Year: 2024
Type: article
Abstract: Semiconductor nanowires (NWs) are believed to play a crucial role for future applications in electronics, spintronics and quantum technologies. A potential candidate is HgTe but its sensitivity to nanofabrication processes restrain its development. A way to circumvent this obstacle is the selective area growth technique. Here, in-plane HgTe nanostructures are grown thanks to selective area molecular beam epitaxy on a semi-insulating CdTe substrate covered with a patterned SiO2 mask. The shape of these nanostructures is defined by the in-plane orientation of the mask aperture along the <110>, <1 1 ¯ 0>, or <100> direction, the deposited thickness, and the growth temperature (GT). Several micron long in-plane NWs can be achieved as well as more complex nanostructures such as networks, diamond structures or rings. A good selectivity is achieved with very little parasitic growth on the mask even for a GT as low as 140 °C and growth rate up to 0.5 monolayer per second. For <110> oriented NWs, the center of the nanostructure exhibits a trapezoidal shape with {111}B facets and two grains on the sides, while <1 1 ¯ 0> oriented NWs show {111}A facets with adatoms accumulation on the sides of the top surface. Transmission electron microscopy observations reveal a continuous epitaxial relation between the CdTe substrate and the HgTe NW. Measurements of the resistance with four-point scanning tunneling microscopy indicates a good electrical homogeneity along the main NW axis and a thermally activated transport. This growth method paves the way toward the fabrication of complex HgTe-based nanostructures for electronic transport measurements.
Source: Nanotechnology
Authors: N Chaize, X Baudry, P-H Jouneau, E Gautier, J-L Rouvière, Y Deblock, J Xu, M Berthe, C Barbot, B Grandidier, L Desplanque, H Sellier, P Ballet
Institutions: Commissariat à l'Énergie Atomique et aux Énergies Alternatives, CEA Grenoble, Laboratoire d'Électronique des Technologies de l'Information, Université Grenoble Alpes, Institut Nanosciences et Cryogénie, Centre National de la Recherche Scientifique, Université de Lille, Renatech, Institut d'Electronique, de Microélectronique et de Nanotechnologie, Centrale Lille Institut, Brown University, Institut Néel
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Funder: Agence Nationale de la Recherche
OpenAlex ID: W4402883882