Patent ID: 11894238
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. A method comprising:
forming a first material layer over a substrate;
forming a second material layer directly on the first material layer, the second material layer being formed of a different material than the first material layer;
forming a patterned third material layer directly on the second material layer, the patterned third material layer defining a first trench exposing a first portion of the second material layer;
forming a first spacer layer directly on the second material layer within the first trench;
forming a second trench in the patterned third material layer to expose a second portion of the second material layer;
removing the first portion of the second material layer to extend the first trench into the second material layer and removing the second portion of the second material layer to extend the second trench into the first material layer thereby forming a patterned second material layer;
removing the patterned third material layer and the first spacer layer;
forming a fourth material layer over the patterned second material layer;
forming a third trench extending through the fourth material layer to thereby form a patterned fourth material layer, wherein the third trench at least partially overlaps the extended first trench;
removing a third portion of the patterned second material layer through the third trench; and
after removing the third portion of the patterned second material layer through the third trench, patterning the first material layer by using the patterned second material layer as a first mask.