Air Water Inc.

Mitsuhisa Narukawa

Keisuke Kawamura

Sumito Ouchi

Hiroki Suzuki

Akira Fukazawa

Hiroki Sukuki

A compound semiconductor substrate has a Si (silicon) substrate, a first Al nitride semiconductor layer which is a graded layer formed on the Si substrate and whose Al concentration decreases as the distance from the Si substrate increases along the thickness direction, a GaN (gallium nitride) layer formed on the first Al nitride semiconductor layer and having a lower average Al concentration than the average Al concentration of the first Al nitride semiconductor layer, and a second Al nitride semiconductor layer formed on the GaN layer and having a higher average Al concentration than the average Al concentration of the GaN layer. The threading dislocation density at any position in the thickness direction within the second Al nitride semiconductor layer is lower than the threading dislocation density at any position in the thickness direction within the first Al nitride semiconductor layer.

Compound semiconductor substrate including nitride semiconductor layer having varying threading dislocation densities

A method for manufacturing a compound semiconductor substrate comprises: a step to form an SiC (silicon carbide) layer on a Si (silicon) substrate, a step to form a LT (Low Temperature)-AlN (aluminum nitride) layer with a thickness of 12 nanometers or more and 100 nanometers or less on the SiC layer at 700 degrees Celsius or more and 1000 degrees Celsius or less, a step to form a HT (High Temperature)-AlN layer on the LT-AlN layer at a temperature higher than the temperature at which the LT-AlN layer was formed, a step to form an Al (aluminum) nitride semiconductor layer on the HT-AlN layer, a step to form a GaN (gallium nitride) layer on the Al nitride semiconductor layer, and a step to form an Al nitride semiconductor layer on the GaN layer.

Compound semiconductor substrate comprising a SiC layer

A compound semiconductor substrate includes a SiC (silicon carbide) layer, a AlN (aluminum nitride) buffer layer formed on the SiC layer, an Al (aluminum) nitride semiconductor layer formed on the AlN buffer layer, a composite layer formed on the Al nitride semiconductor layer, a GaN (gallium nitride) layer as an electron transition layer formed on the composite layer, and an Al nitride semiconductor layer as a barrier layer formed on the GaN layer. The composite layer includes C&#x2014;GaN layers stacked in a vertical direction, and an AlN layer formed between the C&#x2014;GaN layers.

Compound semiconductor substrate including electron transition layer and barrier layer

A compound semiconductor substrate having a desired quality is provided. A compound semiconductor substrate has an SiC (silicon carbide) layer, an AlN (aluminum nitride) buffer layer formed on the SiC layer, an Al (aluminum) nitride semiconductor layer formed on the AlN buffer layer, a first GaN (gallium nitride) layer formed on the Al nitride semiconductor layer, a first AlN intermediate layer formed on the first GaN layer in contact with the first GaN layer, and a second GaN layer formed on the first AlN intermediate layer in contact with the first AlN intermediate layer.

Compound semiconductor substrate with SiC layer

A composite semiconductor substrate being able to improve voltage withstanding and crystalline quality is provided. A composite semiconductor substrate is equipped with an Si (silicon) substrate, an SiC (silicon carbide) layer formed on the surface of the Si substrate, an AlN (aluminum nitride) layer formed on the surface of the SiC layer, a composite layer formed on the surface of the AlN layer, and a GaN (gallium nitride) layer formed on the surface of the composite layer. The composite layer includes an AlN (aluminum nitride) layer and a GaN layer formed on the surface of the AlN layer. In at least one composite layer, the average density of C and Fe in the GaN layer is higher than the average density of C and Fe in the AlN layer.

Growing community of inventors

Matsumoto, Japan

Mitsuhisa Narukawa