@article{MAKHILLJEAS201813115428,
    title = {Three-Dimensional CMOS Image Sensors Integrated with On-Chip
Infrared Filters and Color Filters},
    journal = {Journal of Engineering and Applied Sciences},
    volume = {13},
    number = {1},
    pages = {264-268},
    year = {2018},
    issn = {1816-949x},
    doi = {jeasci.2018.264.268},
    url = {https://makhillpublications.co/view-article.php?issn=1816-949x&doi=jeasci.2018.264.268},
    author = {Myung Bok and},
    keywords = {Image sensor,3D sensor,depth sensor,color filter,infrared filter,light transmittance},
    abstract = {Infrared (IR) and color filters were integrated on one-chip CMOS image sensors to implement
3-Dimensional (3D) image sensors which are capable of capturing color image and depth information
simultaneously. The combination of light filters applied for the 3D image sensor consists of an IR cut filter
mounted over the objective lens module and on-chip filters such as IR pass filters and color filters. The IR cut
filters were designed by the Essential Macleod program and fabricated by inorganic thin film deposition with
RF magnetron sputtering. On-chip IR pass filters and color filters were fabricated by photolithography. The IR
cut filter was formed by alternately stacking a SiO<sub>2</sub> layer and a TiO<sub>2</sub> layer to form multilayers with a total
thickness of about 1930 nm. The spectrum characteristic of the IR cut filter showed a transmittance more than
90% for light with a wavelength ranging from about 400 nm to about 850 nm and showed a transmittance less
than about 10% for light with a wavelength longer than about 900 nm. The spectrum characteristic of the IR
pass filter showed a transmittance more than about 90% for light with a wavelength longer than about 850 nm
and a low enough transmittance for visible light. The fabrication process of the filters is fairly CMOS
compatible. Thus, the IR cut filter and IR pass filter together with the color filter are considered to be
successfully applicable to the 3D image sensor. The 3D sensor adopting the new filters can be used for various
imaging device applications which require conventional color image and distance information to an object at
the same time.}
    }