| CPC H01L 29/66431 (2013.01) [H01L 21/3245 (2013.01); H01L 21/76841 (2013.01); H01L 29/2003 (2013.01); H01L 29/7786 (2013.01)] | 18 Claims |

|
1. A high electron mobility transistor, comprising:
a channel layer disposed on a substrate;
a barrier layer disposed on the channel layer;
a passivation layer disposed on the barrier layer; and
a contact structure disposed on the passivation layer and extending through the passivation layer and the barrier layer to directly contact the channel layer, wherein the contact structure comprises:
a liner; and
a metal layer directly disposed on the liner, wherein the metal layer comprises a metal material doped throughout with a first additive and a second additive, and a weight percentage of the first additive in the metal layer is between 0% and 2%, a weight percentage of the second additive in the metal layer is between 0% and 1%.
|