CMOS image sensor for improving the amount of light incident a photodiode

A CMOS (complementary metal oxide semiconductor) image sensor comprising:

• a semiconductor substrate having device isolation regions and active regions;
• a device isolation layer formed on the device isolation regions of the semiconductor substrate;
• gate electrodes formed on the active regions;
• a plurality of photodiode regions formed at a predetermined interval in the active regions and each photodiode region with at least one gate electrode of the gate electrodes isolated by the device isolation layer;
• an interlayer insulating layer formed above an entire surface of the semiconductor substrate;
• a refracting layer passing through the interlayer insulating layer and formed directly on portions of the device isolation layer, wherein the interlayer insulating layer and the refracting layer perform as a waveguide, wherein the refracting layer has a greater refractive index than the interlayer insulating layer;
• a planarizing layer formed on an entire surface of the semiconductor substrate including the refracting layer;
• a color filter layer formed on the planarizing layer and including a plurality of color segments corresponding respectively to the photodiode regions;
• and
• a microlens formed respectively on each color segment of the color filter layer,
• wherein the planarizing layer includes a level upper surface and is disposed between the color filter layer and the refracting layer,
• wherein the refracting layer is directly contacted with the planarizing layer and is disposed below the color filter layer at a region corresponding to a boundary of each color segment.