A new isolation technology with p+ diffusion ring used in reverse conducting GCT

In this paper, the advantages and disadvantages of the pnp separation of reverse conducting gate commutated thyristor (RC-GCT) are analyzed. Based on the results, a new separation method with p⁺ diffusion ring is presented, and the forward blocking characteristic of the RC-GCT is analyzed by using MEDICI simulator. The results show that the new separation method used in RC-GCT devices can improve the forward blocking characteristic of RC-GCT, and has no influence on the gate reverse characteristics and the commutation current, and increase hardly the complexity of process simultaneity. Only reduce the effective cathode areas of RC-GCT. Lastly, the width of p⁺ diffusion ring and the space between the p+ diffusion ring and p base region are optimized.