High quality CVD deposition of Ge layers for Ge/SiGe Quantum Well heterostructures

Fuente: arXiv
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Main Authors: Nigro, Arianna, Jutzi, Eric, Forrer, Nicolas, Hofmann, Andrea, Gadea, Gerard, Zardo, Ilaria
Format: Preprint
Published: 2024
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_version_ 1866916894387208192
author Nigro, Arianna
Jutzi, Eric
Forrer, Nicolas
Hofmann, Andrea
Gadea, Gerard
Zardo, Ilaria
author_facet Nigro, Arianna
Jutzi, Eric
Forrer, Nicolas
Hofmann, Andrea
Gadea, Gerard
Zardo, Ilaria
contents A great deal of interest is directed nowadays towards the development of innovative technologies in the field of quantum information and quantum computing, with emphasis on obtaining reliable qubits as building blocks. The realization of highly stable, controllable and accessible hole spin qubits is strongly dependent on the quality of the materials hosting them. Ultra-clean germanium/silicon-germanium heterostructures have been predicted and proven to be promising candidates and due to their large scalability potential, they are opening the door towards the development of realistic and reliable solid state, all-electric, silicon-based quantum computers. In order to obtain ultra-clean germanium/silicon-germanium heterostructures in a reverse grading approach, the understanding and control over the growth of Ge virtual substrates and thin films is key. Here, we present a detailed study on the growth kinetics, morphology, and crystal quality of Ge thin films grown via chemical vapor deposition by investigating the effects of growth temperature, partial pressure of the precursor gas and the use of Ar or H2 atmosphere. The presence of carrier gases catalyzes the deposition rate and induces a smoothening on the surfaces of films grown at low temperatures. We investigated the surface roughness and threading dislocation density as a function of deposition temperature, partial pressure and gas mixture. Ge thin films deposited by diluting GeH4 in Ar or H2 were employed as virtual substrates for the growth of full Ge/SiGe QW heterostructures. Their defect density was analyzed and their electric transport properties were characterized via Hall measurements. Similar results were obtained for both carrier gases used.
format Preprint
id arxiv_https___arxiv_org_abs_2405_08214
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle High quality CVD deposition of Ge layers for Ge/SiGe Quantum Well heterostructures
Nigro, Arianna
Jutzi, Eric
Forrer, Nicolas
Hofmann, Andrea
Gadea, Gerard
Zardo, Ilaria
Materials Science
A great deal of interest is directed nowadays towards the development of innovative technologies in the field of quantum information and quantum computing, with emphasis on obtaining reliable qubits as building blocks. The realization of highly stable, controllable and accessible hole spin qubits is strongly dependent on the quality of the materials hosting them. Ultra-clean germanium/silicon-germanium heterostructures have been predicted and proven to be promising candidates and due to their large scalability potential, they are opening the door towards the development of realistic and reliable solid state, all-electric, silicon-based quantum computers. In order to obtain ultra-clean germanium/silicon-germanium heterostructures in a reverse grading approach, the understanding and control over the growth of Ge virtual substrates and thin films is key. Here, we present a detailed study on the growth kinetics, morphology, and crystal quality of Ge thin films grown via chemical vapor deposition by investigating the effects of growth temperature, partial pressure of the precursor gas and the use of Ar or H2 atmosphere. The presence of carrier gases catalyzes the deposition rate and induces a smoothening on the surfaces of films grown at low temperatures. We investigated the surface roughness and threading dislocation density as a function of deposition temperature, partial pressure and gas mixture. Ge thin films deposited by diluting GeH4 in Ar or H2 were employed as virtual substrates for the growth of full Ge/SiGe QW heterostructures. Their defect density was analyzed and their electric transport properties were characterized via Hall measurements. Similar results were obtained for both carrier gases used.
title High quality CVD deposition of Ge layers for Ge/SiGe Quantum Well heterostructures
topic Materials Science
url https://arxiv.org/abs/2405.08214