Lateral FET structure with improved blocking voltage and on resistance performance and method
View Patent ↗In one embodiment, a lateral FET structure ( 30 ) is formed in a body of semiconductor material ( 32 ). The structure ( 30 ) includes a plurality non-interdigitated drain regions ( 39 ) that are coupled together with a conductive layer ( 57 ), and a plurality of source regions ( 34 ) that are coupled together with a different conductive layer ( 51 ). One or more interlayer dielectrics ( 53,54 ) separate the two conductive layers ( 51,57 ). The individual source regions ( 34 ) are absent small radius fingertip regions.
1. A lateral FET structure comprising:
a body of semiconductor material having a first conductivity type and a major surface;
first and second drift regions of a second conductivity type formed in the body of semiconductor material, wherein the first and second drift regions are spaced apart and comprise elongated stripe shapes;
a first drain contact region formed in the first drift region;
a second drain contact region formed in the second drift region, wherein the first and second drain contacts comprise elongated striped shapes;
a first pair of source regions formed in the body of semiconductor material and on opposing sides of the first drift region;
a second pair of source regions formed in the body of semiconductor material and on opposing sides of the second drift region, wherein the first and second pairs of source regions comprise elongated stripe shapes, and wherein the first and second pairs of source regions are substantially parallel to the first and second drain contacts;
a gate structure formed adjacent the first second pairs of source regions and the first and second drift regions;
a first conductivy layer formed overlying the body of semiconductor material and connecting the first and second pairs of source regions together;
a second conductive layer different than the first conductive layer formed overlying the body of semiconductor material and connecting the first and second drain contact regions together; and
an insulating layer vertically separating the first and second conductive layers.
2. The structure of claim 1 wherein the first and second conductive layers overlap.
3. The structure of claim 1 wherein the first and second conductive layer do not overlap.
4. The structure of claim 1 wherein the first and second pairs of source regions comprise elongated stripe regions having rounded tips at opposing ends.
5. The structure of claim 1 wherein the second conductive layer overlies where one of the first and second drift regions terminate at the major surface.
6. The structure of claim 1 wherein the first and second pairs of source regions and the first and second drain contact regions have equal lengths.
7. The structure of claim 1 further comprising a doped region of the first conductivity type formed in the body of semiconductor material completely surrounding the first and second drift regions.
8. The structure of claim 7 , wherein the first and second pairs of source regions are formed within the doped region.
9. The structure of claim 1 further comprising a doped region of the first conductivity type formed in the first drift region and spaced apart from first drain contact.