double-sided photolithography

Abstract

The invention discloses a double-sided photolithography method, comprising the following steps: making a first alignment mark (101) on one side or both sides of a substrate (100) to be photoetched; using the first alignment mark (101) ) to align the photolithography plate and the substrate (100) used for the first photolithography, and make graphics and second alignment marks (103) on the substrate (100); using the second alignment marks ( 103) Aligning the photolithography plate and the substrate (100) used for subsequent photolithography, and making subsequent patterns on the substrate (100); the accuracy of the first alignment mark (101) is higher than that of the second Accuracy of registration marks (103). The above method can prevent the pattern from shifting on the substrate.

Description

Technical field [0001] The invention relates to semiconductor manufacturing, in particular to a zero-time exposure method of a double-sided photoetching machine. Background technique [0002] In the semiconductor process, there are some cases where a double-sided processing process is required, for example, when patterns need to be made on both the front and back sides of the silicon wafer, or the size of the chip is larger than 2mm. The double-sided processing technology requires special equipment, a double-sided lithography machine. [0003] The double-sided lithography machine uses proximity or contact exposure, that is, the optical system projects the pattern onto the silicon wafer at a ratio of 1:1. Therefore, the mask used is the same size as the silicon wafer, and the size and position of the pattern on the mask must also be consistent with the actual situation. In this way, the traditional double-sided photolithography process basically uses manual methods to place and al...

AI Technical Summary

Problems solved by technology

However, inaccurate alignment is common in manual placement of masks, including center deviation, that is, the center of the exposure pattern will deviate from the center of the wafer, and the maximum deviation will reach more than ten millimeters; it also includes rotation deviation, that is, the exposure pattern is relative to the wafer. The flat side of the circle will rotate, up to tens of degrees

Although skilled workers can overcome this problem to a large extent, alignment accuracy is still affected by operating proficiency

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