Iii-nitride semiconductor growth substrate, iii-nitride semiconductor epitaxial substrate, iii-nitride semiconductor element, iii-nitride semiconductor freestanding substrate, and method for fabricating these

A method for fabricating a III-nitride semiconductor element, comprising the steps of:

• forming a single metallic layer made from Zr or Hf material on a crystal growth substrate, at least a surface portion of which substrate includes a III-nitride semiconductor containing Al;
• performing heat treatment on the single metallic layer under a hydrogen atmosphere to fabricate a III-nitride semiconductor growth substrate;
• epitaxially growing at least one III-nitride semiconductor layer over the III-nitride semiconductor growth substrate to fabricate a III-nitride semiconductor epitaxial substrate;
• performing a device isolation process on the least one III-nitride semiconductor layer;
• forming a support substrate at the side of the III-nitride semiconductor layer;
• and
• selectively etching the single metallic layer so that the III-nitride semiconductor layer is separated from the crystal growth substrate by chemical lift-off to obtain a III-nitride semiconductor element.

A method for fabricating a III-nitride semiconductor freestanding substrate, comprising the steps of:

• forming a single metallic layer made from Zr or Hf on a crystal growth substrate, at least a surface portion of which substrate includes a III-nitride semiconductor containing Al;
• performing heat treatment on the single metallic layer under a hydrogen atmosphere to fabricate a III-nitride semiconductor growth substrate;
• epitaxially growing at least one III-nitride semiconductor layer over the III-nitride semiconductor growth substrate;
• and
• selectively etching the single metallic layer so that the III-nitride semiconductor layer is separated from the crystal growth substrate by chemical lift-off to obtain a III-nitride semiconductor freestanding substrate.