Group III nitride compound semiconductor device and method of producing the same

A group III nitride compound semiconductor device, comprising:

• a substrate;
• a first group III nitride compound semiconductor layer having a thickness of from 50 Å to 3000 Å and being formed on said substrate by a method not using metal organic compounds as raw materials;
• and
• a second group III nitride compound semiconductor layer being formed on said first group III nitride compound layer,
• wherein said second group III nitride compound semiconductor layer is formed by a metal organic chemical vapor deposition method, and
• wherein said first group III nitride compound semiconductor layer is subjected to a heat treatment in a range of 1050° C. to 1200° C. before said second group III nitride compound semiconductor layer is formed thereon.

A group III nitride compound semiconductor device, comprising:

• a sapphire substrate;
• a first group III nitride compound semiconductor layer having a thickness of from 50 Å to 3000 Å and being formed on said sapphire substrate by a sputtering method;
• and
• a second group III nitride compound semiconductor layer formed on said first group III nitride compound semiconductor layer by a metal organic chemical vapor deposition method,
• wherein said first group III nitride compound semiconductor layer is subjected to a heat treatment in a range of 1050° C. to 1200° C. before said second group III nitride compound semiconductor layer is formed thereon.

A group III nitride compound semiconductor device, comprising:

• a buffer layer comprising a first group III nitride compound semiconductor layer;
• and
• a second group III nitride compound semiconductor layer formed on said buffer layer;
• wherein said buffer layer is formed on a substrate having a temperature not less than 400° C. by a method not using metal organic compounds as raw materials and is heated in an atmosphere of a mixture of gases containing hydrogen or nitrogen gas and ammonia gas before formation of said second group III nitride compound semiconductor layer, and
• wherein said first group III nitride compound semiconductor layer is subjected to a heat treatment in a range of 1050° C. to 1200° C. before said second group III nitride compound semiconductor layer is formed thereon.

A group III nitride compound semiconductor device, comprising:

• a first layer comprising a group III nitride compound semiconductor having a thickness of from 50Å to 3000Å and formed on a substrate having a temperature not less than 400° C.;
• and
• a second layer comprising a group III nitride compound semiconductor formed on said first layer, and having a crystallinity characterized b an x-ray rocking curve having a full width at half maximum (FWHM) of less than about 25 seconds,
• wherein said first layer is subjected to a heat treatment in a range of 1050° C. to 1200° C. before said second layer is formed thereon.