Emission probability of hot electrons for highly doped silicon-on-sapphire IGFET

Experimental measurements of the probability of emission of hot electrons into the oxide of silicon-on-sapphire (SOS) MOS devices are presented for high doping levels. The experimental method is derived from the optically induced hot electron experiment as proposed by Ning. The dependence of the emission probability on device parameters and applied voltage is analyzed emphasizing the lucky electron model and the sensitivity of the model to device characterization. We found that the expression
P = P'_{0} \exp (-d/\lambda_{eff})
describes the experimental data very well, taking
P'_{0} = 0.5
and
lambda_{eff} = 95
Å. It shows that hot carrier properties of SOS are the same as those of bulk silicon. The results also show that hot electron related instabilities can arise for bias voltages lower than 2 V when the doping level reaches 1 × 10
¹⁸
At/cm
³
.