CCD Readout structure for display applications

Claim 2

A liquid crystal light valve activated by a charge-coupled device (CCD) comprising: (a) a semiconductor substrate characterized by first and second major opposite surfaces; (b) a CCD arrangement formed on said first major substrate surface and including a set of CCD electrodes for storage and transfer of charge carriers in charge depletion buckets adjacent to said set of CCD electrodes; (c) a liquid crystal layer adjacent to said second major substrate surface; (d) means for establishing within said substrate an electric field substantially below avalanche breakdown wherein the value of said field is selected to form a depletion region and an undepleted region between said first and second major substrate surfaces, said undepleted region separating said charge depletion buckets from said depletion regions; and (e) means for biasing said CCD electrodes so that said charge carriers are transferred from adjacent to said CCD electrodes through said undepleted region to said depletion region where they are then electric-field guided without avalanching through said depletion region to said second major substrate surface without substantial lateral spreading in order to activate said liquid crystal layer.

Claim 3

A liquid crystal light valve activated by a charge-coupled device (CCD) comprising: (a) a semiconductor substrate characterized by first and second major opposite surfaces; (b) a CCD structure formed adjacent to said first major substrate surface including a set of CCD electrodes and an insulating layer adjacent to said first surface for the insulation of said set of CCD electrodes; (c) a semiconductor interface layer between said insulating layer and said first major substrate surface for storage and transfer of said charge carriers in charge depletion buckets adjacent to said CCD electrodes; (d) a liquid crystal layer adjacent to said second major substrate surface; and (e) means for establishing an electric field substantially below avalanche breakdown in said substrate transverse to said major surfaces wherein the value of said field is selected to form a charge depletion region which extends between said major surfaces of said substrate and an undepleted region within said semiconductor interface layer, said undepleted region separating said charge depletion buckets from said depletion region within said substrate so that, when proper bias conditions are applied on said CCD electrodes, said charge carriers adjacent to said CCD electrodes diffuse through said interface layer to said charge depletion region where they are then electric-field guided without avalanching through said substrate without substantial lateral spreading in order to activate said liquid crystal layer.

Claim 4

A liquid crystal light valve activated by a charge-coupled device (CCD) comprising: (a) a semiconductor substrate characterized by first and second major opposite surfaces; (b) a CCD structure formed adjacent to said first major substrate surface including a set of CCD electrodes and an insulating layer adjacent to said first surface for the insulation of said set of CCD electrodes; (c) a semiconductor interface layer between said insulating layer and said first major substrate surface for storage and transfer of said charge carriers in charge depletion buckets adjacent to said CCD electrodes; (d) a liquid crystal layer adjacent to said second major substrate surface; and (e) means for establishing an electric field substantially below avalanche breakdown in said substrate transverse to said major surfaces wherein the value of said field is selected to form a charge depletion region which extends between said major surfaces of said substrate and an undepleted region within said semiconductor interface layer, said undepleted region separating said charge depletion buckets from said depletion region within said substrate so that, when proper bias conditions are applied on said CCD electrodes, said charge carriers adjacent to said CCD electrodes diffuse through said interface layer to said charge depletion region where they are then electric-field guided without avalanching through said substrate without substantial lateral spreading in order to activate said liquid crystal layer.

Claim 5

A device as set forth in claim 2 wherein said means for establishing said electric field within said substrate is a reverse biased continuous PN junction formed in a portion of said substrate.

Claim 6

A device as set forth in claim 2 wherein said rectifying means for establishing said electric field within said substrate comprises a series of discrete and reverse biased PN junctions.

Claim 7

A device as set forth in claim 2 wherein said means for establishing said electric field within said substrate is a reverse biased Schottky barrier gate diode structure formed on said second major surface of said substrate.

Claim 8

A device as set forth in claim 2 wherein interface layers are between said liquid crystal layer and said semiconductor substrate for preventing light from entering said substrate through said major substrate surface adjacent said liquid crystal layer and for reflecting said light.

Claim 9

A liquid crystal light valve activated by a charge-coupled device (CCD) comprising: (a) a semiconductor substrate characterized by first and second major opposite surfaces; (b) a CCD structure formed adjacent to said first major substrate surface including a set of CCD electrodes and an insulating layer adjacent to said first surface for the insulation of said set of CCD electrodes; (c) a semiconductor interface layer between said insulating layer and said first major substrate surface for storage and transfer of said charge carriers in charge depletion buckets adjacent to said CCD electrodes; (d) a liquid crystal layer adjacent to said second major substrate surface; (e) a rectifying junction formed in a portion of said substrate; (f) means for reverse-biasing said junction to establish an electric field substantially below avalanche breakdown wherein the value of said field, the thicknesses of said semiconductor interface layer and said semiconductor substrate, and the resistivities of said semiconductor interfere layer and said semiconductor substrate are selected to form a depletion region between said first and second major substrate surfaces and an undepleted region within said semiconductor interface layer, said undepleted region separating said charge depletion buckets adjacent to said CCD electrodes from said depletion region within said substrate; and (g) means for biasing said CCD electrodes so that said charge carriers diffuse from said interface layer through said undepleted region to said substrate depletion region where they are then electric-field guided without avalanching through said depletion region to said second major substrate surface without substantial lateral spreading in order to activate said liquid crystal layer.

Claim 10

A liquid crystal light valve activated by a charge-coupled device (CCD) comprising: (a) a semiconductor substrate characterized by first and second major opposite surfaces; (b) a CCD structure formed adjacent to said first major substrate surface including a set of CCD electrodes and an insulating layer adjacent to said first surface for the insulation of said set of CCD electrodes; (c) a semiconductor interface layer between said insulating layer and said first major substrate surface for storage and transfer of said charge carriers in charge depletion buckets adjacent to said CCD electrodes; (d) a liquid crystal layer adjacent to said second major substrate surface; (e) a rectifying junction formed in a portion of said substrate; (f) means for reverse-biasing said junction to establish an electric field substantially below avalanche breakdown wherein the value of said field, the thicknesses of said semiconductor interface layer and said semiconductor substrate, and the resistivities of said semiconductor interfere layer and said semiconductor substrate are selected to form a depletion region between said first and second major substrate surfaces and an undepleted region within said semiconductor interface layer, said undepleted region separating said charge depletion buckets adjacent to said CCD electrodes from said depletion region within said substrate; and (g) means for biasing said CCD electrodes so that said charge carriers diffuse from said interface layer through said undepleted region to said substrate depletion region where they are then electric-field guided without avalanching through said depletion region to said second major substrate surface without substantial lateral spreading in order to activate said liquid crystal layer.

Claim 11

A device as set forth in claim 7 wherein said interface layer is an epitaxial layer formed on said first surface of said substrate.

Claim 12

A device as set forth in claim 8 wherein: (a) said semiconductor substrate is silicon; (b) said epitaxial layer is silicon; (c) said insulating layer is silicon dioxide; and (d) said rectifying junction is a PN junction.

Claim 13

A device as set forth in claim 7 wherein said substrate has a resistivity greater than 1000 ohm-centimeter.

Claim 14

A device as set forth in claim 7 wherein said interface layer has a thickness less than one-sixth the thickness of said substrate and said interface layer has a resistivity less than the resistivity of said substrate.