Ultra thin body fully-depleted SOI MOSFETs

US7459752B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Bruce B. Doris · Brewster, US
• Meikei Ieong · Wappingers Falls, US
• Zhibin Ren · Hopewell Junction, US
• Paul M. Solomon · Yorktown Heights, US
• Min Yang · Yorktown Heights, US

Key dates

• Filing date: Jun 23, 2006
• Grant date: Dec 2, 2008
• Expiry date: Oct 28, 2026

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/017

Abstract

Ultra thin body fully-depleted silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect-transistors (MOSFETs) in which the SOI thickness changes with gate-length variations thereby minimizing the threshold voltage variations that are typically caused by SOI thickness and gate-length variations are provided. Such a SOI MOSFET may include a SOI substrate having a SOI layer in which a first portion thereof has a thickness of less than 20 nm; a gate including a gate dielectric and a gate electrode located atop the first portion of the SOI layer having the thickness, the gate electrode having an upper surface and a bottom surface that have the same length or the bottom surface has a length that is greater than the upper surface; and source and drain diffusion regions located in a second portion of the SOI layer that is adjacent to the first portion, and the second portion of the SOI layer is thicker than the first portion.