Optimization of chrome dry etch in Tetra II using asymmetrically loaded patterns

Asymmetrically loaded patterns have been used to develop and optimize the chrome etch process on the TetraO II, the next -generation tool offered by Etec Systems. These asymmetrically loaded patterns offer unique challenges to the dry etch process by concentrating much of the chrome load in one section of the mask (usually one quadrant) while leaving the rest of the mask uniformly loaded. Numerical analysis of both the final chrome and the point-by-point etch contribution has been implemented to allow accurate interpretation of etch results.