An ON-resistance closed form for VDMOS devices

An analytical ON-resistance expression for different designs of VDMOS (vertically diffused metal-oxide-semiconductor) devices which takes into consideration the two-dimensional (2-D) nature of the current flow is obtained. This expression differs from other models that overestimate this resistance for large cell spacings. This formulation is in close agreement with experimental points obtained from the interdigitated fabricated structures and with 2-D simulations. Moreover, the effect of a two-level oxide thickness on the ON resistance has been investigated for the interdigitated case.<<ETX>>