Photoetching process method

Abstract

The invention discloses a photoetching process method, which comprises the following steps: providing a product wafer, and measuring a first surface height distribution in an exposure plane before photoresist applying; applying photoresist, and measuring a second surface height distribution in the exposure plane; dividing the exposure plane into n exposure subareas and calculating a third thickness value of the photoresist in each exposure subarea; providing n test wafers and coating the n test wafers with photoresist with a third thickness; exposing the test wafers; measuring the line width of each test exposure pattern to obtain a corresponding reference pattern line width and calculating the exposure pattern line width difference of each exposure subarea; converting each exposure pattern line width difference into a design pattern line width difference on a product mask; manufacturing a product mask, and adding the design pattern line width difference to perform line width correction; and coating the product wafer with photoresist, and carrying out exposing and developing. According to the invention, exposure pattern line width difference caused by uneven surface morphology in the wafer exposure plane can be reduced or eliminated, and the line width uniformity of the product can be improved.

Description

technical field

[0001] The invention relates to a semiconductor integrated circuit manufacturing method, in particular to a photolithography process method. Background technique

[0002] Photolithography is the process of transferring the pattern prepared in advance on the mask (Mask) to the substrate by using the principle of photochemical reaction. In the complete process of integrated circuit manufacturing, multi-layer photolithography is required, and the patterns and substrates of each layer of photolithography are different. The appearance is uneven (surfacetopography). When the photoresist is coated on the substrate of the wafer, it will be unevenly distributed according to the difference in the surface topography of the wafer. Due to the existence of the standing wave effect (standing wave) and the bulk effect (bulk effect), the graphics with the same line width are designed in the The exposed line width on the photoresist with different thicknesses will be differe...

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