US3812518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photodiode with patterned structure
Assignee: General Electric Co
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Filing: 1973-01-02
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Granted: 1974-05-21
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Expires: 1993-01-02
Abstract
Abstract A monolithic or discrete photodiode has a patterned region, preferably in the form of elongated strips or fingers, with a spacing less than the diffusion length to obtain low capacitance without loss of photo response. Enhanced efficiency is achieved by the use of surface skin regions and/or a buried layer to confine generated carriers, and by a structure that effects combination of the epitaxial layer-substrate photodiode with the finger photodiode. The low capacitance photodiode is sensitive to visible and infrared light and is useful in high speed circuit applications.
Inventors
- 👤 B Kurz
- 👤 A Ferro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:10
CPC Classifications
H; H10; H10F; H10F30/00; H10F30/20; H10F30/21; H10F30/22; H10F30/221; H10F99/00; H10D; H10D99/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
113 words
A low capacitance photodiode comprising a semiconductor layer of one conductivity type, a plurality of spaced opposite conductivity type regions formed into the surface of said layer each providing a light sensitive junction therewith, and means for making contact to said layers and to said spaced regions for the application of a reverse biasing potential, thereby forming a depletion region at each light sensitive junction, said spaced regions being spaced from one another by a distance on the order of the diffusion length of carriers generated in said layer by incident visible and infrared light, to thereby collect carriers generated by light incident on the surface of said layer between said depletion regions.
Claim 2
Dependent Claim
113 words
A low capacitance photodiode comprising a semiconductor layer of one conductivity type, a plurality of spaced opposite conductivity type regions formed into the surface of said layer each providing a light sensitive junction therewith, and means for making contact to said layers and to said spaced regions for the application of a reverse biasing potential, thereby forming a depletion region at each light sensitive junction, said spaced regions being spaced from one another by a distance on the order of the diffusion length of carriers generated in said layer by incident visible and infrared light, to thereby collect carriers generated by light incident on the surface of said layer between said depletion regions.
Claim 3
Dependent Claim
38 words
A photodiode according to claim 1 further including other regions with the same conductivity type as said layer formed into the surface thereof between said spaced opposite conductivity type regions to prevent surface recombination of said generated carriers.
Claim 4
Dependent Claim
93 words
A monolithic photodiode comprising a semiconductor layer of one conductivity type on a substrate of the opposite conductivity type, a plurality of spaced opposite conductivity type regions formed into the surface of said layer each providing a light sensitive junction therewith having a narrow depletion layer, said regions being spaced from one another by a distance less than the diffusion length of carriers generated in said layer by incident visible and infrared light, and means for making contact to said layer and to said spaced regions for the application of reverse biasing potential.
Claim 5
Dependent Claim
93 words
A monolithic photodiode comprising a semiconductor layer of one conductivity type on a substrate of the opposite conductivity type, a plurality of spaced opposite conductivity type regions formed into the surface of said layer each providing a light sensitive junction therewith having a narrow depletion layer, said regions being spaced from one another by a distance less than the diffusion length of carriers generated in said layer by incident visible and infrared light, and means for making contact to said layer and to said spaced regions for the application of reverse biasing potential.
Claim 6
Dependent Claim
22 words
A photodiode according to claim 3 wherein said spaced regions are in the form of elongated strips arranged parallel to one another.
Claim 7
Dependent Claim
38 words
A photodiode aCcording to claim 3 further including other regions with the same conductivity type as said layer formed into the surface thereof between said spaced opposite conductivity type regions to prevent surface recombination of said generated carriers.
Claim 8
Dependent Claim
54 words
A photodiode according to claim 3 further including an additional opposite conductivity region extending through said layer and connecting to said substrate to collect generated carriers at an underlying light sensitive junction between said layer and substrate, and means for making contact to said additional region for the application of the reverse biasing potential.
Claim 9
Dependent Claim
59 words
A photodiode according to claim 3 wherein said means for making contact to said spaced regions includes an opposite conductivity type isolation region surrounding said spaced regions. said isolation region also connecting to said substrate to collect generated carriers at an underlying light sensitive junction between said layer and substrate to which the reverse biasing potential is also applied.
Claim 10
Dependent Claim
34 words
A photodiode according to claim 3 further including a buried layer between said first-mentioned layer and substrate, having the same conductivity type as said first-mentioned layer and tending to confine said generated carriers thereto.
Claim 11
Dependent Claim
96 words
A monolithic photodiode comprising an n-type layer on a p-type semiconductor substrate, a plurality of spaced elongated p-type strips formed into the surface of said layer and each providing a light sensitive junction therewith having a narrow depletion region, said elongated strips being spaced from one another by a distance less than the diffusion length of carriers generated in said layer by incident visible and infrared light, and first contact means for making connection to said spaced elongated strips, and second contact means making connection to said layer for the application of a reverse biasing potential.
Claim 12
Dependent Claim
96 words
A monolithic photodiode comprising an n-type layer on a p-type semiconductor substrate, a plurality of spaced elongated p-type strips formed into the surface of said layer and each providing a light sensitive junction therewith having a narrow depletion region, said elongated strips being spaced from one another by a distance less than the diffusion length of carriers generated in said layer by incident visible and infrared light, and first contact means for making connection to said spaced elongated strips, and second contact means making connection to said layer for the application of a reverse biasing potential.
Claim 13
Dependent Claim
32 words
A photodiode according to claim 9 further including other shallow n-type regions formed into the surface of said layer between said spaced elongated strips to prevent surface recombination of said generated carriers.
Claim 14
Dependent Claim
54 words
A photodiode according to claim 9 wherein said first contact means comprises a p-type isolation region having connection to the ends of said spaced elongated strips, said isolation region extending through said layer and connecting to said substrate to collect generated carriers at an underlying reverse-biased light sensitive junction between said layer and substrate.
Claim 15
Dependent Claim
65 words
A photodiode according to claim 9 wherein said first contact means comprises a p-type isolation region entirely surrounding said spaced elongated strips and second contact means and making connection to the ends of said spaced elongated strips, said isolation region extending through said layer and connecting to said substrate to collect generated carriers at an underlying reverse-biased light sensitive junction between said layer and substrate.
Claim 16
Dependent Claim
29 words
A photodiode according to claim 7 further including a buried n-type layer between said first-mentioned layer and substrate that tends to confine said generated carriers to said first-mentioned layer.
Claim 17
Dependent Claim
54 words
A photodiode according to claim 9 further including other shallow n-type regions formed into the surface of said layer between said spaced elongated strips to prevent surface recombination of said generated carriers, and a buried n-type layer between said first-mentioned layer and substrate that tends to confine said generated carriers to said first-mentioned layer.
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) | 1977-05-20 | 1977-11-19 | 1978-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-20 | 1981-11-19 | 1982-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-20 | 1985-11-19 | 1986-05-21 | $7700.00 | Window Closed / Lapsed |