US5202282A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing a self-alignment type CCD sensor
Assignee: Intellectual Ventures II LLC
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Filing: 1991-07-10
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Granted: 1993-04-13
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Expires: 2011-07-10
Abstract
Abstract A process for producing a CCD image sensor comprising the steps of: providing a light-receiving photo-diode region and a VCCD transmission region by injecting ions into a substrate at a predetermined distance, the injected ions being different in type from the substrate, covering the surface of the substrate with a gate oxide layer and a gate polysilicon layer, the gate polysilicon layer being deposited over the gate oxide layer, then removing the gate polysilicon layer only from the region over the light-receiving region, depositing a refractory metal layer over the whole etched surface by vacuum evaporation and then annealing the refractory metal into a silicide in the region thereof which is in contact with the gate polysilicon and removing the refractory metal from the unconverted portion of the refractory metal layer which overlies the gate oxide layer. In this process, a fill factor of the light-receiving region is maximized as a window is provided in the light-receiving region by self-alignment, and smear is prevented as silicide completely covers the gate polysilicon layer including even the side faces thereof.
Inventors
- 👤 Dong K. Son
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:43
CPC Classifications
H; H10; H10D; H10D44/00; H10D44/01; H10D44/041; H10F; H10F39/00; H10F39/10; H10F39/12; H10F39/15; H10F39/153
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
135 words
A process for producing a self-alignment type CCD image sensor comprising the steps of: providing a light-receiving region and a transmission region by injecting ions into a substrate at a predetermined distance, the injected ions being different in type from the substrate; covering the surface of the substrate with a gate oxide and a gate polysilicon, the gate polysilicon being over the gate oxide, then eliminating the gate polysilicon only at the portion over the photo-receiving region through photo and etching processes; producing a refractory metal on the whole etched surface by vacuum evaporation and then converting the refractory metal into a silicide at the portion in contact with the gate polysilicon through annealing process; and eliminating the refractory metal at the unconverted portion which remains on the gate oxide through a predetermined etching process.
Claim 2
Dependent Claim
135 words
A process for producing a self-alignment type CCD image sensor comprising the steps of: providing a light-receiving region and a transmission region by injecting ions into a substrate at a predetermined distance, the injected ions being different in type from the substrate; covering the surface of the substrate with a gate oxide and a gate polysilicon, the gate polysilicon being over the gate oxide, then eliminating the gate polysilicon only at the portion over the photo-receiving region through photo and etching processes; producing a refractory metal on the whole etched surface by vacuum evaporation and then converting the refractory metal into a silicide at the portion in contact with the gate polysilicon through annealing process; and eliminating the refractory metal at the unconverted portion which remains on the gate oxide through a predetermined etching process.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein Mo is used as the refractory metal.
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein Pt is used as the refractory metal.
Claim 5
Dependent Claim
13 words
The process of claim 1 wherein Ti is used as the refractory metal.
Claim 6
Dependent Claim
137 words
A process for producing a self-alignment type CCD image sensor comprising the steps of: providing a light-receiving region and a transmission region by injecting ions into a substrate at a predetermined distance, the injected ions being different in type from the substrate; covering the surface of the substrate with a gate oxide layer and a gate polysilicon layer, the gate polysilicon layer being deposited over the gate oxide layer, then removing the gate polysilicon layer only from the region over the light-receiving region; depositing a refractory metal layer over the whole etched surface by vacuum evaporation and then annealing the refractory metal into a silicide in the region thereof which is in contact with the gate polysilicon; and removing the refractory metal from the unconverted portion of the refractory metal layer which overlies the gate oxide layer.
Claim 7
Dependent Claim
137 words
A process for producing a self-alignment type CCD image sensor comprising the steps of: providing a light-receiving region and a transmission region by injecting ions into a substrate at a predetermined distance, the injected ions being different in type from the substrate; covering the surface of the substrate with a gate oxide layer and a gate polysilicon layer, the gate polysilicon layer being deposited over the gate oxide layer, then removing the gate polysilicon layer only from the region over the light-receiving region; depositing a refractory metal layer over the whole etched surface by vacuum evaporation and then annealing the refractory metal into a silicide in the region thereof which is in contact with the gate polysilicon; and removing the refractory metal from the unconverted portion of the refractory metal layer which overlies the gate oxide layer.
Claim 8
Dependent Claim
20 words
The process of claim 5 wherein the refractory metal is selected from the group comprised of Mo, Pt, or Ti.
Claim 9
Dependent Claim
19 words
The process of claim 5 wherein the process for removing the gate polysilicon layer is a dry etching process.
Claim 10
Dependent Claim
16 words
The process of claim 7 wherein the dry etching process is a reactive ion etching process.
Claim 11
Dependent Claim
19 words
The process of claim 5 wherein the process for removing the unconverted refractory metal is a wet etching process.
Claim 12
Dependent Claim
25 words
The process of claim 9 wherein the wet etching process is carried out with an etchant mixture of deionized water, hydrogen peroxide and ammonium hydroxide.
Claim 13
Dependent Claim
14 words
The process of claim 5 wherein the light receiving region is a photo diode.
Claim 14
Dependent Claim
14 words
The process of claim 5 wherein the light receiving region is a Schottky diode.
Claim 15
Dependent Claim
16 words
The process of claim 5 wherein the light transmission region is a vertical charge coupled device.
Claim 16
Dependent Claim
16 words
The process of claim 5 wherein the light transmission region is a buried charge coupled device.
Claim 17
Dependent Claim
19 words
The process of claim 5 wherein a heat treating step is performed on the sensor as a final step.
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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) | 1996-04-12 | 1996-10-12 | 1997-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-12 | 2000-10-12 | 2001-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-12 | 2004-10-12 | 2005-04-13 | $7700.00 | Window Closed / Lapsed |