Performance Optimization of LDMOS Transistor with Dual Gate Oxide for Mixed-Signal Applications

Abstract

This paper reports the optimized mixed-signal performance of a high-voltage (HV) laterally double-diffused metaloxide-semiconductor (LDMOS) field-effect transistor (FET) with a dual gate oxide (DGOX). The fabricated device is based on the split-gate FET concept. In addition, the gate oxide on the source-side channel is thicker than that on the drain-side channel. The experiment results showed that the electrical characteristics are strongly dependent on the source-side channel length with a thick gate oxide. The digital and analog performances according to the source-side channel length of the DGOX LDMOS device were examined for circuit applications. The HV DGOX device with various source-side channel lengths showed reduced by maximum 37% on-resistance (R ON ) and 50% drain conductance (g ds ). Therefore, the optimized mixed-signal performance of the HV DGOX device can be obtained when the source-side channel length with a thick gate oxide is shorter than half of the channel length.