A new degradation mechanism of current drivability and reliability of asymmetrical LDDMOSFET´s

Characteristics of asymmetrical LDDMOSFET´s fabricated by inclined n^-ion implantation have been investigated. It has been newly found that current drivability and reliability of asymmetrical LDDMOSFET´s are affected by n^-ion incident angle and the gate´s bird´s beak length. Symmetrical and shorter gate´s bird´s beak LDDMOSFET´s are more current drive capable than asymmetrical and longer ones. These results are well explained by our simple model. On the other hand, shorter drain n^-- gate overlap and gate´s bird´s beak LDDMOSFET´s are less reliable than longer ones.