Enrichment and growth of enriched $^{28}$Si films

In support of quantum information and spintronics efforts, we are producing enriched $^{28}$Si films that are 99.9{\%} $^{28}$Si according to secondary ion mass spectrometry assessment. We use an ionization source to crack and ionize natural abundance silane gas, then extract the ions through a magnetic sector analyzer to isolate the major isotope $^{28}$Si. We have presently demonstrated \textgreater\ 100 nm thick films of silicon and carbon, which was enriched to 99.996{\%} $^{12}$C. With ongoing improvements, we expect to produce $^{28}$Si enriched to better than 99.99{\%} at thicknesses \textgreater\ 1 $\mu $m grown epitaxially on Si(100) substrates.