Novel methods to reduce leakage current in Si PIN photodiodes designed and fabricated with different dielectrics

The silicon PIN photodiodes were designed and fabricated in the conventional bipolar planar technology by using novel methods to reduce the leakage current. The new process steps like gettering, oxide stacking fault removing, ion implantation with suitable masking and improving shallow junction technology were implemented to fabricate PIN photodiodes of different active area such as 1 mm × 1 mm, 2 mm × 2 mm and 10 mm × 10 mm. The performance of PIN photodiodes has been studied by measuring dark current, C-V characteristics and spectral response. The two different dielectrics such as silicon dioxide (SiO2) and silicon nitride (Si3N4) with different thickness were used as anti-reflective coating (ARC). The electrical characteristics and spectral measurements exhibit that the photodiodes are highly sensitive with low leakage current.