Semiconductor integrated circuit device
AssigneeRenesas Electronics Corporation
InventorsKazuo Tomita, Takeshi Kawamura
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Abstract
Provided is a semiconductor integrated circuit device having pixel regions in a photodiode array region and having, in each of the pixel regions, a waveguide holding hole having a substantially perpendicular sidewall above the photodiode and embedded with a silicon oxide-based sidewall insulating film reaching the bottom surface of the hole and two or more silicon nitride-based insulating films having a higher refractive index on the inner side of the hole. This structure makes it possible to prevent deterioration of pixel characteristics of an imaging device, such as CMOS sensor, which is rapidly decreasing in size.
Claims7
A semiconductor integrated circuit device including a CMOS image sensor, comprising:
- a photodiode formed in a semiconductor substrate and configuring a part of the CMOS image sensor;
- an interlayer insulating film formed over the photodiode;
- a waveguide holding hole formed in the interlayer insulating film above the photodiode;
- a first silicon nitride-based insulating film formed over a side surface and a bottom surface of the waveguide holding hole;
- a second silicon nitride-based insulating film formed over the first silicon nitride-based insulating film;
- and
- a third silicon nitride-based insulating film formed over the second silicon nitride-based insulating film,
- wherein the waveguide holding hole is embedded by the first, second and third silicon nitride-based insulating films,
- wherein the second silicon nitride-based insulating film has a refractive index higher than that of the first silicon nitride-based insulating film, and
- wherein the third silicon nitride-based insulating film has a refractive index higher than that of the second silicon nitride-based insulating film.
Dependencies are inferred from the claim text.