Isotopically Enriched Silicon, Germanium, and Their Hydrides for Quantum Computer Development

Abstract

In this paper, we report the preparation of high-purity ²⁸Si silicon and ⁷²Ge germanium isotopes and their volatile hydrides with controlled concentrations of the ²⁹Si and ⁷³Ge nonzero nuclear spin isotopes for producing Si/SiGe heterostructures for quantum computers employing the nuclear spin state as a qubit. We have prepared ²⁸SiH₄ and ²⁸Si samples containing about 99.9, 99.99, and 99.999% ²⁸Si as a major isotope and 340 ± 8, 41.1 ± 4.3, and 11.4 ± 0.1 ppm of the ²⁹Si isotope. In addition, we obtained high-purity ⁷²GeH₄ and ⁷²Ge samples containing about 99.9% ⁷²Ge as a major isotope and 109.9 ± 9.6 ppm of the ⁷³Ge isotope.