Integrated heterostructures of group III-V nitride semiconductor materials including epitaxial ohmic contact comprising multiple quantum well

An ohmic contact for a semiconductor device formed of Group III-V nitride compound semiconductor materials and including a first layer comprising aluminum nitride or aluminum gallium nitride, and which is doped a predetermined conductivity type, said ohmic contact comprising:

• a second layer comprising a multiple quantum well of alternating layers of aluminum nitride or aluminum gallium nitride, and gallium nitride or an alloy thereof on said first layer, which is doped said predetermined conductivity type, wherein the thickness of said layers of gallium nitride or an alloy thereof increases from adjacent said first layer to opposite said first layer;
• a third layer comprising gallium nitride or an alloy thereof on said second layer, and doped said predetermined conductivity type;
• and
• a conductor layer on said third layer.

An integrated heterostructure device of Group III-V nitride compound semiconductor materials, comprising:

• a first layer comprising a first binary Group III-V nitride compound semiconductor material or an alloy thereof, said first binary Group III-V nitride compound semiconductor material or an alloy thereof comprising a first Group III element and nitrogen, and which is doped a predetermined conductivity type;
• a second layer comprising a multiple quantum well including alternating layers of said first binary Group III-V nitride compound semiconductor material or an alloy thereof, and a second binary Group III-V nitride compound semiconductor material or an alloy thereof, on said first layer, said alternating layers of said first binary group III-V nitride compound semiconductor material or an alloy thereof and said second binary Group III-V nitride compound semiconductor material or an alloy thereof being doped said predetermined conductivity type, wherein the thickness of said layers of said second binary Group III-V nitride compound semiconductor material or an alloy thereof increases from adjacent said first layer to opposite said first layer;
• a third layer comprising said second binary Group III-V nitride compound semiconductor material or an alloy thereof, on said second layer, said second binary Group III-V nitride compound semiconductor material or an alloy thereof being doped said predetermined conductivity type;
• and
• a conductor layer on said third layer.

An integrated heterostructure device of Group III-V nitride compound semiconductor materials, comprising:

• a first layer comprising aluminum nitride or aluminum gallium nitride, and which is doped a predetermined conductivity type;
• a second layer comprising a multiple quantum well of alternating layers of aluminum nitride or aluminum gallium nitride, and gallium nitride or an alloy thereof on said first layer, which is doped said predetermined conductivity type, wherein the thickness of said layers of gallium nitride or an alloy thereof increases from adjacent said first layer to opposite said first layer;
• a third layer comprising gallium nitride or an alloy thereof on said second layer, and doped said predetermined conductivity type;
• and
• a conductor layer on said third layer.

An integrated heterostructure device comprising:

• a substrate comprising monocrystalline semiconductor material;
• a buffer layer comprising a non-nitride monocrystalline material on said substrate;
• and
• an integrated heterostructure of Group III-V nitride compound semiconductor materials on said buffer layer, wherein said integrated heterostructure comprises an ohmic contact of Group III-V nitride compound semiconductor materials and wherein said ohmic contact comprises:
• a first layer comprising a first binary Group III-V nitride compound semiconductor material or an alloy thereof, said first binary Group III-V nitride compound semiconductor material or an alloy thereof comprising a first Group III element and nitrogen, and which is doped a predetermined conductivity type;
• a second layer comprising a multiple quantum well including alternating layers of said first binary group III-V nitride compound semiconductor material or an alloy thereof, and a second binary Group III-V nitride compound semiconductor material or an alloy thereof, on said first layer, said alternating layers of said first binary group III-V nitride compound semiconductor material or an alloy thereof and said second binary Group III-V nitride compound semiconductor material or an alloy thereof being doped said predetermined conductivity type, wherein the thickness of said layers of said second binary Group III-V nitride compound semiconductor material or an alloy thereof increases from adjacent said first layer to opposite said first layer;
• and
• a third layer comprising said second binary Group III-V nitride compound semiconductor material or an alloy thereof, on said second layer, said second binary Group III-V nitride compound semiconductor material or an alloy thereof being doped said predetermined conductivity type, wherein said third layer is on said buffer layer.

An integrated heterostructure device comprising:

• a substrate comprising monocrystalline silicon carbide;
• a buffer layer comprising monocrystalline zinc oxide on said substrate;
• and
• an integrated heterostructure of Group III-V nitride compound semiconductor materials on said buffer layer, wherein said integrated heterostructure further comprises an ohmic contact of Group III-V nitride compound semiconductor materials and wherein said ohmic contact comprises:
• a first layer comprising aluminum nitride or aluminum gallium nitride, and which is doped a predetermined conductivity type;
• a second layer comprising a multiple quantum well of alternating layers of aluminum nitride or aluminum gallium nitride, and gallium nitride or an alloy thereof on said first layer, which is doped said predetermined conductivity type, wherein the thickness of said layers of gallium nitride or an alloy thereof increases from adjacent said first layer to opposite said first layer;
• a third layer comprising gallium nitride or an alloy thereof on said second layer, and doped said predetermined conductivity type, wherein said third layer is on said buffer layer.

A bipolar transistor, comprising:

• a base, an emitter and a collector, each of which includes a first layer comprising a first binary Group III-V nitride compound semiconductor material or an alloy thereof, said first binary Group III-V nitride compound semiconductor material or an alloy thereof comprising a first Group III element and nitrogen;
• and
• an ohmic contact for each of said base, said emitter and said collector, each ohmic contact comprising:
• a second layer comprising a multiple quantum well including alternating layers of said first binary Group III-V nitride compound semiconductor material or an alloy thereof, and a second binary Group III-V nitride compound semiconductor material or an alloy thereof, on said first layer, wherein the thickness of said layers of said second binary Group III-V nitride compound semiconductor material or an alloy thereof increases from adjacent said first layer to opposite said first layer;
• a third layer comprising said second binary Group III-V nitride compound semiconductor material or an alloy thereof, on said second layer;
• and
• a conductor layer on said third layer.

A field effect transistor comprising:

• spaced apart source and drain regions and a channel region therebetween;
• a gate adjacent said channel, said gate including a first layer comprising a first binary Group III-V nitride compound semiconductor material or an alloy thereof, said first binary Group III-V nitride compound semiconductor material or an alloy thereof comprising a first Group III element and nitrogen, and which is doped a predetermined conductivity type;
• and
• an ohmic contact for said gate, said ohmic contact comprising:
• a second layer comprising a multiple quantum well including alternating layers of said first binary Group III-V nitride compound semiconductor material or an alloy thereof, and a second binary Group III-V nitride compound semiconductor material or an alloy thereof, on said first layer, said alternating layers of said first binary group III-V nitride compound semiconductor material or an alloy thereof and said second binary Group III-V nitride compound semiconductor material or an alloy thereof being doped said predetermined conductivity type, wherein the thickness of said layers of said second binary Group III-V nitride compound semiconductor material or an alloy thereof increases from adjacent said first layer to opposite said first layer;
• a third layer comprising said second binary Group III-V nitride compound semiconductor material or an alloy thereof, on said second layer, said second binary Group III-V nitride compound semiconductor material or an alloy thereof being doped said predetermined conductivity type;
• and
• a conductor layer on said third layer.