K Tang1, H S Kim2, A N R Ramanayaka2, D S Simons2, J M Pomeroy2. 1. Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20740, USA. 2. National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8423, USA.
Abstract
An ultrahigh vacuum (UHV) compatible Penning ion source for growing pure, highly enriched 28Si epitaxial thin films is presented. Enriched 28Si is a critical material for quantum information due to the elimination of nuclear spins. In some cases, the material must be grown by low temperature molecular beam epitaxy, e.g., scanning tunneling microscopy hydrogen lithography-based devices. Traditional high-purity physical vapor methods typically deliver a very small fraction of source material onto the target substrate, making the cost for use with highly enriched source materials very high. Thus, directed beam sources provide an efficient alternative. This UHV Penning source uses all metal or ceramic parts and a removable electromagnet to allow bake-out. The source gas is a commercial (natural isotope abundance) silane gas (SiH4), an inexpensive source material. High enrichment levels up to 99.999 87% (8.32 × 10-7 mol/mol 29Si) and high chemical purity of 99.965% are shown without postprocessing. We present and discuss the discharge properties of this new source, the ion mass spectrum when coupled to our mass filter, and the secondary ion mass spectroscopy of the grown films.
An ultrahigh vacuum (UHV) compatible Penning ion source n class="Chemical">for growing pure, highly enriched 28Si epitaxial thin films is presented. Enriched 28Si is a critical material for quantum information due to the elimination of nuclear spins. In some cases, the material must be grown by low temperature molecular beam epitaxy, e.g., scanning tunneling microscopy hydrogen lithography-based devices. Traditional high-purity physical vapor methods typically deliver a very small fraction of source material onto the target substrate, making the cost for use with highly enriched source materials very high. Thus, directed beam sources provide an efficient alternative. This UHV Penning source uses all metal or ceramic parts and a removable electromagnet to allow bake-out. The source gas is a commercial (natural isotope abundance) silane gas (SiH4), an inexpensive source material. High enrichment levels up to 99.999 87% (8.32 × 10-7 mol/mol 29Si) and high chemical purity of 99.965% are shown without postprocessing. We present and discuss the discharge properties of this new source, the ion mass spectrum when coupled to our massfilter, and the secondary ion mass spectroscopy of the grown films.
Authors: M Veldhorst; C H Yang; J C C Hwang; W Huang; J P Dehollain; J T Muhonen; S Simmons; A Laucht; F E Hudson; K M Itoh; A Morello; A S Dzurak Journal: Nature Date: 2015-10-05 Impact factor: 49.962
Authors: Kamyar Saeedi; Stephanie Simmons; Jeff Z Salvail; Phillip Dluhy; Helge Riemann; Nikolai V Abrosimov; Peter Becker; Hans-Joachim Pohl; John J L Morton; Mike L W Thewalt Journal: Science Date: 2013-11-15 Impact factor: 47.728
Authors: M Veldhorst; J C C Hwang; C H Yang; A W Leenstra; B de Ronde; J P Dehollain; J T Muhonen; F E Hudson; K M Itoh; A Morello; A S Dzurak Journal: Nat Nanotechnol Date: 2014-10-12 Impact factor: 39.213
Authors: Alexei M Tyryshkin; Shinichi Tojo; John J L Morton; Helge Riemann; Nikolai V Abrosimov; Peter Becker; Hans-Joachim Pohl; Thomas Schenkel; Michael L W Thewalt; Kohei M Itoh; S A Lyon Journal: Nat Mater Date: 2011-12-04 Impact factor: 43.841
Authors: Juha T Muhonen; Juan P Dehollain; Arne Laucht; Fay E Hudson; Rachpon Kalra; Takeharu Sekiguchi; Kohei M Itoh; David N Jamieson; Jeffrey C McCallum; Andrew S Dzurak; Andrea Morello Journal: Nat Nanotechnol Date: 2014-10-12 Impact factor: 39.213