Method for forming N-shaped bottom stress liner
AssigneeGlobalfoundries Singapore Pte. Ltd.
InventorsXiaodong Yang, Yanxiang Liu, Vara Govindeswara Reddy Vakada, Jinping Liu, Min Dai
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Abstract
Semiconductor devices with n-shaped bottom stress liners are formed. Embodiments include forming a protuberance on a substrate, conformally forming a sacrificial material layer over the protuberance, forming a gate stack above the sacrificial material layer on a silicon layer, removing the sacrificial material layer to form a tunnel, and forming a stress liner in the tunnel conforming to the shape of the protuberance. Embodiments further include forming a silicon layer over the sacrificial material layer and lining the tunnel with a passivation layer prior to forming the stress liner.
Claims12
A method comprising:
- forming a protuberance on a substrate;
- conformally forming a sacrificial material layer over the protuberance;
- forming a gate stack above the sacrificial material layer on a silicon layer;
- removing the sacrificial material layer, forming a tunnel;
- and
- forming a stress liner in the tunnel conforming to the shape of the protuberance.
A method comprising:
- etching a silicon substrate to form a protuberance on the silicon substrate;
- epitaxially growing a silicon germanium (SiGe) layer over the protuberance;
- forming a silicon layer above the SiGe layer, a surface of the silicon layer contiguous with the SiGe layer conforming to the shape of the protuberance;
- forming source/drain regions above or embedded within the silicon layer;
- forming a gate stack above the protuberance on the silicon layer;
- removing the SiGe layer, forming a tunnel;
- and
- forming a stress liner in the tunnel conforming to the shape of the protuberance.
Dependencies are inferred from the claim text.