Increased hot-carrier effects using SiGe layers in vertical surrounding-gate MOSFETs

Author

Date, Celisa K. ; Plummer, James D.

Author_Institution

Paul Allen Center for Integrated Syst., Stanford Univ., CA, USA

Volume

48

Issue

12

fYear

2001

fDate

12/1/2001 12:00:00 AM

Firstpage

2690

Lastpage

2694

Abstract

The use of silicon germanium (SiGe) heterostructures in vertical surrounding gate MOSFETs provides an additional means for tailoring current-voltage (I-V) characteristics by controlling physical effects inside the device. Incorporation of an SiGe layer in the vertical MOSFET drain can modify hot-carrier characteristics via material dependent impact ionization coefficients. MOSFETs with ramped SiGe drain layers showed increased drain current in the soft breakdown regime, due to increased impact ionization as verified by substrate current measurement, with up to 1.5 V decreases in breakdown voltage. Comparison of simulation to experiment displayed the difficulties of accurately predicting device parameters, but demonstrated the usefulness of simulation to qualitatively predict device behavior without costly expenditures of time, material, and equipment

Keywords

Ge-Si alloys; MOSFET; avalanche breakdown; hot carriers; impact ionisation; semiconductor device breakdown; semiconductor device models; I-V characteristics; SiGe; SiGe heterostructures; avalanche breakdown; breakdown voltage; current-voltage characteristics; drain engineering; hot-carrier characteristics; material dependent impact ionization coefficients; ramped SiGe drain layers; simulation; soft breakdown regime; vertical MOSFET drain; vertical surrounding gate MOSFETs; Charge carrier processes; Electrons; Germanium silicon alloys; Hot carrier effects; Hot carriers; Impact ionization; MOSFETs; Predictive models; Silicon germanium; Voltage;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/16.974691

Filename

974691