Roughness-enhanced reliability of MOS tunneling diodes

Both electrical and optical reliabilities of PMOS and NMOS tunneling diodes are enhanced by oxide roughness, prepared by very high vacuum prebake technology. For the rough PMOS devices, as compared to the flat PMOS devices, the Weibull plot of T _BD shows 2.5-fold enhancement at 63% failure rate, while both the D ₂ and H ₂-treated flat PMOS devices show similar inferior reliability. For the rough NMOS devices, as compared to the flat NMOS devices, the Weibull plot of T _BD shows 4.9-fold enhancement at 63% failure rate. The time evolutions of the light emission from the rough PMOS and NMOS diodes degrade much less than those of the flat PMOS and NMOS diodes. The momentum reduction perpendicular to the Si/SiO ₂ interface by roughness scattering could possibly make it difficult to form defects in the bulk oxide and at the Si/SiO ₂ interface by the impact of the energetic electrons and holes.