Browsing by Author "Ma, HC"

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Excess low-frequency noise in ultrathin oxide n-MOSFETs arising from valence-band electron tunneling
(2005-09-01)
Wu, JW
;
You, JW
;
Ma, HC
;
Cheng, CC
;
Hsu, CF
Low-frequency flicker noise in analog n-MOSFETs with 15-angstrom gate oxide is investigated. A new noise generation mechanism resulting from valence-band electron tunneling is proposed. In strong inversion conditions, valence-band electron tunneling from Si substrate to polysilicon gate takes place and results in the splitting of electron and hole quasi-Fermi-levels in the channel. The excess low-frequency noise is attributed to electron and hole recombination at interface traps between the two quasi-Fermi-levels. Random telegraph signals due to the capture of channel electrons and holes is characterized in a small area device to support our model.
Investigation of post-NBTI stress recovery in pMOSFETs by direct measurement of single oxide charge de-trapping
(2005)
Chan, CT
;
Ma, HC
;
Tang, CJ
;
Wang, TH
;
電子工程學系及電子研究所
A novel method to study post-NBTI stress recovery in pMOSFETs is demonstrated by direct measurement of single-hole de-trapping behavior. Individual trapped hole emission in NBTI recovery is observed for the first time, which is manifested by the step-like evolution of channel current. By measuring trapped hole emission times and corresponding current jump, the dependence of NBTI recovery on stress hardness, recovery gate voltage and temperature, and gate length is characterized. An analytical model based on thermally-assisted tunneling of trapped oxide charges can successfully reproduce measured recovery characteristics.
Low frequency noise degradation in ultra-thin oxide (I5A) analog n-MOSFETs resulting from valence-band tunneling
(2005)
Wu, JW
;
You, JW
;
Ma, HC
;
Cheng, CC
;
Hsu, C
Abnormal increase of low frequency flicker noise in analog n-MOSFETs with gate oxide in valence band tunneling domain is investigated. In 15 angstrom oxide devices, valence-band electron tunneling from Si substrate to poly-gate occurs at a positive gate voltage and results in the splitting of electron and hole quasi Fermi-levels in the channel. The excess low frequency noise is attributed to electron and hole recombination at interface traps between the two quasi Fermilevels. The trap capture and emission times in valence band tunneling domain are extracted from random telegraph signal. The dependence of measured trap times on gate voltage is consistent with our proposed model.
Single-electron emission of traps in HfSiON as high-k gate dielectric for MOSFETs
(2005)
Chan, CT
;
Tang, CJ
;
Kuo, CH
;
Ma, HC
;
Tsai, CW
A novel method for characterizing MOSFETs with HfSiON high-k gate dielectric is demonstrated for the first time by direct measurement of single-electron de-trapping. Individual high-k trapped electron emission is recorded, which is manifested by the step-like evolution of channel current. The physical path of electron de-trapping can be identified from the emission time of such single-electron de-trapping. The dependence of charge emission time on gate voltage and temperature is measured. An analytical model based on thermally assisted tunneling can predict the emission time behavior, trap activation energy, trap density, and total available traps in high-k gate dielectric.
Valence-band tunneling induced low frequency noise in ultrathin oxide (15 angstrom) n-type metal-oxide-semiconductor field effect transistors
(2004-11-22)
Wu, JW
;
You, JW
;
Ma, HC
;
Cheng, CC
;
Chang, CS
Low frequency flicker noise in n-type metal-oxide-semiconductor field effect transistors (n-MOSFETs) with 15 Angstrom gate oxide is investigated. A noise generation mechanism resulting from valence band tunneling is proposed. In strong inversion condition, valence-band electron tunneling takes place and results in the splitting of electron and hole quasi-Fermi levels in the channel. The excess low frequency noise is attributed to electron and hole recombination at interface traps between the two quasi-Fermi levels. Random telegraph signal in a small area device is characterized to support our model. (C) 2004 American Institute of Physics.