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US 7,001,795 B2Granted
Total internal reflection (TIR) CMOS imager
AssigneeMicron Technology, Inc.
InventorsTongbi Jiang, Michael Connell, Jin Li
Life of this patent
Estimating the term…
Abstract
The subject invention is directed to use of photoconductors as conductors of light to photo diodes in a CMOS chip, wherein said photoconductors are separated by at least one low refractive index material (i.e. air). The present invention offers advantages over previous CMOS imaging technology, including enhanced light transmission to photo diodes. The instant methods for producing a CMOS imaging device and CMOS imager system involve minimal power loss. Since no lens is required, the invention eliminates concerns about radius limitation and about damaging lenses during die attach, backgrind, and mount. The invention also provides little or no cross talk between photo diodes.
Claims63
A method of fabricating a photoconductor array in a CMOS imaging device, comprising:
- forming a plurality of photo diodes;
- forming a sacrificial layer over said plurality of photo diodes;
- removing at least a portion of said sacrificial layer to expose an opening over each of said photo diodes;
- forming a photoconductor over each said photo diode and within said openings;
- and
- removing said sacrificial layer surrounding each said photoconductor, wherein at least one fluidic material remains between each said photoconductor, said at least one fluidic material having a lower refractive index as compared to the refractive index of each said photoconductor.
3 more elements
A method of fabricating a CMOS imaging device, comprising:
- forming a color filter layer wherein an individual color filter is formed over a corresponding one of a plurality of photo diodes;
- forming a plurality of photoconductors, wherein each photoconductor is formed between the corresponding individual color filter and the corresponding said photo diode;
- and
- forming at least one fluidic material between each of said photoconductors, said fluidic material surrounding at least a lower portion of each of said photoconductors, said at least one fluidic material having a refractive index lower than the refractive index of each of said photoconductors, wherein said refractive index of each said photoconductor operates to propagate light within an interior space of each said photoconductor to each corresponding said photo diodes, said interior space defined by the outer surfaces of each said photoconductor.
1 more element
A method of fabricating a CMOS imaging device, comprising:
- forming a color filter layer wherein an individual color filter is formed over a corresponding one of a plurality of photo diodes;
- forming a plurality of photoconductors, wherein each photoconductor is formed between the corresponding individual color filter and the corresponding said photo diode;
- and
- forming at least one fluidic material between each of said photoconductors, said at least one fluidic material having a refractive index lower than the refractive index of each of said photoconductors, wherein said at least one fluidic material is a gas, further wherein said refractive index of each said photoconductor operates to propagate light within an interior space of each said photoconductor to each corresponding said photo diode, said interior space defined by the outer surfaces of each said photoconductor.
1 more element
A method of fabricating a CMOS imaging device, comprising:
- forming a color filter layer wherein an individual color filter is formed over a corresponding one of a plurality of photo diodes;
- forming a plurality of photoconductors, wherein each photoconductor is formed between the corresponding individual color filter and the corresponding said photo diode;
- and
- forming at least one fluidic material between each of said photoconductors, said at least one fluidic material having a refractive index lower than the refractive index of each of said photoconductors, wherein said at least one fluidic material is air, further wherein said refractive index of each said photoconductor operates to propagate light within an interior space of each said photoconductor to each corresponding said photo diode, said interior space defined by the outer surfaces of each said photoconductor.
1 more element
A method of fabricating a photoconductor array in a CMOS imaging device, comprising:
- forming a plurality of photo diodes;
- forming a sacrificial layer over said plurality of photo diodes;
- removing at least a portion of said sacrificial layer to expose an opening over each of said photo diodes;
- forming a photoconductor over each said photo diode and within said openings;
- and
- removing said sacrificial layer surrounding each said photoconductor, and surrounding each said photoconductor with a fluidic material, said fluidic material having a lower refractive index as compared to the refractive index of each said photoconductor.
3 more elements
A method of fabricating a CMOS imaging device, comprising:
- forming a color filter layer wherein an individual color filter is formed over a corresponding one of a plurality of photo diodes;
- forming a plurality of photoconductors, wherein each photoconductor is formed between the corresponding individual color filter and the corresponding said photo diode;
- and
- forming a fluidic material, said fluidic material surrounding at least a lower portion of each of said photoconductors, said fluidic material having a lower refractive index than the refractive index of each of said photoconductors, wherein said refractive index of each said photoconductor operates to propagate light within an interior space of each said photoconductor to each corresponding said photo diode, said interior space defined by the outer surfaces of each said photo conductor.
1 more element
A method of fabricating a CMOS imaging device, comprising:
- forming a color filter layer wherein an individual color filter is formed over a corresponding one of a plurality of photo diodes;
- forming a plurality of photoconductors, wherein each photoconductor is formed between the corresponding individual color filter and the corresponding said photo diode;
- and
- forming a fluidic material, such that said fluidic material surrounds each of said photoconductors, said fluidic material having a lower refractive index than the refractive index of each of said photoconductors, wherein said fluidic material is a gas, further wherein said refractive index of each said photoconductor operates to propagate light within an interior space of each said photoconductor to each corresponding said photo diode, said interior space defined by the outer surfaces of each said photoconductor.
1 more element
A method of fabricating a CMOS imaging device, comprising:
- forming a color filter layer wherein an individual color filter is formed over a corresponding one of a plurality of photo diodes;
- forming a plurality of photoconductors, wherein each photoconductor is formed between the corresponding individual color filter and the corresponding said photo diode;
- and
- forming a fluidic material, such that said fluidic material surrounds each of said photoconductors, said fluidic material having a lower refractive index than the refractive index of each of said photoconductors, wherein said fluidic material is air, further wherein said refractive index of each said photoconductor operates to propagate light within an interior space of each said photoconductor to each corresponding said photo diode, said interior space defined by the outer surfaces of each said photoconductor.
1 more element
Dependencies are inferred from the claim text.