Method of manufacturing a semiconductor device and the semiconductor device
AssigneeRenesas Electronics Corporation
InventorYuji ANDO
Life of this patent
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Abstract
Characteristics of a high electron mobility transistor are improved. A stack having an n-type contact layer (n-type AlGaN layer), an electron supply layer (undoped AlGaN layer), and a channel layer (undoped GaN layer) is formed in a growth mode over a Ga plane parallel with a [0001] crystal axis direction. Then, after turning the stack upside down so that the n-type contact layer (n-type AlGaN layer) is situated to the upper surface and forming a trench, a gate electrode is formed by way of a gate insulation film. By stacking the channel layer (undoped GaN layer) and the electron supply layer (undoped AlGaN layer) successively in a [000-1] direction, (1) normally off operation and (2) increase of withstanding voltage can easily be compatible with each other.
Claims18
A method of manufacturing a semiconductor device including the steps of:
- (a) epitaxially growing a second nitride semiconductor layer over a first nitride semiconductor layer in a [0001] direction, thereby forming a stack comprising the first nitride semiconductor layer and the second nitride semiconductor layer, and
- (b) disposing the stack such that the [000-1] direction of the stack becomes upward and forming a gate electrode on the side of the first nitride semiconductor layer, in which
- the first nitride semiconductor layer has a band gap larger than a band gap of the second nitride semiconductor.
A semiconductor device including:
- a first nitride semiconductor layer formed over a substrate,
- a second nitride semiconductor layer formed over the first nitride semiconductor layer and having a band gap larger than a band gap of the first nitride semiconductor layer,
- a gate electrode disposed over the second nitride semiconductor layer,
- a first electrode disposed on at least one side of the gate electrode in a portion over the second nitride semiconductor layer, and
- a first semiconductor region containing impurities formed in one of the second nitride semiconductor layer and the first nitride semiconductor layer on both sides of the gate electrode, in which
- a crystal axis direction from the first nitride semiconductor layer to the second nitride semiconductor layer in a stacked portion of the first nitride semiconductor layer and the second nitride semiconductor layer is a [000-1] direction.
Dependencies are inferred from the claim text.