Patent ID: 8253170

Claim:
An electronic device successively comprising from its base to its surface: a) a support layer; b) a channel layer adapted to contain an electron gas; c) a barrier layer; and d) at least one ohmic contact electrode formed by a superposition of non alloyed metallic layers a first layer of which is in contact with the barrier layer, wherein the barrier layer includes a contact region disposed under the at least one ohmic contact electrode, further wherein the contact region includes at least one metal selected from the group of metals from which the ohmic contact electrode is formed, and further wherein the barrier layer and the channel layer each include at least one of a Group III material and nitrogen, and wherein the contact region includes at least one of aluminium, titanium, molybdenum, tungsten, ruthenium and tantalum, and further wherein the metals content of the contact region is between 10 19 and 10 21 atoms per cm 3 .