A complementary metal-oxide-semiconductor image sensor may include: a semiconductor substrate; a photodiode formed on a first portion of the semiconductor substrate; a transfer gate formed on the semiconductor substrate, near the photodiode, to transfer optical charges accumulated in the photodiode; a floating diffusion area formed on a second portion of the semiconductor substrate, on an opposite side of the transfer gate from the photodiode, to accommodate the optical charges; and/or a channel area formed under the transfer gate and contacting a side of the photodiode to transfer the optical charges. The transfer gate may be formed, at least in part, of transparent material. A method of manufacturing a complimentary metal-oxide-semiconductor image sensor may include: forming the photodiode; forming the floating diffusion area, separate from the photodiode; and/or forming the transfer gate, near the photodiode, to transfer optical charges accumulated in the photodiode.