Non-planar transistors with replacement fins and methods of forming the same

摘要

A method includes forming a first semiconductor fin, and oxidizing surface portions of the first semiconductor fin to form a first oxide layer. The first oxide layer includes a top portion overlapping the first semiconductor fin and sidewall portions on sidewalls of the first semiconductor fin. The top portion of the first oxide layer is then removed, wherein the sidewall portions of the first oxide layer remains after the removing. The top portion of the first semiconductor fin is removed to form a recess between the sidewall portions of the first oxide layer. An epitaxy is performed to grow a semiconductor region in the recess.

主权项

1. A method comprising:
forming a first, a second, and a third semiconductor fin; simultaneously oxidizing sidewall portions of the first, the second, and the third semiconductor fins to form a first, a second, and a third oxide layer, respectively; replacing a top portion of the first semiconductor fin with a first replacement fin; replacing a top portion of the second semiconductor fin with a second replacement fin; removing the first and the second oxide layers without removing the third oxide layer; forming a first gate dielectric on a top surface and sidewalls of the first replacement fin; forming a second gate dielectric on a top surface and sidewalls of the second replacement fin; and forming a third gate dielectric on a top surface and sidewalls of the third oxide layer.