MOSFET performance degradation due to hot carriers

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6831748

Choi, J Y

Hot-carrier-induced degradation of short-channel MOSFET's is investigated. It is shown that both charge trapping and interface-state generation take place. The relative importance of the two mechanisms depends on the bias condition and the electron-trap density in the oxide. For oxides fabricated with the state-of-art technology and for the worst-case bias condition, hot-electron trapping contributes less than 10% to the device degradation and interface-state generation is the dominant mechanism of DC stress-device degradation. Under pulsed stressing condition, however, hot-carrier trapping rate is increased due to the neutral oxide traps generated by the hot holes. While the substrate current is a useful tool for extrapolating lifetime of hot-carrier-induced MOSFET degradation from accelerated stressing data, the substrate current can vary significantly during a constant-voltage stress test. The device degradation was studied, using a constant-field method. The critical electron energy for device degradation is found to be 3 to 6 eV, depending on the oxide electric field. These values are 50% higher than those reported elsewhere. The effects of gate- and drain-voltage waveforms on the hot-carrier-induced MOSFET degradation are studied. Drain-voltage transients have little effect on the degradation rate. Only the falling edge of the gate pulse in the presence of a high-drain voltage enhances the degradation rate.

• Research Organization: California Univ., Berkeley (USA)
• OSTI ID: 6831748
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
CHARGE CARRIERS
CURRENTS
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
FIELD EFFECT TRANSISTORS
MOS TRANSISTORS
MOSFET
PERFORMANCE
PULSES
SEMICONDUCTOR DEVICES
TRANSISTORS
TRAPPING