III nitride semiconductor device and method of producing the same
AssigneeDowa Electronics Materials Co., Ltd.
InventorsYoshitaka Kadowaki, Tatsunori Toyota
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Abstract
Provided are a III nitride semiconductor device which can be operated at a lower voltage can be provided, in which device a good ohmic contact is achieved between the (000-1) plane side of the III nitride semiconductor layer and the electrode and a method of producing the III nitride semiconductor device. A III nitride semiconductor device of the present invention includes a plurality of protrusions rounded like domes in a predetermined region on the (000-1) plane side of the III nitride semiconductor layer; and an electrode on the upper surface of the predetermined region.
Claims15
A III nitride semiconductor device having a III nitride semiconductor layer, comprising:
- a plurality of protrusions rounded like domes in a predetermined region on the (000-1) side of the III nitride semiconductor layer, a surface of the plurality of protrusions comprising planes except for the (000-1) plane, and a height of the protrusions being 0.1 μm to 3 μm;
- and
- an electrode on the upper surface of the predetermined region.
A III nitride semiconductor device comprising:
- a support;
- and a first conductivity-type III nitride semiconductor layer, an active layer, and a second conductivity-type III nitride semiconductor layer sequentially placed on the support,
- wherein the side of the second conductivity-type III nitride semiconductor layer opposite to the support is the (000-1) side, and
- the III nitride semiconductor device has a plurality of protrusions rounded like domes in a predetermined region on the (000-1) side of the second conductivity-type III nitride semiconductor layer and has an electrode on the upper surface of the predetermined region, a surface of the plurality of protrusions comprising planes except for the (000-1) plane, and a height of the protrusions being 0.1 μm to 3 μm.
A method of producing a III nitride semiconductor device having a III nitride semiconductor layer, comprising the steps of:
- performing anisotropic etching on a predetermined region on the (000-1) side of the III nitride semiconductor layer to form a plurality of pyramidal projections;
- performing isotropic etching on the predetermined region to change the projections into protrusions rounded like domes, a surface of the protrusions comprising planes except for the (000-1) plane;
- and
- forming an electrode on the upper surface of the predetermined region having the protrusions.
A method of producing a III nitride semiconductor device, comprising the steps of:
- forming a lift-off layer, a second conductivity-type III nitride semiconductor layer, an active layer, and a first conductivity-type III nitride semiconductor layer in this order on a growth substrate;
- forming a support on the first conductivity-type III nitride semiconductor layer;
- removing the lift-off layer, thereby separating the growth substrate from the second conductivity-type III nitride semiconductor layer;
- performing anisotropic etching on a predetermined region of the exposed second conductivity-type III nitride semiconductor layer on the (000-1) plane side, thereby forming a plurality of pyramidal projections;
- performing isotropic etching on the predetermined region and changing the projections into a plurality of protrusions rounded like domes, a surface of the plurality of protrusions comprising planes except for the (000-1) plane;
- and
- forming an electrode on the upper surface of the predetermined region having the protrusions.
Dependencies are inferred from the claim text.