Electrode for p-type gallium nitride-based semiconductors

A method for producing a semiconductor device comprising:

• providing a substrate having a first major surface;
• providing a semiconductor device structure over the first major surface of the substrate, the device structure comprising an n-type gallium nitride-based semiconductor layer, and a p-type gallium nitride-based semiconductor layer over the n-type semiconductor layer;
• forming an electrode in electrical contact with the n-type gallium nitride-based semiconductor layer;
• forming three or more metallic layers over the p-type semiconductor layer, wherein at least one of the metallic layers is in contact with the p-type semiconductor layer;
• and
• subjecting at least two of the metallic layers to an annealing treatment in the presence of oxygen to form an electrode in contact with the p-type gallium nitride-based semiconductor layer.

An electrode for a p-type gallium nitride based semiconductor material, comprising:

• a) a layer of an oxidized metal having a first and a second surface;
• b) a layer of a first metallic material having a first surface in contact with the p-type gallium nitride based semiconductor material and a second surface in contact with the first surface of the oxidized metal layer;
• and
• c) a layer of a second metallic material having a surface in contact with the second surface of the oxidized metal layer.