Multispectral imaging CMOS sensor

1 . A multipixel image sensor comprising:

an array of photodiodes formed in a front-end or back-end CMOS process;

a plurality of color filters over each photodiode in the array of photodiodes and arranged in a laterally extending array of uniform thickness;

wherein each of the plurality of color filters being formed of a material that is compatible with the CMOS process;

wherein each of the plurality of color filters has a selected bandpass range of no more than 40 nanometers Full-Width-Half-Maximum centered in a predefined wavelength that is greater than or equal to 400 nanometers and a 50% or more light transmission on a silicon wafer;

wherein at least one of the plurality of color filters has a first bandpass range, at least one of the plurality of color filters has a second bandpass range that is different from the first bandpass range, and at least one of the plurality of color filters has a third bandpass range that is different from the first bandpass range and the second bandpass range; and

wherein each of the plurality of color filters includes a first material having a first refractive index (np or nq) surrounded by a second material having a second refractive index (nq or np) that is different from the first refractive index, wherein the combined refractive index of the first and second materials differs from the first and second refractive indices and matches a respective one of the bandpass ranges, and wherein the first material includes a metal material therein.

2 . The multipixel image sensor of claim 1 , wherein each of the plurality of color filters is an equivalent index filter.

3 . The multipixel image sensor of claim 1 , wherein each of the plurality of color filters is a multicavity filter.

4 . The multipixel image sensor of claim 1 , wherein each of the plurality of color filters is a multispectral color filter.

5 . A method of fabricating a multipixel image sensor comprising:

forming an array of photodiodes in a front-end or back-end CMOS process;

forming a plurality of color filters over each photodiode in the array of photodiodes and arranged in a laterally extending array of uniform thickness;

wherein each of the plurality of color filters being formed of a material that is compatible with the CMOS process;

wherein each of the plurality of color filters has a selected bandpass range of no more than 40 nanometers Full-Width-Half-Maximum centered in a predefined wavelength that is greater than or equal to 400 nanometers and a 50% or more light transmission on a silicon wafer;

wherein at least one of the plurality of color filters has a first bandpass range, at least one of the plurality of color filters has a second bandpass range that is different from the first bandpass range, and at least one of the plurality of color filters has a third bandpass range that is different from the first bandpass range and the second bandpass range; and

wherein each of the plurality of color filters includes a first material having a first refractive index (np or nq) surrounded by a second material having a second refractive index (nq or np) that is different from the first refractive index, and wherein the combined refractive index of the first and second materials differs from the first and second refractive indices and matches a respective one of the bandpass ranges, and wherein the first material is a cavity including a metal material therein.

6 . The method of fabricating the multipixel image sensor of claim 5 , wherein the step of forming the plurality of color filters comprises forming equivalent index filters.

7 . The method of fabricating the multipixel image sensor of claim 5 , wherein the step of forming the plurality of color filters comprises forming multicavity filters.

8 . The method of fabricating the multipixel image sensor of claim 5 , wherein the step of forming the plurality of color filters comprises forming multispectral color filters.