| US 7,575,975 B2 | ||
| Method for forming a planar and vertical semiconductor structure having a strained semiconductor layer | ||
| Voon-Yew Thean, Austin, Tex. (US); Jian Chen, Austin, Tex. (US); Bich-Yen Nguyen, Austin, Tex. (US); Mariam G. Sadaka, Austin, Tex. (US); and Da Zhang, Austin, Tex. (US) | ||
| Assigned to Freescale Semiconductor, Inc., Austin, Tex. (US) | ||
| Filed on Oct. 31, 2005, as Appl. No. 11/263,120. | ||
| Prior Publication US 2007/0099353 A1, May 03, 2007 | ||
| Int. Cl. H01L 21/00 (2006.01); H01L 21/84 (2006.01); H01L 21/8234 (2006.01); H01L 27/088 (2006.01) | ||
| U.S. Cl. 438—275 [438/154; 438/938; 257/331; 257/365; 257/369; 257/347; 257/204; 257/285; 257/351; 257/401] | 17 Claims |
| 1. A method for forming a semiconductor structure, the method comprising:
providing a substrate, said substrate comprising a strained semiconductor layer overlying an insulating layer;
providing a first device region for forming a first plurality of devices having a first conductivity type;
providing a second device region for forming a second plurality of devices having a second conductivity type, wherein the
second conductivity type is different than the first conductivity type;
wherein the first plurality of devices comprise planar devices and the second plurality of devices comprise vertical devices;
thickening the strained semiconductor layer in the second device region to form a thickened strained semiconductor layer so
that the thickened strained semiconductor layer in the second device region has less strain than the strained semiconductor
layer in the first device region;
wherein said step of thickening comprises: epitaxially growing a same semiconductor material as the strained semiconductor
layer directly on the strained semiconductor layer to form the thickened semiconductor layer;
wherein said step of thickening comprises: forming a masking layer overlying the first device region, and performing selective
epitaxial growth to thicken the strained semiconductor layer in the second device region and not in the first device region;
wherein a thickness of a portion of the strained semiconductor layer which is epitaxially grown is thicker than a thickness
of the masking layer; and
forming the first plurality of devices in the first device region and the second plurality of devices in the second device
region, wherein source/drain regions of the first plurality of devices are formed within the strained semiconductor layer
and source/drain regions of the second plurality of devices are formed within the thickened strained semiconductor layer,
wherein said step of forming the second plurality of devices in the second device region comprises:
after said step of thickening the strained semiconductor layer in the second device region, removing portions of the thickened
strained semiconductor layer to expose the insulating layer; and
after said step of removing the portions of the thickened strained semiconductor layer, forming a gate dielectric layer adjacent
sidewalls of the thickened strained semiconductor layer.
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