发明名称 |
Fin structures and multi-Vt scheme based on tapered fin and method to form |
摘要 |
A method of forming a FinFET fin with low-doped and a highly-doped active portions and/or a FinFET fin having tapered sidewalls for Vt tuning and multi-Vt schemes and the resulting device are provided. Embodiments include forming an Si fin, the Si fin having a top active portion and a bottom active portion; forming a hard mask on a top surface of the Si fin; forming an oxide layer on opposite sides of the Si fin; implanting a dopant into the Si fin; recessing the oxide layer to reveal the active top portion of the Si fin; etching the top active portion of the Si fin to form vertical sidewalls; forming a nitride spacer covering each vertical sidewall; recessing the recessed oxide layer to reveal the active bottom portion of the Si fin; and tapering the active bottom portion of the Si fin. |
申请公布号 |
US9583625(B2) |
申请公布日期 |
2017.02.28 |
申请号 |
US201414523548 |
申请日期 |
2014.10.24 |
申请人 |
GLOBALFOUNDRIES INC. |
发明人 |
Wu Xusheng;Chi Min-hwa;Banghart Edmund Kenneth |
分类号 |
H01L29/78;H01L29/66;H01L29/06;H01L29/10 |
主分类号 |
H01L29/78 |
代理机构 |
Ditthavong & Steiner, P.C. |
代理人 |
Ditthavong & Steiner, P.C. |
主权项 |
1. A method comprising:
forming a silicon (Si) fin, the Si fin having an active top portion and an active bottom portion; forming a hard mask on a top surface of the Si fin; forming an oxide layer on opposite sides of the Si fin; implanting a dopant into the Si fin; recessing the oxide layer to reveal the active top portion of the Si fin; etching the active top portion of the Si fin to form vertical sidewalls; forming a nitride spacer covering each vertical sidewall, the nitrate spacer having a top and a bottom, wherein the top contacts the hard mask, and the bottom is closer than the top to the recessed oxide layer; recessing the recessed oxide layer to reveal the active bottom portion of the Si fin; and tapering the active bottom portion of the Si fin, such that the opposite sides of the Si fin extend in a straight line from a wider portion of the Si fin at the recessed oxide layer, which has been recessed, to a narrower portion of the Si fin where the Si fin contacts the bottom of the nitride spacer. |
地址 |
Grand Cayman KY |