US 10,256,335 B2 · Nitride semiconductor device and fabrication method therefor

Abstract

A nitride semiconductor device includes an electron transit layer (103) that is formed of a nitride semiconductor, an electron supply layer (104) that is formed on the electron transit layer (103), that is formed of a nitride semiconductor whose composition is different from the electron transit layer (103) and that has a recess (109) which reaches the electron transit layer (103) from a surface, a thermal oxide film (111) that is formed on the surface of the electron transit layer (103) exposed within the recess (109), a gate insulating film (110) that is embedded within the recess (109) so as to be in contact with the thermal oxide film (111), a gate electrode (108) that is formed on the gate insulating film (110) and that is opposite to the electron transit layer (103) across the thermal oxide film (111) and the gate insulating film (110), and a source electrode (106) and a drain electrode (107) that are provided on the electron supply layer (104) at an interval such that the gate electrode (108) intervenes therebetween.

Claims32

Dependent claims

A nitride semiconductor device comprising:

a substrate;
an electron transit layer that is formed on the substrate, and that is formed of a nitride semiconductor;
an electron supply layer that is formed on the electron transit layer, and that is formed of a nitride semiconductor whose composition is different from the electron transit layer;
an AlGaN buffer layer that intervenes between the substrate and the electron transit layer, and that includes a high aluminum composition region whose aluminum composition is relatively high and a low aluminum composition region whose aluminum composition is lower than the high aluminum composition region and which is arranged in a region close to the electron transit layer as compared with the high aluminum composition region;
and
an element separation layer that is formed with a region whose resistance is increased by causing a crystal defect through ion implantation, and that passes through the electron supply layer, the electron transit layer, and the low aluminum composition region to reach the high aluminum composition region, a bottom portion of the element separation layer being located within the high aluminum composition region.

3 more elements

A method of manufacturing a nitride semiconductor device, the method comprising:

a step of forming an AlGaN buffer layer by epitaxially growing an AlGaN crystal on a substrate such that an aluminum composition is relatively high in a high aluminum composition region close to the substrate and the aluminum composition is relatively low in a low aluminum composition region away from the substrate;
a step of forming an electron transit layer by epitaxially growing a nitride semiconductor on the AlGaN buffer layer;
a step of forming an electron supply layer on the electron transit layer by epitaxially growing a nitride semiconductor layer whose composition is different from the electron transit layer;
and
a step of forming a high resistance element separation layer that passes through the electron supply layer, the electron transit layer, and the low aluminum composition region to reach the high aluminum composition region by breaking a crystal structure through ion implantation on the electron supply layer, the electron transit layer, and the high aluminum composition region, wherein a bottom portion of the high resistance element separation layer is located within the high aluminum composition region.

2 more elements

Dependencies are inferred from the claim text.

Nitride semiconductor device and fabrication method therefor

Life of this patent

Nitride semiconductor device and fabrication method therefor

Life of this patent

Abstract

Claims32