The HKD/AR1 AlO deposition step is a critical backside passivation process in backside-illuminated (BSI) CMOS image sensors P1.After the substrate thinning required for BSI architectures, the exposed backside silicon surface is highly prone to structural defects and dangling bonds, which act as severe generation-recombination centers P1.Following the preceding RF plasma step that cleans and conditions the surface P3, the aluminum oxide (Al2O3) layer is deposited to electrically passivate these s