Through-silicon-trench in back-side-illuminated CMOS image sensors for the improvement of gate oxide long term performance

To improve the gate oxide long term performance of MOSFETs in back side illuminated CMOS image sensors the wafer back is patterned with suitable through-silicon-trenches. We demonstrate that the reliability improvement is due to the annealing of the gate oxide border traps thanks to passivating chemical species carried by trenches.