IMAGE SENSOR WITH DOPED TRANSFER GATE

摘要

An image sensor is fabricated by forming transfer gates over a substrate layer. A transfer gate is disposed between a respective shared charge-to-voltage conversion region and a photodetector associated with the shared charge-to-voltage conversion region. The transfer gates of each shared charge-to-voltage conversion region are spaced apart to form a conversion region gap. A masking conformal dielectric layer is deposited over the image sensor, covers the transfer gates, fills each conversion region gap, and is etched to form sidewall spacers along an outside edge of each transfer gate with a portion remaining in each conversion region gap and disposed over the substrate layer in each conversion region gap. Source/drain regions are implanted in the substrate layer where an implant region is formed in the transfer gates. The masking conformal dielectric layer in each conversion gap masks the source/drain implant Each charge-to-voltage conversion region is substantially devoid of the implant region.