High Voltage CMOS Devices

摘要

A transistor suitable for high-voltage applications is provided. The transistor is formed on a substrate having a deep well of a first conductivity type. A first well of the first conductivity type and a second well of a second conductivity type are formed such that they are not immediately adjacent each other. The well of the first conductivity type and the second conductivity type may be formed simultaneously as respective wells for low-voltage devices. In this manner, the high-voltage devices may be formed on the same wafer as low-voltage devices with fewer process steps, thereby reducing costs and process time. A doped isolation well may be formed adjacent the first well on an opposing side from the second well to provide further device isolation.