Fabrication of low threshold voltage and inversion oxide thickness scaling for a high-k metal gate p-type MOSFET

Patent metadata

Field	Value
Publication number	US-9105745-B2
Application number	US-201213630235-A
Country	US
Kind code	B2
Filing date	Sep 28, 2012
Priority date	Jun 18, 2009
Publication date	Aug 11, 2015
Grant date	Aug 11, 2015

Abstract

A method of forming a semiconductor structure. The semiconductor structure has a semiconductor substrate and an nFET and a pFET disposed upon the substrate. The pFET has a semiconductor SiGe channel region formed upon or within a surface of the semiconductor substrate and a gate dielectric having an oxide layer overlying the channel region and a high-k dielectric layer overlying the oxide layer. A gate electrode overlies the gate dielectric and has a lower metal layer abutting the high-k layer, a scavenging metal layer abutting the lower metal layer, and an upper metal layer abutting the scavenging metal layer. The metal layer scavenges oxygen from the substrate (nFET) and SiGe (pFET) interface with the oxide layer resulting in an effective reduction in T inv and V t of the pFET, while scaling Tinv and maintaining Vt for the nFET, resulting in the V t of the pFET becoming closer to the V t of a similarly constructed nFET with scaled T inv values.

First claim

What is claimed is:

1. A method of forming a semiconductor structure comprising:
providing a semiconductor substrate comprising a semiconductor material;
forming a p-type field effect transistor (pFET) disposed upon said semiconductor substrate and comprising a semiconductor channel region comprised of SiGe formed upon or within a surface of said semiconductor substrate;
forming a gate dielectric comprising an oxide layer overlying said semiconductor channel region comprised o…

Assignees

• IBM

Inventors

• Ando Takashi
• Choi Changhwan
• Frank Martin M
• Kwon Unoh
• Narayanan Vijay

Classifications

• H10D84/0167 Primary

  Electricity · mapped topic

• H10D84/038

  Electricity · mapped topic

• H10D64/691

  Electricity · mapped topic

• H10D64/667

  Electricity · mapped topic

• H10D64/514

  Electricity · mapped topic