GROWTH OF Al(Ga)N/GaN HETEROEPITAXIAL TRANSISTOR STRUCTURES: FROM EPITAXYAL BUFFER LAYERS TO SURFACE PASSIVATION
T.V. Malin1, D.S. Milakhin1, V.G. Mansurov1, A.S. Kozhukhov1, D.Yu. Protasov1,2, I.D. Loshkarev1, K.S. Zhuravlev1
1Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk State Technical University, Novosibirsk, Russia
Keywords: коллапс тока, пассивация, GaN, NH3-MBE, Al(Ga)N/GaN-HEMT, current collapse, passivation
Abstract
The present study deals with the structurally perfect high-resistance GaN layer growth ability by the ammonia molecular beam epitaxy technique. The results allow forming SiN/Al (Ga)N/GaN heterostructures for transistors with high electron mobility. In this work, the conditions for growing GaN layers with a smooth surface morphology (RMS ~ 2 nm) suitable for creating sharp heterojunctions are determined, and a possibility of improving the GaN layer crystal perfection is demonstrated using a high-temperature (growth temperature more than 940 °С) buffer AlN layer. It is shown that in situ passivation of the Al(Ga)N/GaN heterostructure surface with an ultrathin SiN layer results in the formation of normally closed transistors with low competitive values of the current collapse (~ 1%).
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