Power Semiconductor device having high breakdown voltage, low on-resistance and small switching loss

摘要

In accordance with one embodiment of the present invention, a power semiconductor device includes a first drift region of a first conductivity type extending over a semiconductor substrate. The first drift region has a lower impurity concentration than the semiconductor substrate. A second drift region of the first conductivity type extends over the first drift region, and has a higher impurity concentration than the first drift region. A plurality of stripe-shaped body regions of a second conductivity type are formed in an upper portion of the second drift region. A third region of the first conductivity type is formed in an upper portion of each body region so as to form a channel region in each body region between the third region and the second drift region. A gate electrode laterally extends over but is insulated from: (i) the channel region in each body region, (ii) a surface area of the second drift region between adjacent stripes of body regions, and (iii) a surface portion of each source region.