Reliability improvement in field-MOS FETs with thick gate oxide for 300-V applications

The reliability of high performance Field-PMOS FET with thick gate oxide was improved. By reducing the amount of charge in the insulating film, RESURF effect was well performed in the drift region to obtain BV DSS over 350 V. Gate oxide breakdown voltage was found to decrease at AC high slew rate, and its reduction was suppressed with the fluorine termination. NBTI shift was also reduced within 15% in a product lifetime. The fluorine termination works as suppressing parasitic charge traps effect in the oxide.