US3739240A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Buried channel charge coupled devices
Assignee: AT&T Inc
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Filing: 1971-04-06
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Granted: 1973-06-12
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Expires: 1991-04-06
Abstract
Abstract The specification describes charge coupled devices in which the storage layer is internally charged so that the energy level profile across the thickness of the layer has a maxima in the middle of the layer. Injected carriers can then be stored and transferred in the bulk region of the semiconductor. If the energy level of the maxima exceeds the surface energy of the valence band by an amount exceeding the Boltzmann expression for thermal excitation, then the stored carriers remain isolated (statistically) from the surface states. The storage layer can be appropriately charged by biasing the layer to remove the mobile carriers. Residual fixed charge bends the energy band if the boundaries are fixed to appropriate barriers. The most convenient structure appears to be a large area p-n junction for the lower (buried) barrier with the usual MIS surface barrier. An MISIM structure is predictably similar. Multichannel structures are proposed such as N-P-N-P-N in which the isolated P-channels serve simultaneously as storage layers. Simultaneous use of both channels with controlled interconnection suggests many potential applications for logic circuits and the availability of convenient crossovers.
Inventors
- 👤 R Krambeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 02:32
CPC Classifications
H; H10; H10P; H10P95/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
260 words
A charge coupled device comprising: a planar charge storage medium; a multiplicity of discrete electrode field plates arranged adjacent to the charge storage medium, each capable when electrically biased of forming an associated charge storage site within the charge storage medium, the field plates being spaced sequentially in a direction parallel to the plane of the charge storage medium with each adjacent to at least two other field plates so that, with appropriate electrical bias applied to at least two of said field plates, electrical charge can be made to pass controllably between selected charge storage sites and ultimately to a detection site; input means for introducing mobile electrical charge into the charge storage medium; detection meAns for detecting the presence or absence of charge in the storage medium at a detection site; charge transfer means including said field plates for transferring within the storage medium, the electrical charge between storage sites, and to the detection site; the invention characterized in that the storage medium is bounded on all sides with electrical barriers except for a limited area ohmic contact adapted for electrically biasing the storage medium to deplete the storage medium and, with the electrical bias applied to the field plates, to create potential minima for the stored electrical charge, the potential minima existing physically within the storage medium interior of the boundary electrical barriers whereby said charge storage sites exist physically within said interior, and further characterized in that the electrode field plates are disposed directly on the planar surface of the storage medium forming Schottky barriers therewith.
Claim 2
Dependent Claim
260 words
A charge coupled device comprising: a planar charge storage medium; a multiplicity of discrete electrode field plates arranged adjacent to the charge storage medium, each capable when electrically biased of forming an associated charge storage site within the charge storage medium, the field plates being spaced sequentially in a direction parallel to the plane of the charge storage medium with each adjacent to at least two other field plates so that, with appropriate electrical bias applied to at least two of said field plates, electrical charge can be made to pass controllably between selected charge storage sites and ultimately to a detection site; input means for introducing mobile electrical charge into the charge storage medium; detection meAns for detecting the presence or absence of charge in the storage medium at a detection site; charge transfer means including said field plates for transferring within the storage medium, the electrical charge between storage sites, and to the detection site; the invention characterized in that the storage medium is bounded on all sides with electrical barriers except for a limited area ohmic contact adapted for electrically biasing the storage medium to deplete the storage medium and, with the electrical bias applied to the field plates, to create potential minima for the stored electrical charge, the potential minima existing physically within the storage medium interior of the boundary electrical barriers whereby said charge storage sites exist physically within said interior, and further characterized in that the electrode field plates are disposed directly on the planar surface of the storage medium forming Schottky barriers therewith.
Claim 3
Dependent Claim
33 words
The charge coupled device of claim 1 in which the planar storage medium is a p-type semiconductor and the input means is adapted for introducing mobile positive charge into the charge storage medium.
Claim 4
Dependent Claim
33 words
The charge coupled device of claim 1 in which the planar storage medium is an n-type semiconductor and the input means is adapted for introducing mobile negative charge into the charge storage medium.
Claim 5
Dependent Claim
22 words
The device of claim 1 further including an insulating layer covering the spaced portions of the storage medium between the field plates.
Claim 6
Dependent Claim
13 words
The device of claim 1 in which the charge storage medium is silicon.
Claim 7
Dependent Claim
39 words
The device of claim 5 in which the field plates comprise a metal selected from the group consisting of Cu, Mo, W, No, the six-platinum group metals and mixtures thereof and the Schottky barrier comprises a metal silicide-silicon interface.
Claim 8
Dependent Claim
273 words
A charge coupled device comprising: a planar charge storage medium; a multiplicity of discrete electrode field plates arranged adjacent to the charge storage medium, each capable when electrically biased of forming an associated charge storage site within the charge storage medium, the field plates being spaced sequentially in a direction parallel to the plane of the charge storage medium with each adjacent to at least two other field plates so that, with appropriate electrical bias applied to at least two of said field plates, electrical charge can be made to pass controllably between selected charge storage sites and ultimately to a detection site; input means for introducing mobile electrical charge into the charge storage medium; detection means for detecting the presence or absence of charge in the storage medium at a detection site; charge transfer means including said field plates for transferring within the storage medium, the electrical charge between storage sites, and to the detection site; the invention characterized in that the storage medium is a semiconductor bounded on all sides with electrical barriers except for a limited area ohmic contact adapted for electrically biasing the storage medium to deplete the storage medium and, with the electrical bias applied to the field plates, to create potential minima for the stored electrical charge, the potential minima existing physically within the storage medium interior of the boundary electrical barriers whereby said charge storage sites exist physically within said interior, and further characterized in that each electrode field plate is disposed on a separate impurity region formed into the planar surface of the storage medium so as to form therewith a p-n junction electrical barrier.
Claim 9
Dependent Claim
273 words
A charge coupled device comprising: a planar charge storage medium; a multiplicity of discrete electrode field plates arranged adjacent to the charge storage medium, each capable when electrically biased of forming an associated charge storage site within the charge storage medium, the field plates being spaced sequentially in a direction parallel to the plane of the charge storage medium with each adjacent to at least two other field plates so that, with appropriate electrical bias applied to at least two of said field plates, electrical charge can be made to pass controllably between selected charge storage sites and ultimately to a detection site; input means for introducing mobile electrical charge into the charge storage medium; detection means for detecting the presence or absence of charge in the storage medium at a detection site; charge transfer means including said field plates for transferring within the storage medium, the electrical charge between storage sites, and to the detection site; the invention characterized in that the storage medium is a semiconductor bounded on all sides with electrical barriers except for a limited area ohmic contact adapted for electrically biasing the storage medium to deplete the storage medium and, with the electrical bias applied to the field plates, to create potential minima for the stored electrical charge, the potential minima existing physically within the storage medium interior of the boundary electrical barriers whereby said charge storage sites exist physically within said interior, and further characterized in that each electrode field plate is disposed on a separate impurity region formed into the planar surface of the storage medium so as to form therewith a p-n junction electrical barrier.
Claim 10
Dependent Claim
33 words
The charge coupled device of claim 7 in which the planar storage medium is a p-type semiconductor and the input means is adapted for introducing mobile positive charge into the charge storage medium.
Claim 11
Dependent Claim
33 words
The charge coupled device of claim 7 in which the planar storage medium is an n-type semiconductor and the input means is adapted for introducing mobile negative charge Into the charge storage medium.
Claim 12
Dependent Claim
13 words
The device of claim 7 in which the charge storage medium is silicon.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |