Patent ID: 11889674
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 7:
8. A method, comprising:
providing a substrate comprising a first semiconductor layer, a second semiconductor layer over the first semiconductor layer, and a third semiconductor layer disposed over the second semiconductor layer;
forming a first fin structure over a first region of the substrate and a second fin structure over a second region of the substrate, the first fin structure comprising a first lower portion formed of the first semiconductor layer, a first middle portion formed of the second semiconductor layer, and a first top portion formed of the third semiconductor layer, the second fin structure comprising a second lower portion formed of the first semiconductor layer, a second middle portion formed of the second semiconductor layer, and a second top portion formed of the third semiconductor layer;
forming a patterned mask layer to cover an entirety of the second fin structure and a first portion of the first fin structure while a second portion of the first fin structure is exposed; and
after the forming of the patterned mask layer, oxidizing the second portion of the first fin structure to convert the first middle portion to a semiconductor oxide.