The optimal regime of trap reach—high resistivity (TR-HR) layer formation—was developed by the CO+ ion implantation (E = 90–200 keV, F = (0.3–3.0) × 1016 cm–2) and subsequent furnace or rapid thermal annealings (FA or RTA). The TR-HR zones in Si substrates can be placed under microwave or photon radiation in silicon-on-insulator (SOI) radiophotonic integral circuits (RPIC) based on both standard SOI SiO2 buried oxide (BOX) up to 1 µm thick and on SOI wafers with a crystalline high-k BOX with an equivalent oxide thickness (EOT) ≥1 nm. The TR-HR layer during the stepwise RTA (sRTA) at 700 to 950°C reduced the BOX thickness and increased the effective EOT, but, at the same time, provided the highest decrease in the pass-through capacity Cp and an increase in the effective substrate resistance ρeff, similar to high-resistance TR-HR SOI® wafers.
Popov et al. (Mon,) studied this question.