It is an object to obtain a semiconductor device comprising a channel stop structure
which is excellent in an effect of stabilizing a breakdown voltage and a method
of manufacturing the semiconductor device. A silicon oxide film (2) is formed
on an upper surface of an N-;-type silicon substrate (1). An
N+-type impurity implantation region (4) is formed in an upper
surface (3) of the N-;-type silicon substrate (1) in a
portion exposed from the silicon oxide film (2). A deeper trench (5)
than the N+-type impurity implantation region (4) is formed in
the upper surface (3) of the N-;-type silicon substrate (1).
A silicon oxide film (6) is formed on an inner wall of the trench (5).
A polysilicon film (7) is formed to fill in the trench (5). An aluminum
electrode (8) is formed on the upper surface (3) of the N-;-type
silicon substrate (1). The aluminum electrode (8) is provided in
contact with an upper surface of the polysilicon film (7) and the upper
surface (3) of the N-;-type silicon substrate (1). The
aluminum electrode (8) is extended over the silicon oxide film (2)
to constitute a field plate.
