摘要 |
The disclosed invention provides a method for fabricating a MOSFET comprising the steps of forming a first insulation layer over a semiconductor substrate; forming a trench which bottoms on the semiconductor substrate in the first insulation layer so that the semiconductor substrate is exposed at the bottom of the trench; injecting impurities selectively under at least one end of the exposed surface of the semiconductor substrate; forming a second insulation layer to cover the bottom surface of the trench by oxidizing the exposed surface of the semiconductor substrate; forming a gate electrode over the second insulation layer inside the trench; removing the first insulation layer; forming a drain region under the surface of the semiconductor substrate so that the drain region contacts with one end of the second insulation layer, the end under which the impurities were injected; and forming a source region under the surface of the semiconductor substrate so that the source region contacts with the other end of the second insulation layer, the end opposite to the end under which the impurities were-injected.
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