Patent ID: 11923360
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 3:
4. A method for forming a semiconductor device, comprising:
forming a pair of semiconductor fins extending upwardly from a substrate;
forming a dummy fin structure extending upwardly above the substrate and laterally between the pair of semiconductor fins;
forming a shallow trench isolation structure laterally surrounding lower portions of the pair of semiconductor fins and the dummy fin structure;
forming a gate structure extending across the pair of semiconductor fins and the dummy fin structure;
forming a plurality of source/drain structures above the pair of semiconductor fins and on either side of the gate structure;
forming a crystalline hard mask layer extending upwardly from the dummy fin structure and having a U-shaped cross section; and
forming an amorphous hard mask layer in the crystalline hard mask layer, wherein the amorphous hard mask layer having a U-shaped cross section conformal to the U-shaped cross section of the crystalline hard mask layer.