Iii-v hemt devices
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsMasahiro Sugimoto, Tetsu Kachi, Yoshitaka Nakano, Tsutomu Uesugi, Hiroyuki Ueda, Narumasa Soejima
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Abstract
A semiconductor device has a stacked structure in which a p-GaN layer, an SI-GaN layer, and an AlGaN layer are stacked, and has a gate electrode that is formed at a top surface side of the AlGaN layer. A band gap of the AlGaN layer is wider than a band gap of the p-GaN layer and the SI-GaN layer. Moreover, impurity concentration of the SI-GaN layer is less than 1×1017 cm−3. Semiconductor devices including III-V semiconductors may have a stable normally-off operation.
Claims11
1-12. (canceled)
A transistor comprising:
- a first layer;
- a second layer stacked on a top surface of the first layer;
- a surface layer stacked on a top surface of the second layer;
- and
- a gate electrode formed at a top surface side of the surface layer;
- wherein the first layer comprises a first III-V nitride semiconductor,
- the second layer comprises a second III-V nitride semiconductor having a second conductivity type,
- the surface layer comprises a III-V nitride semiconductor having a first conductivity type different from the second conductivity type, and
- a band gap of the second III-V nitride semiconductor is wider than a band gap of the first III-V nitride semiconductor.
A transistor comprising:
- a first layer;
- a plurality of units of layers, wherein each of the units of layers comprises a second layer and an upper layer stacked on a top surface of the second layer, and each of the units of layers is stacked on a top surface of a lower unit of layers;
- and
- a gate electrode formed at a top surface side of the uppermost unit of layers;
- wherein the first layer comprises a first III-V nitride semiconductor,
- the second layer comprises a second III-V nitride semiconductor having a second conductivity type,
- the upper layer comprises a III-V nitride semiconductor having a first conductivity type different from the second conductivity type, and
- a band gap of the second III-V nitride semiconductor is wider than a band gap of the first III-V nitride semiconductor.
A method for manufacturing a transistor having a first layer, a second layer stacked on a top surface of the first layer, a surface layer stacked on a top surface of the second layer, and a gate electrode formed at a top surface side of the surface layer, the method comprising:
- growing the second layer on the top surface of the first layer by epitaxial growth;
- growing the surface layer on the top surface of the second layer by epitaxial growth;
- and
- forming the gate electrode at the top surface side of the surface layer;
- wherein the first layer comprises a first III-V nitride semiconductor,
- the second layer comprises a second III-V nitride semiconductor having a second conductivity type,
- the surface layer comprises a III-V nitride semiconductor having a first conductivity type different from the second conductivity type, and
- a band gap of the second III-V nitride semiconductor is wider than a band gap of the first III-V nitride semiconductor.
A method for manufacturing a transistor having a first layer, a plurality of units of layers, and a gate electrode formed at a top surface side of the uppermost unit of layers, wherein each of the units of layers comprises a second layer and an upper layer stacked on a top surface of the second layer, and each of the units of layers is stacked on a top surface of a lower unit of layers, the method comprising:
- growing the second layer on the top surface of the first layer by epitaxial growth;
- growing the upper layer on a top surface of the second layer by epitaxial growth;
- growing the second layer on a top surface of the upper layer by epitaxial growth;
- growing the upper layer on a top surface of the second layer by epitaxial growth;
- repeating the growing the second layer and growing the upper layer for a predetermined cycle;
- and
- forming the gate electrode at a top surface side of an uppermost upper layer;
- wherein the first layer comprises a first III-V nitride semiconductor,
- the second layer comprises a second III-V nitride semiconductor having a second conductivity type,
- the upper layer comprises a III-V nitride semiconductor having a first conductivity type different from the second conductivity type, and
- a band gap of the second III-V nitride semiconductor is wider than a band gap of the first III-V nitride semiconductor.
Dependencies are inferred from the claim text.