Semiconductor device has high-voltage transistor well and low voltage transistor well which are formed on common substrate separated by isolation structure extending initial depth into substrate

摘要

The semiconductor device has high-voltage transistor well and low voltage transistor well which are formed on a common substrate separated by an isolation structure extending an initial depth into the substrate. The doping material of primary conductivity type is simultaneously implanted into a channel region of the low-voltage transistor well and a drain region for the high-voltage transistor well using mask and implantation process. An independent claim is included for method for forming low-voltage and high-voltage transistors.