%0 Journal Article
%A Rieger, Torsten
%A Jörres, Torsten
%A Vogel, J.
%A Biermanns, A.
%A Pietsch, U.
%A Grützmacher, Detlev
%A Lepsa, Mihail Ion
%T Crystallization of $HfO_2$ in $InAs/HfO_2$ core–shell nanowires
%J Nanotechnology
%V 25
%N 40
%@ 1361-6528
%C Bristol
%I IOP Publ.
%M FZJ-2014-04991
%P 405701
%D 2014
%X We report the impact of deposition parameters on the structure of HfO2 covering InAs nanowires (NWs) being potential candidates for future field-effect transistors (FETs). Molecular beam epitaxial-grown Au-free InAs NWs were covered with HfO2 deposited by atomic-layer deposition. The impact of the film thickness as well as the deposition temperature on the occurrence and amount of crystalline HfO2 regions was investigated by high-resolution transmission electron microscopy (TEM) and x-ray diffraction. Compared to the deposition on planar Si substrates, the formation probability of crystalline HfO2 on InAs NWs is significantly enhanced. Here, even 3 nm thick films deposited at 250 °C are partly crystalline. Similarly, a low deposition temperature of 125 °C does not result in completely amorphous 10 nm thick HfO2 films, they contain monoclinic as well as orthorhombic HfO2 nanocrystals. Combining HfO2 and Al2O3 into a laminate structure is capable of suppressing the formation of crystalline HfO2 grains.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000342503800007
%R 10.1088/0957-4484/25/40/405701
%U https://juser.fz-juelich.de/record/156128