Appeal No. 2004-0581
Application No. 09/041,105
wherein during operation, the second conduction-type
well relatively low in impurity density is capable of being
depleted.
10. A semiconductor device having a separation
structure for high withstand-voltage comprising:
a first-conduction-type semiconductor substrate;
a second-conduction-type well relatively high in
impurity density, said second-conduction-type well being
formed on a surface of said first-conduction-type
semiconductor substrate;
a first-conduction-type epitaxial region formed on said
first-conduction-type semiconductor substrate above said
second-conduction-type well; and
a second-conduction-type well relatively low in
impurity density, said second-conduction-type well being
formed in said first-conduction-type epitaxial region at a
depth to reach said second-conduction-type well relatively
high in impurity density in an area including said second-
conduction-type well relatively high in impurity density
except for a predetermined portion above said second-
conduction-type well relatively high in impurity density,
wherein said second conduction type well relatively low in
impurity density extends substantially beyond an outer
peripheral portion of said second conduction type well
relatively high in impurity density,
wherein during operation, the second conduction-type
well relatively low in impurity density is capable of being
depleted.
3
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 Next
Last modified: November 3, 2007