Image sensor including transmitting layers having low refractive index

An image sensor comprising:

• a substrate;
• image pixels formed in the substrate to detect incident light into to provide optical image information and comprising:
• image photodiodes formed in the substrate;
• color filters formed over the substrate and vertically overlapping with the image photodiodes to transmit light of certain selected colors to corresponding image photodiodes, respectively;
• and
• image micro lenses over the color filters, and
• phase difference detection pixels formed in the substrate and located differently from the image pixels to detect light provide phase differences information for the optical image information provided by the image pixels and comprising:
• phase difference detection photodiodes formed in the substrate;
• a transmitting layers formed over the substrate to allow optical transmission of light and patterned to vertically overlap with the phase difference detection photodiodes, respectively;
• guide patterns formed between the substrate and the transmitting layers and structured to be optically opaque to block light incident to the guide patterns;
• and
• phase difference detection micro lenses formed over the transmitting layers to direct incident light to the phase difference detection photodiodes, respectively,
• wherein the transmitting layers have a refractive index lower than those of the color filters and the phase difference detection micro lenses.