Regensburg 2010 – scientific programme

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O: Fachverband Oberflächenphysik

O 69: Symposium Polarization Field Control in Group-III-Nitrides

O 69.1: Invited Talk

Thursday, March 25, 2010, 09:30–10:00, H1

Growth and applications of N-polar (Al,Ga,In)N — •Stacia Keller and Umesh K Mishra — Electrical and Computer Engineering Department, Univerisity of California, Santa Barbara, CA 93106, USA

While the properties of Ga-polar (Al,In,Ga)N/GaN structures have been widely studied in the past, N-polar nitride films were much less investigated, largely related to difficulties in the growth of smooth N-polar films, in particular by metal organic chemical vapor deposition. Due to the hexagonal symmetry of the GaN crystal, the properties of (Al,Ga,In)N heterostructures grown in both directions are strongly influenced by polarization effects, resulting in strong electric fields in the crystal. The opposite direction of the electric fields in N-polar in comparison to Ga-polar heterostructures is interesting in particular for applications such as enhancement mode transistors, and highly scaled transistors, photodetectors, and solar cells. After a discussion of growth and materials properties of N-polar (Al,Ga,In)N, special emphasis will be given to the fabrication and properties of N-polar GaN/AlGaN and GaN/AlInN transistors. Differences in the properties of N- and Ga-polar two dimensional electron gasses will be addressed as well.