Manufracturing method of solid-state imaging device
View Patent ↗A solid-state imaging device includes: a photoelectric conversion portion that receives an incident light from a back surface side of a silicon layer to perform photoelectric conversion on the incident light; and a pixel transistor portion that outputs signal charges generated in the photoelectric conversion portion towards a front surface side of the silicon layer, wherein a gettering layer having internal stress is provided on the front surface side of the silicon layer at a position to overlap the photoelectric conversion portion on a plan view layout thereof.
1. A manufacturing method of a solid-state imaging device comprising the steps of:
forming in a silicon layer, a photoelectric conversion portion that receives an incident light and performs photoelectric conversion on the incident light, a pixel transistor portion that outputs signal charges generated in the photoelectric conversion portion, and a peripheral circuit portion that is formed on the periphery of a pixel portion having the photoelectric conversion portion and the pixel transistor portion; and
the following previous steps including,
forming a first insulating film on the front surface of the silicon layer;
forming an aperture portion exposing the silicon layer at a position to overlap a region of the first insulating film, in which the photoelectric conversion portion is formed;
forming a gettering formation layer having internal stress on the first insulating film including an inside of the aperture portion;
forming device separation grooves in the silicon layer so as to separate the photoelectric conversion portion, the pixel transistor portion, and the peripheral circuit portion, and then forming a second insulating film on the gettering layer so as to bury the device separation grooves;
removing the second insulating film left on the gettering layer, thus forming device separation regions with the second insulating film remaining inside the device separation grooves; and
performing patterning so that the gettering formation layer remains inside the aperture portion, thus forming a gettering layer.