Method for manufacturing nitride semiconductor crystal layer

A method for manufacturing a nitride semiconductor crystal layer comprising:

• forming the nitride semiconductor crystal layer having a first thickness on a silicon crystal layer, the silicon crystal layer being provided on a base body, the base body includes a silicon substrate and a silicon oxide film formed on the silicon substrate,
• the silicon crystal layer having a second thickness before the forming the nitride semiconductor crystal layer, the second thickness being thinner than the first thickness,
• the forming the nitride semiconductor crystal layer including making at least a portion of the silicon crystal layer incorporated into the nitride semiconductor crystal layer to reduce a thickness of the silicon crystal layer from the second thickness,
• wherein the forming the nitride semiconductor crystal layer includes,
• forming a first portion of the nitride semiconductor crystal layer on the silicon crystal layer at a first temperature, and
• forming a second portion of the nitride semiconductor crystal layer on the first portion at a second temperature, the second temperature being higher than the first temperature;
• and
• wherein the forming the nitride semiconductor crystal layer includes,
• making the silicon crystal layer incorporated into the nitride semiconductor crystal layer to cause disappearance of the silicon crystal layer, and
• forming a structure including
• the silicon substrate,
• the silicon oxide film formed on the silicon substrate, and
• the nitride semiconductor crystal layer provided on the silicon oxide film, and silicon included in the silicon crystal layer is introduced in the nitride semiconductor crystal layer.