Imager with recessed color filter array and method of forming the same

Abstract

A recessed color filter array using patterned metal as an etch stop and a method of forming the same. In one embodiment, at least one metal etch stop is formed in a semiconductor dielectric layer at the same time as the formation of one or more layers of metal interconnect elements, thereby reducing the number of necessary process steps and reducing costs. The etch stop may be formed at any layer where other metal elements are present.

Description

technical field [0001] Several embodiments of an embodiment of the invention relate to semiconductor devices and methods of fabricating such devices. Background technique [0002] As imaging arrays are used in smaller and smaller applications, there is a need to reduce the stack height of the imaging arrays, necessitating the use of recessed arrays, i.e., the pixel array is recessed in the substrate to prevent the color filters and lens elements from Some cases extend beyond the desired upper limit of the stack. Forming a recessed array typically requires the use of etch stops to accurately form the array. [0003] Figure 1A and 1B A simplified partial cross-sectional view of a prior art imager 100 is shown with a conventional etch stop 105 formed therein. The imager 100 includes a substrate 101 supporting an array of pixels 102 and a dielectric layer 103 (e.g., an oxide) including a plurality of individual dielectric layers that support connections to associated circuit...

AI Technical Summary

Problems solved by technology

In addition to the extra processing step, conventional nitride etch stops have several other disadvantages, for example, preventing effective alloying, which can lead to annealing of defective transistors

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