High voltage field effect device and method

Methods and apparatus are provided for a MOSFET exhibiting increased source-drain breakdown voltage (BVdss). Source (S) and drain (D) are spaced apart by a channel underlying a gate and one or more carrier drift spaces (′) serially located between the channel and the source (′) or drain (′). A buried region (′) of the same conductivity type as the drift space (′) and the source (′) or drain (′) is provided below the drift space (′), separated therefrom in depth by a narrow gap (′) and ohmically coupled to the source (′) or drain (′). Current flow through the drift space produces a potential difference (Vt) across this gap (′). As the S-D voltage (Vo) and current (, Io) increase, this difference (Vt) induces high field conduction between the drift space (′) and the buried region (′) and diverts part (, It) of the S-D current (, Io) through the buried region (′) and away from the near surface portions of the drift space (′) where breakdown generally occurs. Thus, BVdss is increased.