Back side defect reduction for back side illuminated image sensor

摘要

Provided is an image sensor device. The image sensor device includes a substrate having a front side and a back side. The image sensor also includes a radiation-detection device that is formed in the substrate. The radiation-detection device is operable to detect a radiation wave that enters the substrate through the back side. The image sensor further includes a recrystallized silicon layer. The recrystallized silicon layer is formed on the back side of the substrate. The recrystallized silicon layer has different photoluminescence intensity than the substrate.

主权项

1. A method of fabricating an image sensor device, comprising:
providing a substrate having a first side and a second side, the substrate containing a silicon material; forming a radiation-sensitive element in the substrate, the radiation-sensitive element being configured to detect radiation that enters the substrate through the second side; thereafter thinning the substrate from the second side; implanting a dopant to the thinned substrate from the second side; and after the implanting, performing an annealing process to form recrystallized silicon in a first portion of the thinned substrate near the second side, wherein the annealing process comprises melting the silicon material in the first portion of the substrate and causing the melted silicon material to recrystallize, thereby forming the recrystallized silicon.