| 摘要 |
PURPOSE:To contrive reduction in cost of formation of layers and simplification of manufacturing process by a method wherein a buried channel normally-OFF type MOSFET is used as a vertical type MOSFET, thereby enabling to reduce the thickness of an epitaxially grown layer. CONSTITUTION:The MOSFET to be used for power is composed of an oxide Si layer 22 provided on a metal substrate 21, a drain 23 which is used as an N<+> Si region formed on the region ranging from above the layer 22 to the entire surface of the metal substrate, a source 24 which is used as an N<+> type Si region formed on said layer 22, and an N type Si region 25 provided adjoining to the drain 23 surrounding the source 24. On the surface of said region 25, a gate electrode 27 is formed through the intermediary of a surface insulating film 26. Also, the layer 22 is buried in such a manner that it comes in contact with the depletion layer which is extended from the electrode 27 when the electrode 27 and the source 24 are placed in the state of short-circuit. According to this constitution, the thickness of the layer 23 can be reduced remarkably and the manufacturing process can also be simplified, thereby enabling to cut down the cost of manufacture. |
