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.