Method of manufacturing a fin-like field effect transistor (FinFET) device

摘要

A FinFET device and method for fabricating a FinFET device is disclosed. An exemplary FinFET device includes a semiconductor substrate; a fin structure disposed over the semiconductor substrate; and a gate structure disposed over a portion of the fin structure. The gate structure traverses the fin structure and separates a source region and a drain region of the fin structure, the source and drain region defining a channel therebetween. The source and drain region of the fin structure include a strained source and drain feature. The strained source feature and the strained drain feature each include: a first portion having a first width and a first depth; and a second portion disposed below the first portion, the second portion having a second width and a second depth. The first width is greater than the second width, and the first depth is less than the second depth.

主权项

1. A method comprising:
forming a fin structure over a substrate; forming a first gate structure over a first portion of the fin structure and a second gate structure over a second portion of the fin structure, wherein a third portion of the fin structure interposes the first and second portions; forming seal spacers on sidewalls of each of the first gate structure and the second gate structure; forming dummy spacers adjacent to each of the seal spacers; forming a trench having a first U-shaped profile in the fin structure, wherein the trench has a first sidewall collinear with a first dummy spacer on the first gate structure and a second opposing sidewall collinear with a second dummy spacer on the second gate structure, and a first bottom curvilinear surface extending to a first depth, wherein the first and second sidewalls and the first bottom curvilinear surface are defined by the fin structure; thereafter, removing the dummy spacers; modifying the trench having the first U-shaped profile in the fin structure, such that the trench has a second profile at an upper region of the trench and the first U-shaped profile at a lower region of the trench, wherein the upper region of the trench has a third sidewall collinear with a first seal spacer on the first gate structure and a fourth opposing sidewall collinear with a second seal spacer on the second gate structure, and wherein the modifying the trench includes increasing a depth of the trench to a second depth greater than the first depth, wherein increasing the depth includes etching the first bottom curvilinear surface of the fin structure to form a second curvilinear surface at the second depth, the second bottom curvilinear surface defined by the fin structure, and wherein the second depth to first depth has a ratio of approximately 1 to 2/3; and epitaxially (epi) growing a semiconductor material in the trench after the modifying.