparatus and a marking plate arranged on the fixing frame, wherein the marking plate is provided with a frame fixing mark, and a moving bench, and a reference mark, a moving bench mark, and a second measurement apparatus that are arranged on the moving bench. The relative positional relation between the reference mark and the moving bench mark is measured through the first measurement apparatus, and the relative positional relation between the reference mark and the frame fixing mark is measured through the second measurement apparatus, so that the final relative positional relation between the moving bench mark and the frame fixing mark is obtained. The moving bench is moved to a set position according to the final relative positional relation. The invention correspondingly provides a double layer aligning method. Only moving bench in the system is a moving part. A static calibration method is used to calibrate a coordinate relation, and the calibration accuracy is not affected by position accuracy of the moving bench, so that the alignment accuracy is improved. Through the design of dual lenses or multiple lenses, the apparatus is flexible in arrangement and improved in alignment efficiency.

Description

technical field [0001] The invention relates to the field of photolithography, in particular to a double-layer alignment device and a double-layer alignment method. Background technique [0002] The alignment system is a core subsystem in semiconductor equipment, and its alignment accuracy often directly determines the overlay accuracy that semiconductor lithography equipment can achieve. Machine vision alignment system has been widely used in semiconductor equipment due to its simple structure, fast speed and high precision. [0003] Compared with the coordinate relationship between the mask plate and the silicon wafer through the objective lens, the lithography machine-like equipment with a relatively simple structure does not have the precise optical equipment such as the objective lens, and a new optical structure and control system must be designed. to achieve double-layer alignment. [0004] Patent US20090251699 (A1) discloses a double-layer alignment scheme. This sc...

AI Technical Summary

Problems solved by technology

However, in this structural scheme, the moving table and the lens are independent moving parts, and the mechanical structure is complex. At the same time, the complexity of motion control will be increased, and the alignment accuracy and reliability will be reduced accordingly.

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