Transistor assembly and method for manufacturing the same

A transistor assembly comprising:

• a support substrate;
• and
• a transistor secured on the support substrate, wherein
• the transistor includes a first semiconductor layer and a second semiconductor layer having a greater bandgap than the first semiconductor layer, layered in this order on a principle surface of a base substrate,
• the base substrate is made of a material different from that of the first semiconductor layer and the second semiconductor layer, and
• a tensile stress is applied on the second semiconductor layer, and
• a value of a c-axis lattice constant of the first semiconductor layer is 99.9% or more and 100.1% or less of a theoretical value of a c-axis lattice constant of a material of the first semiconductor layer.

A transistor assembly comprising:

• a support substrate;
• and
• a transistor secured on the support substrate, wherein
• the transistor includes a first semiconductor layer and a second semiconductor layer having a greater bandgap than the first semiconductor layer, layered in this order on a principle surface of a base substrate,
• the base substrate is made of a material different from that of the first semiconductor layer and the second semiconductor layer,
• a tensile stress is applied on the second semiconductor layer, and
• a radius of curvature of the base substrate is greater than or equal to 12000 m.