Patent ID: 6395576
Filing Date: 2002-05-28
Classification: H01L

Abstract:
A real-time adaptive, ordered microelectronic fabrication process for adjusting color sensitivity balance during formation of integrated primary color filters in semiconductor array imagers, comprising the steps of:providing a semiconductor substrate having a matrix of photodiode elements formed thereon; depositing a passivation coating encapsulating a metal photoshield layer, wherein the metal photoshield elements are periodically spaced to cover the areas between the photodiode elements; forming upon the patterned and encapsulated metal photoshield layer a first optically transparent planarizing encapsulant layer; forming upon the first optically transparent planarizing encapsulant layer a first patterned lowermost blue filter layer registered with the photodiode elements, and deposited to a thickness value adjusted by a real-time spectrophotometric algorithmic analyzer driving a feedback servo-control loop, operating during the deposition process step to provide analog filter precompensation to achieve a color balance gain-ratio set by the integrated circuit amplifiers of the imaging device; forming over the first patterned lowermost blue filter layer a second patterned red filter layer registered with the first patterned lowermost blue filter layer and the photodiode array elements, and, formed using the identical servo-control process described herein for the lowermost blue filter; forming over the second patterned red filter layer a third green filter layer registered to the red filter and the lowermost blue filter layers and the photodiode array elements, and, formed using the identical servo-control process described herein for the blue and red filters; and forming upon the patterned green filter layer a spacer layer registered to all filter layers and a first microlens layer in mutual registration with all the preceding optical filter layers and the photodiode array elements.