A prototype projection color display based on liquid-crystal-on-silicon cell was developed. Instead of being placed on glass plate, the color filters were deposited directly onto fine silicon pixels with compatible silicon manufacturing process. High precision of alignment between color filter and tiny silicon subpixel was achieved by this color-filter-on-chip approach. The alignment error of less than lpm between color filter and silicon subpixel was obtained. By fine tuning process parameter, high contrast ratio and color purity was achieved. Results on color coordinates for different processing parameters were reported. Color purity obtained was more than 88% for each primary color. The contrast ratio was more than 8:l under white light illumination. This color quality is comparable...[ Read more ]

A prototype projection color display based on liquid-crystal-on-silicon cell was developed. Instead of being placed on glass plate, the color filters were deposited directly onto fine silicon pixels with compatible silicon manufacturing process. High precision of alignment between color filter and tiny silicon subpixel was achieved by this color-filter-on-chip approach. The alignment error of less than lpm between color filter and silicon subpixel was obtained. By fine tuning process parameter, high contrast ratio and color purity was achieved. Results on color coordinates for different processing parameters were reported. Color purity obtained was more than 88% for each primary color. The contrast ratio was more than 8:l under white light illumination. This color quality is comparable to the NTSC standard for TV display. The major drawback of this technology is the excessive voltage drop across the color filter. To resolve the problem, color filter with larger dielectric constant or data driver with higher voltage driving capability has to be used. This color-filter-on-chip technology was developed for full-color silicon based active matrix liquid crystal display.