New observations on the physical mechanism of Vth-variation in nanoscale CMOS devices after long term stress

Author

Hsieh, E.R. ; Chung, Steve S. ; Tsai, C.H. ; Huang, R.M. ; Tsai, C.T. ; Liang, C.W.

Author_Institution

Dept. of Electron. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan

fYear

2011

fDate

10-14 April 2011

Abstract

A new effect, called random trap fluctuation(RTF), is proposed to study the impact of hot carrier stress on the device variability. It was found that not only the popular random dopant fluctuation (RDF), but also the traps, caused by the HC stress or FN-stress, induce the V_th variation. After the FN stress, it was found that V_th variation is worse in pMOSFETs due to stress-induced interface traps. While, under the HC stress, different V_th variations were found for nMOSFETs and pMOSFETs. The V_th variation is enhanced in pMOSFETs due to RTF and reduced in nMOSFET as a result of the Trap Blocking Effect (TBE). RTF in pMOSFET might be the dominant factor of CMOS reliability for future generations.

Keywords

CMOS integrated circuits; MOSFET; hole traps; hot carriers; random processes; semiconductor device reliability; CMOS reliability; FN-stress; HC stress; RDF; RTF; TBE; device variability; dominant factor; hot carrier stress; nMOSFET; nanoscale CMOS devices; pMOSFET; physical mechanism; popular random dopant fluctuation; random trap fluctuation; stress-induced interface traps; trap blocking effect; CMOS integrated circuits; Fluctuations; Logic gates; MOSFETs; Stress; Very large scale integration; hot carrier effect; random dopant fluctuation; random trap fluctuation;

fLanguage

English

Publisher

ieee

Conference_Titel

Reliability Physics Symposium (IRPS), 2011 IEEE International

Conference_Location

Monterey, CA

ISSN

1541-7026

Print_ISBN

978-1-4244-9113-1

Electronic_ISBN

1541-7026

Type

conf

DOI

10.1109/IRPS.2011.5784610

Filename

5784610