Monolithic bi-directional current conducting device and method of making the same
AssigneeNorthrop Grumman Systems Corporation
InventorJOHN V. VELIADIS
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Abstract
A monolithic bi-directional device provides bi-directional power flow and bi-directional blocking of high-voltages. The device includes a first transistor having a first drain formed over a first channel layer that overlays a substrate, and a second transistor that includes a second drain formed over a second channel layer that overlays the substrate. The substrate forms a common source for both the first transistor and the second transistor.
Claims12
1-9. (canceled)
A method of making a monolithic bi-directional device for providing bi-directional power flow and bi-directional blocking of high-voltages, the method comprising:
- forming a semiconductor structure stack over a doped substrate, the semiconductor structure stack comprising a heavily doped contact interface layer overlying a lightly doped drift layer overlying a medium doped channel layer;
- performing an etching process on the semiconductor structure stack to form a first set of drain pillars formed over a first portion of the medium doped channel layer, and a second set of drain pillars formed over a second portion of the medium doped channel layer;
- forming drain contacts on the first set of drain pillars and the second set of drain pillars, and first gate contacts between the first set of drain pillars and in contact with the first portion of the medium doped channel layer and second gate contacts between the second set of drain pillars and in contact with the second portion of the medium doped channel layer;
- and
- forming a source contact on the doped substrate.
A method of making a monolithic device for providing bi-directional power flow and bi-directional blocking of high-voltages, the method comprising:
- forming a medium doped channel layer over a doped substrate;
- forming a lightly doped drift layer over the medium doped channel layer;
- forming a heavily doped contact interface layer over the lightly doped drift layer;
- performing a first etching process to remove portions of the heavily doped contact interface layer and the lightly doped drift layer to form a first generally circular or generally rectangular trench opening that defines a first active area mesa and a second generally circular or generally rectangular trench opening that defines a second active area mesa;
- performing a second etching process to form a first set of drain pillars in the first active area mesa, and a second set of drain pillars in the second active area mesa;
- forming an isolation region down through the medium doped channel layer to the substrate between the first set of drain pillars and the second set of drain pillars to electrically isolate the first set of drain pillars from the second set of drain pillars and the medium doped channel layer;
- forming drain contacts on the first set of drain pillars and the second set of drain pillars, and first gate contacts between pillars of the first set of drain pillars and in contact with a first portion of the medium doped channel layer and second gate contacts between pillars of the second set of drain pillars and in contact with a second portion of the medium doped channel layer;
- and
- forming a source contact on the doped substrate that forms a common source.
Dependencies are inferred from the claim text.