Patent ID: 11880140
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Optics (Instruments)
Classification: CPC G  H | IPC G

Claim 17:
18. A method of performing a photolithography process, comprising:
forming a photosensitive material to have a substantially flat upper surface over a substrate;
focusing electromagnetic radiation over a first depth of focus at a first time, wherein the first depth of focus is centered within the photosensitive material;
focusing the electromagnetic radiation over a second depth of focus at a second time, wherein the second depth of focus is centered within the photosensitive material;
wherein the first depth of focus is directly over the second depth of focus; and
wherein the first depth of focus and the second depth of focus define a collective depth of focus having a dose that is largest at a point that is vertically between a center of the first depth of focus and a center of the second depth of focus.