THERMALLY STABLE AMMONIA GAS SENSOR USING ZnO-FUNCTIONALIZED AIGaN/GaN HETEROSTRUCTURE TRANSISTOR

Soohwan Jang

Patent

Atlas literature

Patent

US 10,488,364

THERMALLY STABLE AMMONIA GAS SENSOR USING ZnO-FUNCTIONALIZED AIGaN/GaN HETEROSTRUCTURE TRANSISTOR

Soohwan Jang

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 · 15 dependent

1
IndependentZnOZnO-functionalized HEMT ammonia sensor (claim 1 variant)
A sensor for detecting at least one of ammonia and NxOy, the sensor comprising: a transistor having a gate, a drain, and a source, wherein the gate comprises a layer of ammonia-detecting material attached functionally to a substrate of the transistor, wherein the ammonia detecting material comprises zin c oxide (ZnO) attached to the transistor, thereby eﬀectively functionalizing the transistor, and at least a portion of a surface of the ZnO is exposed to an external environment to detect ammonia. Currently amended
1. 3
  Dependent← claim 1ZnOTiO₂ITOWO₃AZO
  The sensor according to claim 1, wherein the ammonia detecting material [[is]] comprises ﬁlms or nanostructure type metal oxides including one or more of TiO 2, ITO, ZnO, W 0 3 and AZO. Currently amended
2. 4
  Dependent← claim 1ZnO-functionalized HEMT ammonia sensor (claim 1 variant)
  The sensor according to claim 1, wherein the transistor is a high electron mobility transistor (H EMT). Original
3. 7
  Dependent← claim 1ZnO-functionalized HEMT ammonia sensor (claim 1 variant)
  The sensor according to claim 1, further comprising a passivation layer between the transistor and the ammonia detecting material. Original
4. 8
  Dependent← claim 1ZnOZnO-functionalized HEMT ammonia sensor (claim 1 variant)
  The sensor of according to claim 1, wherein the ammonia detecting material is a layer of zin c oxide (ZnO) nanorods between the source and drain of the transistor. Original
2
Independent
Canceled
9
IndependentGaNAlGaNZnOAlGaN/GaN HEMT gas sensor with ZnO ammonia adsorbing layer (claim 9 variant)
A gas sensor, comprising: a gallium nitride (GaN) layer; an aluminum gallium nitride (AIGaN) layer disposed on the GaN layer; a source and a drain disposed on the AIGaN layer; and an ammonia adsorbing layer directly disposed on the AIGaN layer and placed between the source and the drain, wherein the ammonia adsorbing la y er comprises zin c oxide (ZnO) and wherein at least a portion of a surface of the ZnO is exposed to an external environment to detect ammonia. Currently amended
1. 10
  Dependent← claim 9TiO₂ITOWO₃AZO
  The gas sensor according to claim 9, wherein the ammonia adsorbing layer further comprises at least one of, titanium dioxide (TiO 2), indium tin oxide (ITO), tungsten trioxide (W 0 3), and aluminum-doped zin c oxide (AZO). Currently amended
2. 12
  Dependent← claim 9AlGaN/GaN HEMT gas sensor with ZnO ammonia adsorbing layer (claim 9 variant)
  The gas sensor according to claim 9, further comprising a spacer placed between the source and the ammonia adsorbing layer and between the drain and the ammonia adsorbing layer. Currently amended
11
Independent
Canceled
20
IndependentGaNAlGaNZnOSi₃N₄metal layer (Ti/Al/Ni/Au)AlGaN/GaN HEMT gas sensor with ZnO nanorods and SiN spacer (claim 20 variant)
A gas sensor, comprising: a substrate; a gallium nitride (G aN) layer disposed on the substrate; an aluminum gallium nitride (A I GaN) layer disposed on the G aN layer; a source and a drain disposed on the A l GaN layer; zin c oxide (ZnO) nanorods directly disposed on the A I GaN layer and placed between the source and the drain; a silicon nitride spacer placed between the source and the ZnO nanorods and between the drain and the ZnO nanorods; and a contact pad disposed on the source and the drain, wherein the source and the drain comprise a metal layer that forms an ohmic contact with the AIGaN layer, wherein at least a portion of a surface of the ZnO nanorods is exposed to an external environment to detect ammonia. Currently amended

Worked examples

Embodiments described in the patent, grouped by the materials and process steps they use.

ZnO nanorod growth (hydrothermal method)

example section example

1 material1 process step

ZnO nanorods are grown using a hydrothermal method described as low cost, non-toxic, low temperature, and scalable, for use as sensing material on the gate of an AlGaN/GaN HEMT. No specific procedural parameters (temperatures, times, precursors) are given in the text provided.

Device structures

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

ZnO-functionalized HEMT ammonia sensor (claim 1 variant)

metal layer (Ti/Al/Ni/Au)source/drain contacts

Si₃N₄spacer/passivation

ZnOgate/ammonia-detecting layer

AlGaNbarrier layer

GaNbase channel layer

sapphiresubstrate

Materials

Materials described outside the worked examples.

titanium dioxide

TiO₂

Alternative Ammonia-Detecting Metal Oxide

indium tin oxide

ITO

Reported properties

Performance values and ranges asserted in the specification or claims.

Property	Value	Material
ammonia concentration measurement range	0.1 to 2.0 ppm	ZnO
90% saturation current response time	≤1 s

Why these are connected

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

THERMALLY STABLE AMMONIA GAS SENSOR USING ZnO-FUNCTIONALIZED AIGaN/GaN HETEROSTRUCTURE TRANSISTOR | Matter42 Literature