Method for minimizing variation in etch rate of semiconductor wafer caused by variation in mask pattern density

摘要

In a method for minimizing a variation in an etch rate of a semiconductor wafer caused by a variation in a mask pattern density, the method includes determining a reference amount of an etch gas for a reference mask pattern density, obtaining an optimized amount of the etch gas for a mask pattern density different from the reference mask pattern density, wherein the optimized amount is obtained by the following equation: $\mathop{\mathrm{image}}$ \frac{\begin{array}{c}(\mathrm{the}\⁢\text{\ }\⁢\mathrm{reference}\⁢\text{\ }\⁢\mathrm{amount}\⁢\text{\ }\⁢\mathrm{for}\⁢\text{\ }\⁢\mathrm{the}\⁢\text{\ }\⁢\mathrm{reference}\⁢\text{\ }\⁢\mathrm{mask}\⁢\text{\ }\⁢\mathrm{pattern}\\ \mathrm{density})\×\left(1-\mathrm{the}\⁢\text{\ }\⁢\mathrm{mask}\⁢\text{\ }\⁢\mathrm{pattern}\⁢\text{\ }\⁢\mathrm{density}\right)\end{array}}{\left(1-\mathrm{the}\⁢\text{\ }\⁢\mathrm{reference}\⁢\text{\ }\⁢\mathrm{mask}\⁢\text{\ }\⁢\mathrm{pattern}\⁢\text{\ }\⁢\mathrm{density}\right)},$$;and the mask pattern density is a value of dividing a mask pattern area by an overall semiconductor wafer area, and applying the optimized amount of the etch gas in an etching process of the semiconductor wafer.