Patent ID: 11899357
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 14:
15. A mask fabrication process comprising:
providing a substrate coated with a light absorbing layer and a resist layer; and
performing an exposure/development cycle and an etch step to remove portions of the light absorbing layer to define (i) non-absorbing pattern regions of a mask pattern surrounded by a light absorbing border and (ii) a peripheral region outside of the light absorbing border in which the light absorbing layer is removed by the exposure/development cycle;
wherein the peripheral region includes a first peripheral region that extends from an outer perimeter of the light absorbing border to a first edge of the substrate and a second peripheral region that extends from the outer perimeter of the light absorbing border to a second edge of the substrate, the first edge of the substrate and the second edge of the substrate being on opposite sides of the mask pattern; and
wherein the peripheral region does not extend from the outer perimeter of the light absorbing border to a third edge of the substrate, and the peripheral region does not extend from the outer perimeter of the light absorbing border to a fourth edge of the substrate, the third edge of the substrate and the fourth edge of the substrate being on opposite sides of the mask pattern.