Power transistor with metal source and method of manufacture
AssigneeSpinnaker Semiconductor, Inc.
InventorJohn P. Snyder
Life of this patent
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Abstract
A metal source power transistor device and method of manufacture is provided, wherein the metal source power transistor having a source which is comprised of metal and which forms a Schottky barrier with the body region and channel region of the transistor. The metal source power transistor is unconditionally immune from parasitic bipolar action and, therefore, the effects of snap-back and latch-up, without the need for a body contact. The ability to allow the body to float in the metal source power transistor reduces the process complexity and allows for more compact device layout.
Claims21
A metal source power transistor comprising:
- a semiconductor substrate forming a drain layer of a first conductivity type;
- a drift layer of a similar first conductivity type arranged on said drain layer;
- a body region of a second conductivity type arranged in said drift layer;
- a source region arranged in said body region, wherein said source region is formed from a metal and forms a Schottky contact to said body region;
- and
- a gate electrode arranged on said body region and said drift region.
A metal source power transistor comprising:
- a semiconductor substrate forming a drain layer of a first conductivity type;
- a drift layer of the first conductivity type arranged on the drain layer;
- a body region of a second conductivity type arranged in the drift layer;
- a source region arranged in the body region, wherein the source region includes at least one metal that forms a Schottky contact to the body region;
- and
- a gate structure arranged on the body region.
A planar metal source power transistor comprising:
- a semiconductor substrate forming a drain layer, wherein the semiconductor substrate includes silicon and wherein the drain layer includes P+ silicon;
- a drift layer arranged on the drain layer, wherein the drift layer includes epitaxially grown P-type silicon;
- a body region arranged in the drift layer, wherein the body region includes N-type silicon;
- a source region arranged in the body region, wherein the source region includes at least one metal that forms a Schottky contact to the body region and wherein the at least one metal includes platinum silicide;
- a gate structure arranged on the body region and on the drain layer wherein the gate structure includes:
- a gate insulating layer that covers a common surface of both the drift layer and the body region, wherein the gate insulating layer includes silicon dioxide;
- a gate electrode that covers the gate insulating layer, wherein the gate electrode includes boron-doped polysilicon;
- and
- an insulating sidewall spacer that covers at least one side of the gate electrode,
- wherein the insulating sidewall spacer includes silicon dioxide;
- wherein the source region and the drift region are controllably electrically connected to one another by a channel region that is controlled by a voltage on the gate structure;
- and
- wherein the body region is not contacted by a body contact allowing the body region to electrically float.
Dependencies are inferred from the claim text.