Semiconductor devices and fabrication methods thereof

摘要

A semiconductor device is provided. The semiconductor device includes a semiconductor substrate; and a body region and a drift region formed in the semiconductor substrate. The semiconductor device also includes a bulk region and a source region formed in the body region. Further, the semiconductor device includes a drain region and a first shallow trench isolation structure having a ladder-like bottom formed in the drift region. Further, the semiconductor device also includes a gate structure spanning over an edge of the body region and an edge of the drift region formed on the semiconductor substrate and covering a portion of the first shallow trench isolation structure.

主权项

1. A method for fabricating a semiconductor device, comprising:
providing a semiconductor substrate; forming a plurality of trenches with different depths in the semiconductor substrate; forming a first oxide layer by oxidizing the semiconductor substrate between adjacent trenches; forming a first shallow trench isolation structure by filling the trenches with different depths with dielectric material; forming a body region and a drift region, wherein the first shallow trench isolation structure is in the drift region; forming a bulk region and a source region in the body region and a drain region in the drift region at one side of the first shallow trench isolation structure away from the body region; and forming a gate structure spanning over an edge of the body region and an edge of the drift region and covering a portion of the first shallow trench isolation structure on the semiconductor substrate.