Drain-avalanche and hole-trapping induced gate leakage in thin-oxide MOS devices

Leakage current components due to band-to-band tunneling and avalanche breakdown in thin-oxide (90-160 AA) gated-diode structures are discussed. Experimental results show that while the band-to-band tunneling current is not sensitive to channel doping concentration, the avalanche current is sensitive to channel doping concentration in the range of 10/sup 16/ to 10/sup 17/ cm/sup -3/. For oxides thicker than 110 AA, the gate current is found to be dominated by hot-hole injection and for oxides thinner than 110 AA the gate current is dominated by Fowler-Nordheim electron tunneling. After hot-hole injection, the gate oxide exhibits significant low-level leakage, which is explained by the barrier-lowering effect caused by the trapped holes in the oxide.<>