25-nm Gate Length nMOSFET With Steep Channel Profiles Utilizing Carbon-Doped Silicon Layers (A P-Type Dopant Confinement Layer)

Author

Hokazono, Akira ; Itokawa, Hiroshi ; Kusunoki, Naoki ; Mizushima, Ichiro ; Inaba, Satoshi ; Kawanaka, Shigeru ; Toyoshima, Yoshiaki

Author_Institution

Semicond. Co., Center for Semicond. R&D, Toshiba Corp., Yokohama, Japan

Volume

58

Issue

5

fYear

2011

fDate

5/1/2011 12:00:00 AM

Firstpage

1302

Lastpage

1310

Abstract

Steep channel profiles of scaled transistors are a promising approach for advancing transistor generation in bulk complementary metal-oxide-semiconductor (MOS). In this paper, a carbon-doped Si (Si:C) layer under an undoped Si layer is proposed to form steep p-type channel profiles in n-channel MOS field-effect transistors (nMOSFETs) due to extremely low diffusivity of boron and indium in Si:C layers. This structure with low channel impurity improves mobility and suppresses threshold voltage (V_TH) variation. Both items are essential for aggressively scaled MOSFETs with a gate length less than 25 nm. We demonstrated well-controlled, high-performance, and low V_TH variability nMOSFETs with a Si:C-Si epitaxial channel structure.

Keywords

MOSFET; epitaxial layers; silicon; P-type dopant confinement layer; Si; boron diffusivity; carbon-doped silicon layers; epitaxial channel structure; gate length nMOSFET; metal-oxide-semiconductor; n-channel MOS field-effect transistors; size 25 nm; steep channel profiles; threshold voltage suppression; Carbon; Doping; Epitaxial growth; Logic gates; MOS devices; Silicon; Transistors; Carbon-doped Si (Si:C); epitaxial layers (epi-layer); mobility; random dopant fluctuation; steep channel profile;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2011.2112770

Filename

5742992