Super-junction voltage sustaining layer with alternating semiconductor and High-K dielectric regions
First Claim
1. A semiconductor device comprising:
- a substrate contact layer comprising a semiconductor of a first conductivity type, wherein said contact layer has one planar contact plane on one of its side;
a device feature layer comprising a semiconductor of a second conductivity type, wherein said device feature layer has one planar device feature plane parallel to said contact plane;
a voltage-sustaining layer for sustaining a reverse high voltage disposed between said contact plane and said device feature plane;
wherein said voltage-sustaining layer comprises a plurality of closely packed cells, each cell having only one semiconductor region of a first conductivity type and one dielectric region, a size of a cross-section of each cell parallel to said device feature plane being smaller than a distance between said contact plane and said device feature plane, and, both said semiconductor region and said dielectric region in said cell of said voltage-sustaining layer extending between said contact plane and said device feature plane;
wherein a value of an electric permittivity of said dielectric region in said cell of said voltage sustaining layer is much larger than a value of a electric permittivity of said semiconductor region in said cell of said voltage sustaining layer;
wherein in area of a cross section of said dielectric region parallel to said device feature plane is in the same order of magnitude of an area of a cross section of said semiconductor region parallel to said device feature plane;
wherein a ratio of said cross section of said dielectric region to said cross section of said semiconductor region becomes smaller with increasing distance from said device feature plane to said contact plane;
wherein the semiconductor region of each cell is fully depleted under a reverse voltage close to a breakdown voltage applied across said substrate contact layer and said device feature layer, and in most of an area of each cell, a component of an electric field parallel to said device feature plane;
wherein, under said breakdown voltage, electric fluxes generated by charges of the depleted semiconductor region of each cell beyond a distance to said device feature plane smaller than the size of said cell are terminated by said device feature plane through said dielectric region.
1 Assignment
0 Petitions
Accused Products
Abstract
A semiconductor power device includes a device feature layer, a substrate contact layer and a voltage-sustaining layer between them. The voltage-sustaining layer includes alternating semiconductor and high permittivity dielectric regions, where each region extends from the device feature layer to the substrate contact layer. Due to the flux of charges transported dominantly through the dielectric regions, the whole voltage-sustaining layer behaves like a semiconductor having a much higher electric permittivity than that of the semiconductor itself, so that the field produced by the ionized impurities of the semiconductor regions can be much higher than that of the conventional one for sustaining the same reverse voltage, and the specific on-resistance can be lower than that of the conventional one. The use of high permittivity dielectric regions can also be applied to the charge-balance structure, i.e., to COOLMOST.
23 Citations
9 Claims
-
1. A semiconductor device comprising:
-
a substrate contact layer comprising a semiconductor of a first conductivity type, wherein said contact layer has one planar contact plane on one of its side; a device feature layer comprising a semiconductor of a second conductivity type, wherein said device feature layer has one planar device feature plane parallel to said contact plane; a voltage-sustaining layer for sustaining a reverse high voltage disposed between said contact plane and said device feature plane; wherein said voltage-sustaining layer comprises a plurality of closely packed cells, each cell having only one semiconductor region of a first conductivity type and one dielectric region, a size of a cross-section of each cell parallel to said device feature plane being smaller than a distance between said contact plane and said device feature plane, and, both said semiconductor region and said dielectric region in said cell of said voltage-sustaining layer extending between said contact plane and said device feature plane; wherein a value of an electric permittivity of said dielectric region in said cell of said voltage sustaining layer is much larger than a value of a electric permittivity of said semiconductor region in said cell of said voltage sustaining layer; wherein in area of a cross section of said dielectric region parallel to said device feature plane is in the same order of magnitude of an area of a cross section of said semiconductor region parallel to said device feature plane; wherein a ratio of said cross section of said dielectric region to said cross section of said semiconductor region becomes smaller with increasing distance from said device feature plane to said contact plane; wherein the semiconductor region of each cell is fully depleted under a reverse voltage close to a breakdown voltage applied across said substrate contact layer and said device feature layer, and in most of an area of each cell, a component of an electric field parallel to said device feature plane; wherein, under said breakdown voltage, electric fluxes generated by charges of the depleted semiconductor region of each cell beyond a distance to said device feature plane smaller than the size of said cell are terminated by said device feature plane through said dielectric region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification