A 300-V Ultra-Low-Specific On-Resistance High-Side p-LDMOS With Auto-Biased n-LDMOS for SPIC

Abstract

In this paper, a high-side p-channel LDMOS (p-LDMOS) with an auto-biased n-channel LDMOS (n-LDMOS) based on Triple-RESURF technology is proposed. The p-LDMOS utilizes both carriers to conduct the on-state current; therefore, the specific on-resistance ( $R_{{\rm on},{\rm sp}}$ ) can be much reduced because of much higher electron mobility. The simulation result shows that the proposed 300-V p-LDMOS obtains a $R_{{\rm on},{\rm sp}}$ of 16.97 mΩ/cm2, which is about 65% reduced compared with the Triple-RESURF silicon limit and is comparable to an optimized n-LDMOS (BV = 340 V, $R_{{\rm on},{\rm sp}} = 18$ mΩ/cm2 ). In addition, due to larger current capability, the active area of the proposed p-LDMOS is only about one third of an optimized Triple-RESURF p-LDMOS. The turn-on ( $t_{r}$ ) and turn-off time ( $t_{f}$ ) are reduced by 51.2% and 40.0%, compared to the optimized Triple-RESURF p-LDMOS, respectively.