An image sensor includes a semiconductor substrate; a photosensor having, a first
photosensing region including a first stack of one or more layers of transparent
materials covering the substrate, the first photosensing region having a spectral
response having minima and maxima as a function of wavelength of light; a second
photosensing region including a second stack of one or more layers of transparent
materials covering the substrate, the second photosensing region having a spectral
response having maxima and minima; and a third photosensing region including a
third stack of one or more layers of transparent materials covering the substrate,
the third photosensing region having a spectral response having maxima and minima;
and wherein at least one maximum or minimum of the spectral response of the separate
regions is matched with a minimum or maximum such that the average spectral response
of the photosensor has less variation with wavelength of light than the individual
spectral responses of each of the separate photosensing regions.
