Hole-trapping/hydrogen transport (HT) sup 2 model for interface-trap buildup in MOS devices

Conference · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6763446

Shaneyfelt, M R; Schwank, J R; Fleetwood, D M; Winokur, P S

The electric field dependence of radiation-induced interface-trap formation has been reported to be different for metal-gate capacitors and polysilicon-gate capacitors and transistors. For metal-gate capacitors, interface-trap formation steadily increases with increasing positive field. On the other hand, for polysilicon-gate capacitors and transistors, interface-trap buildup peaks near fields of 1 MV/cm to 2 MV/cm and decreases with an approximate E{sup {minus}1/2} dependence at higher fields. The previously reported field dependence for interface-trap generation for Al-gate capacitors is consistent at all fields with McLean's physical explanation of the two-stage process, which depends on hydrogen ion (H {sup +}) release in the bulk of the oxide as radiation-induced holes transport to either interface via polaron hopping. Above 1 MV/cm, the field dependence of interface-trap buildup for polysilicon-gate devices is inconsistent with this model. Instead, it is similar to the field dependence for hole-trapping in SiO{sub 2}, suggesting that hole trapping may play a key role in interface-trap generation in Si-gate devices. However, recent studies of the time-dependence of interface-trap buildup have known that hole trapping cannot be the rate-limiting step in interface-trap buildup in polysilicon gate devices. Consistent with McLean's physical explanation of the two-stage process, the rate-limiting step in interface-trap formation appears to be H{sup +} transport to the Si/SiO{sub 2} interface. We will show that the electric field dependence of radiation-induced oxide- and interface-trap charge buildup for both polysilicon and metal-gate transistors follows an approximate E{sup {minus}1/2} field dependence over a wide range of electric fields when electron-hole recombination effects are included. Based on these results a hole trapping/hydrogen transport (HT){sup 2} model for interface-trap buildup is proposed.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• Sponsoring Organization: DOE/DP
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6763446
• Report Number(s): SAND-90-2291C; CONF-901235-2; ON: DE91000020
• Resource Relation: Conference: 21. IEEE semiconductor interface specialists conference, San Diego, CA (USA), 6-8 Dec 1990
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
MOS TRANSISTORS
HOLE MOBILITY
ELECTRIC FIELDS
HOLES
HYDROGEN IONS 1 PLUS
INTERFACES
RECOMBINATION
TRAPPED PROTONS
TRAPPING
BARYONS
CATIONS
CHARGED PARTICLES
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HYDROGEN IONS
IONS
MOBILITY
NUCLEONS
PROTONS
SEMICONDUCTOR DEVICES
TRANSISTORS
426000* - Engineering- Components
Electron Devices & Circuits- (1990-)
656002 - Condensed Matter Physics- General Techniques in Condensed Matter- (1987-)