Abrupt Schottky Junctions in Al/Ge Nanowire Heterostructures

S. Kral (1) , C. Zeiner (1) , M. Stoeger-Pollach (1) , E. Bertagnolli (1) , Martien den Hertog (2) , M. Lopez-Haro (3) , Eric Robin (3) , Khalil El Hajraoui (2) , A. Lugstein (1)

1 TU Wien - Vienna University of Technology = Technische Universität Wien
2 NEEL - MRS - Matériaux, Rayonnements, Structure
3 LEMMA - Laboratoire d'Etude des Matériaux par Microscopie Avancée

In this Letter we report on the exploration of axial metal/semiconductor (Al/Ge) nanowire heterostructures with abrupt interfaces. The formation process is enabled by a thermal induced exchange reaction between the vapor-liquid-solid grown Ge nanowire and Al contact pads due to the substantially different diffusion behavior of Ge in Al and vice versa. Temperature-dependent I-V measurements revealed the metallic properties of the crystalline Al nanowire segments with a maximum current carrying capacity of about 0.8 MA/cm(2). Transmission electron microscopy (TEM) characterization has confirmed both the composition and crystalline nature of the pure Al nanowire segments. A very sharp interface between the (111) oriented Ge nanowire and the reacted Al part was observed with a Schottky barrier height of 361 meV. To demonstrate the potential of this approach, a monolithic Al/Ge/Al heterostructure Was used to fabricate a novel impact ionization device.

Mots clés: Heterostructure; Schottky Contact Aluminum; Impact; Ionization; Building-Blocks; Surface-States; Ge Nanowires; Electromigration; Transistors; Germanium; Contacts

Domaines: Physique [physics]

S. Kral, C. Zeiner, M. Stoeger-Pollach, E. Bertagnolli, Martien den Hertog, et al.. Abrupt Schottky Junctions in Al/Ge Nanowire Heterostructures. Nano Letters, 2015, 15 (7), pp.4783-4787. ⟨10.1021/acs.nanolett.5b01748⟩. ⟨hal-01615211⟩