一种具有超强电荷积累效应的高优值超结SOI LDMOS

A novel silicon-on-insulator(SOI) super-junction(SJ) LDMOS with an ultra-strong charge accumulation effect is proposed. It has two key features: an assisted-accumulation trench-type extending gate(TEG) with a high-k(HK) dielectric and a step-dopedN pillar(TEG-SD SJ LDMOS). In the on-state, electrons accumulate at the sidewall of the HK dielectric from the source to the drain by the TEG. Furthermore, the high permittivity of the HK dielectric leads to an ultra-strong charge accumulation effect. As a result, an ultra-low resistance current path is formed. The specific on-resistance(Ron;sp/ is thus greatly reduced and is independent of the drift doping concentration. In the off-state, the step-dopedN pillar effectively suppresses the substrate-assisted depletion effect by charge compensation. Moreover, the reshape effect of the HK dielectric and the new electric field(E-field) peak introduced by the step-dopedN pillar enhance the drift region E-field. Hence, the BV is improved. Simulation indicates that the TEG-SD SJ LDMOS achieves an extremely low Ron;sp of 1.06 m cm2 and a BV of 217 V. Compared with the conventional SJ LDMOS, the TEG-SD SJ LDMOS decreases the Ron;sp by 77.5% and increases the BV by 33%,exhibiting a high figure of merits(FOM=BV2/Ron;sp/ of 44 MW/cm2.

A novel high figure-of-merit SOI SJ LDMOS with ultra-strong charge accumulation effect

A novel silicon-on-insulator (SOI) super-junction (SJ) LDMOS with an ultra-strong charge accumulation effect is proposed. It has two key features: an assisted-accumulation trench-type extending gate (TEG) with a high-k (HK) dielectric and a step-doped N pillar (TEG-SD SJ LDMOS). In the on-state, electrons accumulate at the sidewall of the HK dielectric from the source to the drain by the TEG. Furthermore, the high permittivity of the HK dielectric leads to an ultra-strong charge accumulation effect. As a result, an ultra-low resistance current path is formed. The specific on-resistance (R_on,sp) is thus greatly reduced and is independent of the drift doping concentration. In the off-state, the step-doped N pillar effectively suppresses the substrate-assisted depletion effect by charge compensation. Moreover, the reshape effect of the HK dielectric and the new electric field (E-field) peak introduced by the step-doped N pillar enhance the drift region E-field. Hence, the BV is improved. Simulation indicates that the TEG-SD SJ LDMOS achieves an extremely low R_on,sp of 1.06 mΩ · cm² and a BV of 217 V. Compared with the conventional SJ LDMOS, the TEG-SD SJ LDMOS decreases the R_on,sp by 77.5% and increases the BV by 33%, exhibiting a high figure of merits (FOM = BV²/R_on,sp) of 44 MW/cm².