A Study of On-state Breakdown Decreasing of nLDMOSFETs by Hole Current Increase Depending on Drain Pulse Rise Time

The introduction of a p-type RESURF (REduced SURface Field) layer under an n-type drift region is a well-known means to improve the specific on-resistance (R$_{\mathbf{sp}}$) versus the off-state breakdown voltage (BV$_{\mathbf{off}}$) trade-off and reduce hot carrier injection (HCI) degradation in n-channel LDMOSFETs (nLDMOSFETs). The p-type RESURF layer also works as a punch-through stopper to maintain sufficient source/drain (S/D) negative bias capability to sub. However, the short rise time (T$_{\mathbf{r}}$) of the pulse input to drain has the disadvantage of decreasing the on-state breakdown voltage (BV$_{\mathbf{on}}$) with a large channel width layout. A mechanism for the decrease in the BV$_{\mathbf{on}}$ for an nLDMOSFET with a p-type RESURF layer is clarified, and a method to suppress the decrease in BV$_{\mathbf{on}}$ is proposed.