FinFETs with Different Fin Height and EPI Height Setting

摘要

An integrated circuit structure includes a first semiconductor strip, first isolation regions on opposite sides of the first semiconductor strip, and a first epitaxy strip overlapping the first semiconductor strip. A top portion of the first epitaxy strip is over a first top surface of the first isolation regions. The structure further includes a second semiconductor strip, wherein the first and the second semiconductor strips are formed of the same semiconductor material. Second isolation regions are on opposite sides of the second semiconductor strip. A second epitaxy strip overlaps the second semiconductor strip. A top portion of the second epitaxy strip is over a second top surface of the second isolation regions. The first epitaxy strip and the second epitaxy strip are formed of different semiconductor materials. A bottom surface of the first epitaxy strip is lower than a bottom surface of the second epitaxy strip.

主权项

1. A method comprising:
forming a first recess between two portions of a first plurality of shallow trench isolation (STI) regions; performing a first epitaxy to grow a first epitaxy strip in the first recess, wherein the first epitaxy strip is over and contacting a first semiconductor strip portion of a semiconductor substrate; forming a second recess between additional two portions of a second plurality of STI regions; performing a second epitaxy to grow a second epitaxy strip in the second recess, wherein the first epitaxy strip is over and contacting a second semiconductor strip portion of the semiconductor substrate; and recessing the first plurality of STI regions and the second plurality of STI regions to form a second semiconductor fin and a second semiconductor fin, respectively, wherein the first plurality of STI regions is recessed to a first depth smaller than a height of the first epitaxy strip, and the second plurality of STI regions is recessed to a second depth greater than a height of the second epitaxy strip.