NORMALLY-OFF GALLIUM NITRIDE-BASED SEMICONDUCTOR DEVICES

Jamal Ramdani

Patent

Atlas literature

Patent

US 9,385,199

NORMALLY-OFF GALLIUM NITRIDE-BASED SEMICONDUCTOR DEVICES

Jamal Ramdani

Claims

Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.

5 independent · 10 dependent

1
IndependentGaNAlGaNAlInGaNnormally-off GaN-based HEMT (gate over compressive layer, source/drain in tensile layer)
An apparatus comprising: a relaxed layer over a semiconductor substrate; a tensile layer over the relaxed layer, the tensile layer having tensile stress; a compressive layer over the relaxed layer, the compressive layer having compressive stress; source and drain regions in at least the tensile layer; and a gate over the compressive layer; wherein the compressive layer has a piezoelectric polarization that is approximately equal to or greater than a spontaneous polarization in the relaxed, tensile, and compressive layers and wherein the tensile la y er is next to the compressive layer.
1. 2
  Dependent← claim 1GaNAlGaNAlInGaNnormally-off GaN-based HEMT (gate over compressive layer, source/drain in tensile layer)
  The apparatus of Claim 1, wherein: the relaxed layer comprises gallium nitride; the tensile layer comprises aluminum gallium nitride; and the compressive layer comprises aluminum indium gallium nitride.
2. 3
  Dependent← claim 1
  The apparatus of Claim 1, wherein the piezoelectric polarization in the compressive layer is in an opposite direction than the spontaneous polarization in the compressive layer.
3. 4
  Dependent← claim 1
  The apparatus of Claim 1, wherein the compressive layer is over the tensile layer.
4. 7
  Dependent← claim 1buffer layer
  The apparatus of Claim 1, further comprising: a buﬀer layer over the substrate; wherein the relaxed layer is over the buﬀer layer.
5
Independent
canceled
6
Independent
canceled
8
IndependentGaNAlGaNAlInGaNnormally-off GaN-based semiconductor apparatus (no gate/source/drain specified)
An apparatus comprising: a relaxed layer over a semiconductor substrate; a tensile layer over the relaxed layer, the tensile layer having tensile stress; and a compressive layer over the relaxed layer, the compressive layer having compressive stress; wherein the compressive layer has a piezoelectric polarization that is approximately equal to or greater than a spontaneous polarization in the relaxed, tensile, and compressive layers; and wherein the tensile layer is next to the compressive layer.
1. 9
  Dependent← claim 8GaNAlGaNAlInGaN
  The apparatus of Claim 8, wherein: the relaxed layer comprises gallium nitride; the tensile layer comprises aluminum gallium nitride; and the compressive layer comprises aluminum indium gallium nitride.
14
Dependent← claim 13
The device of Claim 13, wherein the compressive layer is over the tensile layer.
15
Independent
canceled
16
Dependent← claim 13buffer layer
The device of Claim 13, further comprising: a buﬀer layer over the substrate; wherein the relaxed layer is over the buﬀer layer. 4

Device structures

Layer stacks claimed or described, ordered top of device to substrate.

normally-off GaN-based HEMT (gate over compressive layer, source/drain in tensile layer)

AlInGaNcompressive barrier layer

AlGaNtensile barrier layer

GaNrelaxed layer

substratesubstrate

normally-off GaN-based semiconductor apparatus (no gate/source/drain specified)

AlInGaNcompressive layer

Materials

Materials described outside the worked examples.

gallium nitride

GaN

Relaxed Layer

Buffer Layer Or Relaxed Layer

aluminum gallium nitride

AlGaN

Reported properties

Performance values and ranges asserted in the specification or claims.

Property	Value	Material
AlInGaN compressive layer indium mole fraction range (claim)	0.2–0.25	AlInGaN
AlGaN tensile layer aluminum mole fraction range (description)	0.1–0.3

Why these are connected

Related documents with shared materials, methods, properties, or citations.

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