Title :
Hole transport in UTB MOSFETs in strained-Si directly on insulator with strained-Si thickness less than 5 nm
Author :
Aberg, Ingvar ; HOyt, Judy L.
Author_Institution :
MIT Microsystems Technol. Labs., Cambridge, MA, USA
Abstract :
Hole transport is studied in ultrathin body (UTB) MOSFETs in strained-Si directly on insulator (SSDOI) with a Si thickness down to 1.4 nm. In these Ge-free SSDOI substrates, the Si is strained in biaxial tension with strain levels equivalent to strained-Si on relaxed SiGe, with Ge contents of 30 and 40% Ge. The hole mobility in SSDOI decreases slowly for Si thicknesses above 4 nm, but drops rapidly below that thickness. Relative to silicon-on-insulator control devices of equal thickness, SSDOI displays significant hole mobility enhancement for Si film thicknesses above 3.5 nm. Peak hole mobility is improved by 25% for 40% SSDOI relative to 30% SSDOI fabricated by the same method, demonstrating the benefits of strain engineering for 3.1-nm-thick UTB MOSFETs.
Keywords :
Ge-Si alloys; MOSFET; hole mobility; nanotechnology; silicon-on-insulator; 1.4 nm; 3.1 nm; SSDOI substrate; SiGe; UTB MOSFET; hole transport; peak hole mobility; relaxed SiGe; silicon-on-insulator control device; strain engineering; strained-Si directly on insulator; strained-Si thickness; ultrathin body MOSFET; Capacitive sensors; Displays; Germanium silicon alloys; Insulation; MOSFETs; Semiconductor films; Silicon germanium; Silicon on insulator technology; Substrates; Thickness control; MOSFETs; Mobility; silicon-on-insulator (SOI); strained-silicon (Si); strained-silicon directly on insulator (SSDOI); ultrathin body (UTB);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2005.853648