Patent ID: 11914288
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A method comprising:
forming a photoresist layer over a wafer;
exposing the photoresist layer to a pattern of radiation using a photomask, wherein the photomask comprises:
a substrate having a recessed region recessed from a first surface of the substrate and having a first width;
at least one opaque main feature protruding from the first surface of the substrate and having a second width greater than the first width of the recessed region of the substrate, wherein a height of the at least one opaque main feature is greater than a depth of the recess region of the substrate; and
an opaque filling in the recessed region, wherein a top surface of the opaque filling is substantially coplanar with a top surface of the at least one opaque main feature; and

developing the photoresist layer after exposing the photoresist layer to the pattern of radiation.