Patent ID: 11959864
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 8:
9. A photolithography method, comprising:
receiving a wafer with a target layer over the wafer;
coating the target layer with a bottom layer using a dispensing nozzle at a first distance from the target layer;
vertically moving the dispensing nozzle such that the dispensing nozzle is at a second distance from the target layer, wherein the second distance is different from the first distance;
coating the bottom layer with a middle layer using the dispensing nozzle at the second distance from the target layer;
vertically moving the dispensing nozzle such that the dispensing nozzle is at a third distance from the target layer, wherein the third distance is different from the first and second distances, and wherein the first, second, and third distances are sensed by a distance sensor;
coating the middle layer with a top layer using the dispensing nozzle at the third distance from the target layer;
curing the bottom layer, the middle layer, and the top layer to form a tri-layer photoresist;
patterning the tri-layer photoresist; and
patterning the target layer using the patterned tri-layer photoresist as a mask.