Appeal No. 1999-2578
Application No. 08/811,363
for the channel regions and for the deep body regions of elementary functional units. This
is made possible by implanting dopant along directions tilted at angles ranging from 0 to
60 degrees with respect to a direction orthogonal to the surface of the material wherein the
dopant is to be implanted. Consequently, the tolerance on the dimension of the source
regions is not determined by the mask alignment rules, but substantially by the tolerance of
thicknesses of three layers (gate oxide, polysilicon oxide, insulating oxide), which is at
least one order of magnitude lower. Therefore, the dimension of the source region is more
finely controlled and narrower elementary functional units can be formed.
Representative independent claim 19 is reproduced as follows:
19. A high-density MOS-technology power device integrated structure
comprising a plurality of elementary functional units formed in a
semiconductor material layer of a first conductivity type covered by a
conductive insulated gate layer sandwiched between two insulating layers,
wherein each elementary functional unit comprises:
an elongated window formed in said insulated gate layer and in said
two insulating layers, having two elongated edges and two short edges, said
edges being sealed by insulating material sidewall spacers;
a heavily doped elongated deep body region of a second conductivity
type formed in the semiconductor material layer and substantially aligned
with the edges of the window;
two elongated channel regions of the second conductivity type
formed in said semiconductor material layer and extending along the
elongated edges of said window; and
two elongated source regions of the first conductivity type formed in
2
Page: Previous 1 2 3 4 5 6 7 8 Next
Last modified: November 3, 2007