A dual body SOI structure for mixed analog-digital mode circuits

A new silicon-on-insulator (SOI) structure for mixed analog-digital applications is proposed where analog and digital MOSFET's are independently optimized. Two types of field oxide are introduced so that the body bias of analog devices can be effectively controlled whereas the channel region for digital devices is fully depleted. From measurements of the body related device characteristics such as the output resistance, the variation of threshold voltage and transconductance, 1/f noise, body resistance, and the self-heating effect, it is shown that the proposed structure is promising for SOI technology in mixed analog-digital mode circuit applications.