Oxygen Defect Engineering in Czochralski Silicon for RF and Power Devices: Linking Between Mechanical Strength, Thermal-Donor-Driven Resistivity Drift, and Device Reliability

Czochralski (Cz) silicon inherently contains high interstitial oxygen (Oᵢ) introduced from the silica crucible. Oxygen is simultaneously beneficial - improving mechanical robustness and enabling intrinsic gettering via oxygen precipitation - and risky, because oxygen aggregation can generate electrically active oxygen-related thermal donors (TDs) and associated metastable centres. TD formation typically accelerates in the 350-550 °C "danger zone" (with a canonical maximum near ~450 °C), where Oᵢ clusters can act as donors and induce time-and history-dependent shifts in carrier concentration and resistivity. These effects are reliability-critical for RF substrates (e.g., high-resistivity silicon and RF-SOI), where reduced effective resistivity degrades substrate isolation, increases coupling and can destabilise linearity-relevant metrics, and for power devices, where oxygen-related defect evolution can couple to carrier lifetime, leakage and breakdown stability through recombination-active states and precipitate/interface effects. This article consolidates oxygen incorporation and defect evolution windows, TD families and kinetics (including peak-then-decay behaviour), deactivation and passivation routes (high-temperature annihilation, hydrogen interaction, and carbon inhibition), and a metrology stack spanning FTIR, resistivity/SRP, Hall/Van-der-Pauw, DLTS/Laplace-DLTS and PL/hyperspectral wafer mapping. We emphasise a manufacturable qualification workflowstandardised activation/deactivation tests with wafer-scale mapping-to co-optimise mechanical strength, resistivity stability and device lifetime for RF and power applications.