In accordance with the present invention, a metal oxide semiconductor
(MOS) transistor has a substrate of a first conductivity type. A drift
region of a second conductivity type extends over the substrate. A body
region of the first conductivity type is in the drift region. A source
region of the second conductivity is in the body region. A gate extends
over a surface portion of the body region. The surface portion of the
body region extends between the source region and the drift region to
form a channel region of the transistor. A drain region of the second
conductivity type is in the drift region. The drain region is laterally
spaced from the body region. A first buried layer of the second
conductivity type is between the substrate and drift region. The first
buried layer laterally extends from under the body region to under the
drain region. A second buried layer of the first conductivity type is
between the first buried layer and the drift region. The second buried
layer laterally extends from under the body region to under the drain
region.