Mike Chang

Lateral HVIC with 1200-V bipolar and field-effect devices

The 1200-V blocking capability of lateral high-voltage devices has been achieved through theoretical and experimental investigation. The feasibility of a 1200-V lateral n-p-n bipolar junction transistor, p-n diode, and lateral DMOSFET has been demonstrated for the first time. The on-resistance of the 1200-V DMOSFET is 4 times less than its 1200-V n-p-n BJT counterpart. The major contribution to high BJT on-resistance comes from the series JFET pinch resistance.

A self-aligned short process for insulated-gate bipolar transistors

An n-channel vertical insulated-gate bipolar transistor (IGBT) process which implements a self-aligned p/sup +/ short inside the DMOS diffusion windows is proposed and demonstrated experimentally. The salient feature of the new process is the placement of a poly-Si plug to define the diffusion window of the p/sup +/ short. Similar forward conduction characteristics and tradeoffs with turn-off time were obtained for these self-aligned short IGBTs when compared to conventional IGBTs with non-self-aligned shorts. With a resistive load and no external gate resistor, dynamic latching current was seen to increase with increasing p/sup +/ diffusion depth and electron irradiation dosage, as well as with larger p/sup +/ diffusion windows. >