Color responsive imaging device employing wavelength dependent semiconductor optical absorption

A solid state color responsive imaging device, comprising:

• a. a semiconductor substrate having a light receiving surface;
• b. first photoresponsive means disposed at a first depth beneath said surface for generating a first photosignal in response to light of a first range of wavelengths impinging on said surfae;
• and
• c. second photoresponsive means disposed directly beneath said first means at a second depth beneath said surface for generating a second photosignal in response to light, in a range of wavelengths narrower than said first range due to the differential absorption by said semiconductor, impinging on said surface,
• thereby providing an imaging device having enhanced spatial resolution and high efficiency of utilization of incident light.

A solid state color responsive imaging device, comprising:

• a. a semiconductor substrate having a light receiving surface;
• b. first photoresponsive means disposed at a first depth beneath said surface for generating a first photosignal in response to light of a first range of wavelengths impinging on said surface;
• c. second photoresponsive means disposed directly beneath said first means at a second depth beneath said surface for generating a second photosignal in response to light, of a second range of wavelengths different from said first range, impinging on said surface, and
• d. charge coupled device means for moving said first and second photosignals simultaneously within said device at said respective depths, whereby phase differences between respective color signals arising from respective photoresponsive means beneath a common point on said surface of said device are obviated.

A solid state imaging device comprising:

• a. a chip of semiconductor material comprising at least six layers of alternately different dopant types;
• b. means for scavenging mobile majority charge carriers from said first, third and fifth layers to form respective buried charge transporting channels in those layers;
• c. nonconductive transparent means covering the surface of the said first layer;
• and
• d. transparent electrode means on said transparent nonconductive means.

An image sensor device comprising:

• a. a wafer of silicon;
• b. a transparent oxide of silicon on said wafer;
• c. a plurality of rows of transparent electrode means on said oxide,
• said wafer having at least six contiguous layers, each being doped with impurity atoms, and each being doped with a type impurity different than any of its contiguous layers, said layers being disposed so that said oxide is contiguous with said first layer;
• and
• d. respective ohmic row contacts to the first, third and fifth layers for removing mobile majority carriers from those layers.

In combination:

• an imaging device comprising:
• A.
• a. a chip of silicon having at least six layers, each layer being doped with impurity atoms, and each being doped with an impurity type different than a layer contiguous therewith;
• b. a transparent oxide of silicon covering the first of said layers;
• c. transparent electrode means covering said oxide;
• the first layer being less than 0.7 .mu.m in thickness, the combined thickness of said first, second and third layers being less than 2.6 .mu.m, and the combined thickness of said first, second, third and fourth layers being greater than about 2.6 .mu.m;
• d. first, second and third ohmic contacts respectively to said first, third and fifth layers;
• and
• B.
• a. means coupled to said first and second ohmic contacts for algegraically combining signals appearing at those contacts;
• and
• b. means coupled to the said second and third ohmic contacts for algebraically combining signals appearing at those contacts.

A buried channel charge coupled imaging device comprising:

• a. first, second, third, fourth, fifth and sixth silicon layers which are respectively doped alternately with different type impurity atoms;
• b. a transparent nonconductive coating over the first of said layers;
• c. a row of transparent electrodes over said nonconductive coating;
• the first layer being less than about 0.7 .mu.m in thickness;
• the combined thickness of said first, second and third layers being less than 2.6 .mu.m;
• and the combined thickness of said first, second, third and fourth layers being greater than 2.6 .mu.m;
• the first, third and fifth layers, respectively fanning out to either side of and beyond said row of electrodes, and
• d. ohmic contacts respectively to the fanned out portions of the first, third and fifth layers.

A multi-spectral charge coupled device for generating a plurality of signals representative of the spectral content of a stream of photons impinging on the surface of said device comprising:

• a plurality of adjacent semiconductor layers arranged to generate a hole-electron pair for each photon of said photon stream, said hole-electron pair generated at a mean depth from the surface of said device which is a function of the wavelength of said respective photon;
• first and second collector means arranged to collect said generated holes or electrons, said first and second collector means arranged at different depths from the surface of said device whereby the efficiency of collection of said holes or electrons are respectively different functions of the depth from the surface of said device at which said holes and electrons are generated;
• and
• output means, operatively connected to said first and second collector means for providing output signals representative of said collected holes or electrons whereby said signals are indicative of the spectral content of said impinging stream of photons.