US5909041A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photogate sensor with improved responsivity
Assignee: Xerox Corp
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Filing: 1997-11-21
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Granted: 1999-06-01
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Expires: 2017-11-21
Abstract
Abstract A depleted-gate photosensor, or photogate, structure includes a polysilicon layer disposed over a silicon substrate. The polysilicon layer occupies only a portion of each exposure area of the substrate, and is preferably in the form of a ring around the exposure area. By having a portion of the exposure area not covered by the polysilicon, the blue-light-attenuation effects of a polysilicon layer are reduced.
Inventors
- 👤 Paul A. Hosier
- 👤 Jagdish C. Tandon
- 👤 Scott L. Tewinkle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 00:58
CPC Classifications
H; H10; H10F; H10F39/00; H10F39/80; H10F39/802; H10F39/803
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
123 words
A depleted-gate photosensor, comprising: a substrate comprising continuously-doped, single-crystal silicon, the substrate defining a main surface including an exposure area exposable to light; an oxide layer disposed on the main surface of the substrate, the oxide layer defining a gap in the main surface of the substrate, the layer including oxide immediately adjacent the gap within the exposure areas, the gap being defined in only a portion of the exposure area; a polysilicon layer disposed on the main surface, the polysilicon layer substantially covering the gap and extending over a portion of the exposure area and over a portion of the oxide layer immediately outside the gap; and a gate oxide layer disposed between the substrate and the polysilicon layer within the gap.
Claim 2
Dependent Claim
123 words
A depleted-gate photosensor, comprising: a substrate comprising continuously-doped, single-crystal silicon, the substrate defining a main surface including an exposure area exposable to light; an oxide layer disposed on the main surface of the substrate, the oxide layer defining a gap in the main surface of the substrate, the layer including oxide immediately adjacent the gap within the exposure areas, the gap being defined in only a portion of the exposure area; a polysilicon layer disposed on the main surface, the polysilicon layer substantially covering the gap and extending over a portion of the exposure area and over a portion of the oxide layer immediately outside the gap; and a gate oxide layer disposed between the substrate and the polysilicon layer within the gap.
Claim 3
Dependent Claim
27 words
The photosensor of claim 1, the gap configured to form an enclosed area in the exposure area in a portion of the main surface of the substrate.
Claim 4
Dependent Claim
22 words
The photosensor of claim 1, the substrate and polysilicon layer forming, at an interface thereof, a gate having a predetermined threshold voltage.
Claim 5
Dependent Claim
15 words
The photosensor of claim 1, further comprising a transfer gate connected to the oxide layer.
Claim 6
Dependent Claim
23 words
The photosensor of claim 4, wherein the transfer gate includes a second polysilicon layer disposed immediately adjacent the polysilicon layer of the photosensor.
Claim 7
Dependent Claim
28 words
The photosensor of claim 1, the polysilicon layer configured to form an enclosed area in the exposure area in a portion of the main surface of the substrate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-05-31 | 2002-11-30 | 2003-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-05-31 | 2006-11-30 | 2007-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-05-31 | 2010-11-30 | 2011-06-01 | $7700.00 | Window Closed / Lapsed |