Drift region doping effects on characteristics and reliability of high-voltage n-type metal-oxide-semiconductor transistors

In this study, off-state breakdown voltage (V_BD) and hot-carrier-induced degradation in high-voltage n-type metal-oxide-semiconductor transistors with various BF₂ implantation doses in the n- drift region are investigated. Results show that a higher BF₂ implantation dose results in a higher V_BD but leads to a greater hot-carrier-induced device degradation. Experimental data and technology computer-aided design simulations suggest that the higher V_BD is due to the suppression of gate-induced drain current. On the other hand, the greater hot-carrier-induced device degradation can be explained by a lower net donor concentration and a different current-flow path, which is closer to the Si-SiO₂ interface.