Investigation of resistance formation mechanisms for contacts to n-AlN and n-GaN with a high dislocation density

Autor: Sachenko, A.V., Belyaev, A.E., Boltovets, N.S., Zhilyaev, Yu.V., Kapitanchuk, L.M., Klad’ko, V.P., Konakova, R.V., Kudryk, Ya.Ya., Kuchuk, A.V., Naumov, A.V., Panteleev, V.V., Sheremet, V.N.
Jazyk: angličtina
Rok vydání: 2012
Popis: We studied temperature dependences of the resistivity, Pc(T) , of Pd-Ti-Pd-Au ohmic contacts to wide-gap semiconductors n - GaN and n - AlN with a high dislocation density. BothPc(T) curves have portions of exponential decrease, as well as those with very slight Pc(T) dependence at higher temperatures. Besides, the Au-Pd-TiPd-n-GaN contacts have a portion of Pc(T) flattening out in the low-temperature region. This portion appears only after rapid thermal annealing (RTA). In principle, its appearance may be caused by preliminary heavy doping of the near-contact region with a shallow donor impurity as well as doping in the course of contact formation owing to RTA, if the contact-forming layer involves a material atoms of which serve as shallow donors in III  N compounds. The obtained Pc(T) dependences cannot be explained by the existing mechanisms of current transfer. We propose other mechanisms explaining the experimental Pc(T) curves for ohmic contacts to n - GaN and n -AlN .
Databáze: OpenAIRE