摘要 |
A semiconductor device having an EDMOS transistor and a method for forming the same are provided. The semiconductor device includes source and drain regions formed separately in a semiconductor substrate, a first gate insulating layer filling a trench formed in the substrate between the source and drain regions, the first gate insulating layer being adjacent to the drain region and separated from the source region, a second gate insulating layer formed over the substrate between the first gate insulating layer and the source region, the second gate insulating layer being thinner than the first gate insulating layer, a gate electrode formed over the first and second gate insulating layers, and a doped drift region formed in the substrate under the first gate insulating layer, the doped drift region being in contact with the drain region. This reduces the planar area of the EDMOS transistor, thereby achieving highly integrated semiconductor devices.
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