An integrated SOI high voltage device with a ring drain

A novel SOI high voltage device with a ring drain is developed. Junction curvature is introduced to enhance the breakdown voltage. As an example, Breakdown voltage over 600V is achieved in a SOI LDMOS on the SOI material with 3µm buried oxide and 20µm silicon. Compared with normal structure, the breakdown voltage is increased by 6.74% and the on resistance is increased merely by 2.14%.The ring drain is compatible with standard CMOS-DMOS process and the new structure can be integrated without additional process.