Doping-selective etching of silicon for wafer thinning in the fabrication of backside-illuminated stacked CMOS image sensors
Backside thinning, using silicon doping-selective etching, for the preparation of backside illuminated (BSI) CMOS sensors. Tailored HNA chemistry (HF: HNO3: CH3COOH) is used to stop at a dedicated p+/p- silicon transition layer with high p+/p- selectivity, providing sub‑micron total thickness variation.
