Charge coupled devices employing nonuniform concentrations of immobile charge along the information channel

Claim 2

In charge coupled apparatus of the type adapted for temporary storage and serial transfer in a predetermined direction of varying amounts of mobile charge carriers representing information and wherein the device includes a storage medium having a major surface, an insulating layer disposed over and contiguous with the surface, and a plurality of electrodes disposed over said layer so as to form a path along said predetermined direction, the improvement being that along said path and beneath each electrode there is disposed a laterally continuously monotonically varying distribution of immobile charge in sufficient nonuniformity and quantity such that in operation there is produced under said electrode a substantially asymmetric potential well, the asymmetRy in the potential well being such as to produce an electric field along the path in such a direction as to enhance the transfer of the mobile charge carriers in said predetermined direction.

Claim 3

In charge coupled apparatus of the type adapted for temporary storage and serial transfer in a predetermined direction of varying amounts of mobile charge carriers representing information and wherein the device includes a storage medium having a major surface, an insulating layer disposed over and contiguous with the surface, and a plurality of electrodes disposed over said layer so as to form a path along which said mobile charge carriers can be transferred in the storage medium in said predetermined direction in response to successively applied voltages, the improvement being that along said path and beneath the electrodes there are disposed a plurality of like regions of immobile charge, in each of which regions the concentration of immobile charge varies continuously and monotonically along said path in a manner sufficient that in operation with one of said voltages applied to each electrode there is produced under substantially all of each electrode along the path a continuously monotonically varying surface potential of sufficient variation that there is produced along the path an electric field sufficient to enhance the transfer of the mobile charge carriers in said predetermined direction.

Claim 4

In charge coupled apparatus of the type adapted for temporary storage and serial transfer in a predetermined direction of varying amounts of mobile charge carriers representing information and wherein the device includes a storage medium having a major surface, an insulating layer disposed over and contiguous with the surface, and a plurality of electrodes disposed over said layer so as to form a path along which said mobile charge carriers can be transferred in the storage medium in said predetermined direction in response to successively applied voltages, the improvement being that along said path and beneath the electrodes there are disposed a plurality of like regions of immobile charge, in each of which regions the concentration of immobile charge varies continuously and monotonically along said path in a manner sufficient that in operation with one of said voltages applied to each electrode there is produced under substantially all of each electrode along the path a continuously monotonically varying surface potential of sufficient variation that there is produced along the path an electric field sufficient to enhance the transfer of the mobile charge carriers in said predetermined direction.

Claim 5

Apparatus as recited in claim 2 wherein the concentration of immobile charge in each of said regions is linearly graded.

Claim 6

Apparatus as recited in claim 3 wherein the ions are disposed at least partially in the insulating layer.

Claim 7

Apparatus as recited in claim 2 wherein a separate one of said regions of immobile charge is disposed under each of said electrodes.

Claim 8

Apparatus as recited in claim 5 further comprising: a pair of conduction paths, each conduction path being connected to a different one of every second electrode in the succession of electrodes; and two-phase circuit means coupled to said conduction paths for successively biasing the electrodes sufficiently to cause storage and advance of mobile charge carriers representing information.

Claim 9

Apparatus as recited in claim 5 wherein separate ones of said regions of immobile charge are substantially coextensive with each of said electrodes.

Claim 10

Apparatus as recited in claim 2 wherein the immobile charge is provided by immobile ions.

Claim 11

Apparatus as recited in claim 2 wherein the storage medium includes a semiconductor including a bulk portion of relatively high resistivity and the regions are provided by doped surface regions of relatively lower resistivity.

Claim 12

Apparatus as recited in claim 9 wherein the bulk portion is of first type semiconductivity and the doped regions are of second type semiconductivity.

Claim 13

Apparatus as recited in claim 9 further comprising: a pair of conduction paths, each conduction path being connected to a different one of every second electrode in the succession of electrodes; and two-phase circuit means coupled to said conduction paths for successively biasing the electrodes sufficiently to cause the storage and advance of mobile charge carriers representing information.

Claim 14

Apparatus as recited in claim 11 wherein the minimum voltage supplied by the two-phase circuit means is sufficient to deplete the surface of the semiconductive storage medium to a depth at least as great as the depth to which the dopant impurities of second conductivity type extends into the semiconductive bulk portion.

Claim 15

Apparatus as recited in claim 2 wherein: the space between a pair of successive electrodes is substantially the same as the lateral dimension of each of said electrodes along the path; one of said regions of immobile charge is disposed under each electrode; and one of said regions of immobile charge is disposed under each of the spaces between the electrodes.

Claim 16

Apparatus as recited in claim 13 in combination with: a conduction path connected to each of said electrodes; and a single-phase circuit means coupled to said conduction path for alternately biasing simultaneously said electrodes to a greater and a lesser voltage.

Claim 17

Apparatus as recited in claim 14 wherein said greater voltage is sufficient to produce in said storage medium under each of said electrodes a surface potential greater than the surface potential produced by the regions of immobile charge in the spaces between the electrodes.

Claim 18

Apparatus as recited in claim 14 wherein the lesser of said voltages is insufficient to produce in said storage medium a surface potential as great as the surface potential produced by the regions of immobile charge in the spaces between the electrodes.

Claim 19

Apparatus as recited in claim 2 wherein each of said regions extends essentially only under one of said electrodes and the space between said one electrode and the next successive electrode.

Claim 20

Apparatus as recited in claim 2 wherein each region of immobile charge comprises a zone of said charge in which the concentration of immobile charge increases in the direction of desired charge propagation and extends under a plurality of said electrodes and under a plurality of said spaces between said electrodes.

Claim 21

Apparatus as recited in claim 2 wherein: the polarity of the immobile charge is opposite to the polarity of the mobile charge carriers; and the concentration of immobile charge in each of said regions increases in the predetermined direction.

Claim 22

Apparatus as recited in claim 19 wherein each of said regions comprises two distinct parts, in each of which the concentration of immobile charge is substantially uniform; and wherein in the part in the direction of desired charge propagation the concentration of immobile charge is greater than in the other of said parts.

Claim 23

Apparatus as recited in claim 2 wherein: the polarity of the immobile charge is the same as the polarity of the mobile charge carriers; and the concentration of immobile charge in each of said regions increases in a direction opposite to the predetermined direction.

Claim 24

Apparatus as recited in claim 21 wherein each of said regions comprises two distinct parts, in each of which the concentration of immobile charge is substantially uniform; and wherein, in the part in the direction opposite the desired direction of charge propagation, the concentration is greater than in the other of said parts.

Claim 25

In charge coupled apparatus of the type adapted for temporary storage and serial transfer in a predetermined direction of varying amounts of mobile charge carriers representing information and wherein the device includes a storage medium having a major surface, an insulating layer disposed over and contiguous with the surface, and a plurality of spaced electrodes disposed over said layer so as to form a path along said predetermined direction, the improvement being: a conduction path connected to each of said electrodes; a single-phase circuit means coupled to said conduction path for alternately biasing simultaneously said electrodes to a greater voltage and a lesser voltage; and disposed beneath each electrode and beneath each space between adjacent electrodes along said predetermined direction a continuously and monotonically varying distribution of immobile charge such that in response to the single-phase voltages there are produced under each electrode and under each space between adjacent electrodes a substantially asymmetric potential well, the asymmetry in the potential well being such as to produce an electric field along the information channel in such a direction as to enhance the transfer of the mobile charge carriers in said predetermined direction.

Claim 26

In charge coupled apparatus of the type adapted for temporary storage and serial transfer in a predetermined direction of varying amounts of mobile charge carriers representing information and wherein the device includes a storage medium having a major surface, an insulating layer disposed over and contiguous with the surface, and a plurality of spaced electrodes disposed over said layer so as to form a path along said predetermined direction, the improvement being: a conduction path connected to each of said electrodes; a single-phase circuit means coupled to said conduction path for alternately biasing simultaneously said electrodes to a greater voltage and a lesser voltage; and disposed beneath each electrode and beneath each space between adjacent electrodes along said predetermined direction a continuously and monotonically varying distribution of immobile charge such that in response to the single-phase voltages there are produced under each electrode and under each space between adjacent electrodes a substantially asymmetric potential well, the asymmetry in the potential well being such as to produce an electric field along the information channel in such a direction as to enhance the transfer of the mobile charge carriers in said predetermined direction.

Claim 27

In charge coupled apparatus of the type adapted for temporary storage and serial transfer in a predetermined direction of varying amounts of mobile charge carriers representing information and wherein the device includes a sTorage medium having a major surface, an insulating layer disposed over and contiguous with the surface, and a plurality of electrodes disposed over said layer so as to form a path along said predetermined direction, the improvement being: a plurality of regions of immobile charge under the electrodes for forming under the electrodes asymmetric potential wells, the asymmetry being such that relative to the desired direction of advance of stored mobile charge the leading portion of the well has a greater average depth than the trailing portion of the well; a plurality of regions of immobile charge disposed between adjacent electrodes for forming in the storage medium under the spaces between adjacent electrodes a potential well having mutual asymmetry with respect to adjacent potential wells formed under adjacent electrodes in response to the successively applied voltages; and a common conduction path connected to each of said electrodes, the asymmetry and mutual asymmetry in said potential wells being sufficient to enable storage and transfer of mobile charge carriers representing information in response to application of single-phase voltages to the electrodes.

Claim 28

In charge coupled apparatus of the type adapted for temporary storage and serial transfer in a predetermined direction of varying amounts of mobile charge carriers representing information and wherein the device includes a sTorage medium having a major surface, an insulating layer disposed over and contiguous with the surface, and a plurality of electrodes disposed over said layer so as to form a path along said predetermined direction, the improvement being: a plurality of regions of immobile charge under the electrodes for forming under the electrodes asymmetric potential wells, the asymmetry being such that relative to the desired direction of advance of stored mobile charge the leading portion of the well has a greater average depth than the trailing portion of the well; a plurality of regions of immobile charge disposed between adjacent electrodes for forming in the storage medium under the spaces between adjacent electrodes a potential well having mutual asymmetry with respect to adjacent potential wells formed under adjacent electrodes in response to the successively applied voltages; and a common conduction path connected to each of said electrodes, the asymmetry and mutual asymmetry in said potential wells being sufficient to enable storage and transfer of mobile charge carriers representing information in response to application of single-phase voltages to the electrodes.

Claim 29

Apparatus as recited in claim 24 wherein: the concentration of the immobile charge in each of the regions of the plurality of the regions of immobile charge varies continuously and monotonically along said path.

Claim 30

Apparatus as recited in claim 24 wherein the space between a pair of adjacent electrodes is substantially the same as the lateral dimension of each electrode along the path.

Claim 31

Charge coupled apparatus of the type adapted for temporary storage and serial transfer in a predetermined direction of varying amounts of mobile charge carriers representing information in response to an applied single-phase voltage source comprising: a storage medium having a major surface; an insulating layer disposed over and contiguous with the surface, said layer including a plurality of periodically recurring portions of first and second thicknesses; a continuous conductive layer forming a path extending along said predetermined direction over a plurality of said periodically recurring layer portions; under each of said portions a region of nonuniform immobile charge concentration in which the concentration varies along said predetermined direction, said regions of immobile charge being of quantity, concentration variation, and polarity sufficient that, in combination with the insulating layer and conductive layer, storage and sequential transfer of mobile charge carriers is enabled in response to application of single-phase voltage means to the conductive layer.

Claim 32

Charge coupled apparatus of the type adapted for temporary storage and serial transfer in a predetermined direction of varying amounts of mobile charge carriers representing information in response to an applied single-phase voltage source comprising: a storage medium having a major surface; an insulating layer disposed over and contiguous with the surface, said layer including a plurality of periodically recurring portions of first and second thicknesses; a continuous conductive layer forming a path extending along said predetermined direction over a plurality of said periodically recurring layer portions; under each of said portions a region of nonuniform immobile charge concentration in which the concentration varies along said predetermined direction, said regions of immobile charge being of quantity, concentration variation, and polarity sufficient that, in combination with the insulating layer and conductive layer, storage and sequential transfer of mobile charge carriers is enabled in response to application of single-phase voltage means to the conductive layer.

Claim 33

Apparatus as recited in claim 27 further comprising a single-phase clock means coupled thereto for alternately applying first and second voltages to said conductive layer sufficient to cause temporary storage and transfer of mobile charge carries along said predetermined direction.

Claim 34

Apparatus as recited in claim 27 wherein the second thickness is at least three times as great as the first thickness.