Effect of Hole-Trap Distribution on the Power-Law Time Exponent of NBTI

Author

Ang, D.S. ; Lai, S.C.S. ; Du, G.A. ; Teo, Z.Q. ; Ho, T.J.J. ; Hu, Y.Z.

Author_Institution

Sch. of Electr. & Electron. Eng., Nanyang Technol. Univ., Singapore

Volume

30

Issue

7

fYear

2009

fDate

7/1/2009 12:00:00 AM

Firstpage

751

Lastpage

753

Abstract

This letter presents a phenomenological relationship between the energy distribution of stress-induced hole traps and the power-law time exponent of NBTI. Experimental results show that increased generation of deep-level hole traps (DLHTs), i.e., trap-energy levels are near and/or above the Si conduction-band edge, yields a small exponent (< 0.2). Annealing the DLHTs results in the exponent increasing to ~ 0.3. Measurement on the n-MOSFET (in which the effect of DLHTs is suppressed) shows an exponent of ~0.4-0.5 for interface-state generation. This implies that the relatively small exponent (~0.3) of the p-MOSFET is due to remnant DLHTs which charge-up positively again when subjected to negative gate biasing during measurement. This new insight calls for a reexamination of the notion that as-measured exponents of ~0.14-0.17 are experimental proof of H₂-diffusion-driven interface-state generation.

Keywords

MOSFET; annealing; hole traps; semiconductor device measurement; silicon; thermal stability; DLHT annealing; NBTI; Si; deep-level hole trap distribution effect; hydrogen diffusion-driven interface-state generation; n-MOSFET measurement; negative bias-temperature instability; negative gate biasing; power-law time exponent; silicon conduction band; trap-energy level; Bias-temperature instability (BTI); deep-level hole traps (DLHTs); energy distribution of trapped holes; interface states;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2009.2020445

Filename

4982744