| 摘要 |
PROBLEM TO BE SOLVED: To satisfy both low ON resistance and high breakdown strength by making an area pinched by a second conductivity type drift layer to be a first conductivity type drift layer like a stripe. SOLUTION: A p+-type contact layer 11, a source electrode and a drain electrode are formed, thereby obtaining a horizontal power MOSFET having a multi-resurfacing layer which comprises a p-type drift layer 4 (second conductivity type drift layer) that is formed like a stripe from a p-type body layer 6 to an n-type drain layer 10 and an n-type drift layer 5 (first conductivity type drift layer). Before a depletion layer 14 reaches the n--type drift layer 5 constituting the p-n junction with the p--drift layer 4, the distance between the p--type drift layer 4 and an embedded oxide film 2 is selected to that the p--type drift layer 4 and n--type drift layer 5 are entirely depleted from the boundary of p-n junction between the p--type drift layer 4 and n--type drift layer 5 by means of the depletion layer 14. Thus, no area which is not depleted exists in a part of the p+-type drift layer 4. The dose of the impurity in the n-type drift layer 5 is made high. |
