Stark shift and field ionization of arsenic donors in ²⁸Si-silicon-on-insulator structures

We develop an efficient back gate for silicon-on-insulator (SOI) devices operating at cryogenic temperatures and measure the quadratic hyperfine Stark shift parameter of arsenic donors in isotopically purified ²⁸Si-SOI layers using such structures. The back gate is implemented using MeV ion implantation through the SOI layer forming a metallic electrode in the handle wafer, enabling large and uniform electric fields up to 2 V/μm to be applied across the SOI layer. Utilizing this structure, we measure the Stark shift parameters of arsenic donors embedded in the ²⁸Si-SOI layer and find a contact hyperfine Stark parameter of η_a = −1.9 ± 0.7 × 10⁻³ μm²/V². We also demonstrate electric-field driven dopant ionization in the SOI device layer, measured by electron spin resonance.