Journal Article

FZJ-2015-03356

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Controlling the interface charge density in GaN-based metal-oxide-semiconductor heterostructures by plasma oxidation of metal layers

Hahn, H. (Corresponding Author) ; Pécz, B. ; Kovács, A.FZJ* ; Heuken, M. ; Kalisch, H. ; Vescan, A.

2015
American Inst. of Physics Melville, NY

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Please use a persistent id in citations: http://hdl.handle.net/2128/17107  doi:10.1063/1.4921867

Abstract: In recent years, investigating and engineering the oxide-semiconductor interface in GaN-based devices has come into focus. This has been driven by a large effort to increase the gate robustness and to obtain enhancement mode transistors. Since it has been shown that deep interface states act as fixed interface charge in the typical transistor operating regime, it appears desirable to intentionally incorporate negative interface charge, and thus, to allow for a positive shift in threshold voltage of transistors to realise enhancement mode behaviour. A rather new approach to obtain such negative charge is the plasma-oxidation of thin metal layers. In this study, we present transmission electron microscopy and energy dispersive X-ray spectroscopy analysis as well as electrical data for Al-, Ti-, and Zr-based thin oxide films on a GaN-based heterostructure. It is shown that the plasma-oxidised layers have a polycrystalline morphology. An interfacial amorphous oxide layer is only detectable in the case of Zr. In addition, all films exhibit net negative charge with varying densities. The Zr layer is providing a negative interface charge density of more than 1 × 1013 cm–2 allowing to considerably shift the threshold voltage to more positive values.

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Contributing Institute(s):

1. Mikrostrukturforschung (PGI-5)
2. JARA-FIT (JARA-FIT)

Research Program(s):

1. 143 - Controlling Configuration-Based Phenomena (POF3-143) (POF3-143)

Appears in the scientific report 2015

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Database coverage:
; ; Current Contents - Physical, Chemical and Earth Sciences ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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