Submicron spaced lens array process technology for a high photosensitivity CCD image sensor

Submicron-spaced lens array process technology has been developed for an IT-CCD (interline transfer charge coupled device) image sensor to realize high photosensitivity. The photosensitivity of a 0.8- mu m-spaced lens array has been increased to more than 2.5 times the sensitivity for the case of no lens, and an effective aperture ratio of 68% has been realized in a 1/3-inch optical format 512 (H)*492 (V) pixel IT-CCD image sensor. By means of a lens simulation, it was found that the rectangular dome-lens shows the highest sensitivity among lenses of various forms for a 1/3-inch IT-CCD image sensor. Experimental results for the rectangular dome-lenses are well explained by this simulation. The submicron-spaced lens array process has been established by adopting a new type of lens resin, an optimized lens design, and an excellent planarization process on the color filter layer.<
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