Isolation techniques for reducing dark current in CMOS image sensors
AssigneeMicron Technology, Inc.
InventorsChandra Mouli, Howard Rhodes
Life of this patent
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Abstract
Isolation methods and devices for isolating regions of a semiconductor device. The isolation method and structure include forming an isolating trench in an active area and filling the trench with a doped conductive material containing silicon. Suitable conductive materials containing silicon include polysilicon and silicon-germanium. There is also provided a method and structure for isolating the regions by providing a trench in an active area of a substrate, growing an epitaxial layer in the trench to fill the trench or to partially fill the trench and depositing an insulating material over the epitaxial layer and within the trench to completely fill the trench.
Claims42
A structure for isolating areas in a semiconductor device, said structure comprising:
- a trench formed in a substrate between adjacent regions;
- a nitride liner lining at least one sidewall of said trench;
- an oxide liner over the nitride liner;
- an epitaxial layer in contact with said substrate at a bottom surface of said trench and filling at least a portion of said trench.
A structure for isolating areas in an image sensor, said structure comprising:
- a trench formed in an image sensor substrate between adjacent pixels;
- an insulating liner formed along at least one wall of said trench;
- an epitaxial layer in contact with said substrate at a bottom surface of said trench;
- and
- a filler material deposited over said epitaxial layer and within said trench, wherein said filler material comprises a conductive material.
A processing system comprising:
- (i) a processor;
- and (ii) a semiconductor device coupled to said processor and including:
- a trench formed in a substrate between adjacent regions;
- a nitride liner lining at least one sidewall of said trench;
- an oxide liner over the nitride liner;
- and
- an epitaxial layer in contact with said substrate at a bottom surface of said trench and filling at least a portion of said trench.
Dependencies are inferred from the claim text.