Interface defect formation in MOSFETs by atomic hydrogen exposure

Conference · Thu Dec 01 04:00:00 EST 1994 · IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States)

OSTI ID:6763568

Stahlbush, R E ^[1]; Cartier, E ^[2]

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1. Naval Research Lab., Washington, DC (United States)
2. IBM T.J. Watson Research Center, Yorktown Heights, NY (United States)

The formation of interface defects that occurs when atomic hydrogen, H[degree], is introduced into the gate oxide of MOSFETs at room temperature has been studied. MOSFETs with the edges of the gate oxide at the source and drain exposed to the ambient were placed downstream of a hydrogen plasma. Baffles prevent UV light from the plasma from reaching the device. The effective channel lengths ranged from 0.9 to 5 [mu]m. For comparison, bare thermal oxides were exposed at the same time. The interface state density in the MOSFETs was measured by charge pumping and in the bare oxide by high-low capacitance-voltage measured with a Hg probe. The authors observe that the induced damage has the same energy distribution of interface traps in both types of samples. This distribution is very similar to that produced by irradiation or hot electron stressing. It is characterized by a broad peak at 0.7 eV above the valence band. A charge pumping analysis has been developed to measure interface states as a function of position above the MOSFET source and drain regions. The degradation decreases exponentially from the point of H[degree] entry at the gate edges near the source and drain. This demonstrates that the hydrogen enters the gate oxide of the MOSFET at the channel edges. Furthermore, the decay length is constant within the experimental uncertainty over three orders of magnitude of H[degree] dose and two orders of magnitude of interface trap density.

• OSTI ID: 6763568
• Report Number(s): CONF-940726--
• Conference Information: Journal Name: IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States) Journal Volume: 41:6Pt1
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426000* -- Engineering-- Components
Electron Devices & Circuits-- (1990-)
AMBIENT TEMPERATURE
COMPARATIVE EVALUATIONS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTROMAGNETIC RADIATION
EVALUATION
FIELD EFFECT TRANSISTORS
INTERFACES
MOS TRANSISTORS
MOSFET
RADIATIONS
SEMICONDUCTOR DEVICES
TRANSISTORS
ULTRAVIOLET RADIATION