Method of fabricating seminconductor devices including self aligned refractory contacts

A method of forming a Group III-nitride semiconductor device, the method comprising:

• providing a semiconductor layer;
• selectively implanting ions into the semiconductor layer to provide highly doped implanted regions in the semiconductor layer;
• forming a refractory metal layer on the highly doped implanted regions in the semiconductor layer, wherein the highly doped implanted regions and refractory metal layer are both formed using a single mask;
• and
• annealing the highly doped implanted regions and the refractory metal layer in a single step to respectively activate the implanted ions of the highly doped implanted regions and form ohmic contacts that are self-aligned to the implanted regions on the implanted regions,
• wherein providing the semiconductor layer comprises:
• forming a channel layer on the semiconductor substrate;
• forming a barrier layer on the channel layer;
• and
• forming a protective layer on the barrier layer.

A method of forming a semiconductor device, the method comprising:

• providing a semiconductor layer;
• providing a protective layer on the semiconductor layer;
• providing a single mask on the protective layer;
• etching the protective layer according to the mask;
• implanting ions having a first conductivity type into the semiconductor layer according to the mask to form implanted regions on the semiconductor layer;
• and
• providing metal layers on the implanted regions according to the mask.