EP0404306A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Trench structured charge-coupled device
Assignee: Tektronix Inc
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Filing: 1990-04-23
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Granted: —
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Expires: 2010-04-23
Abstract
Abstract The charge transfer efficiency of a two-phase charge-coupled device cell is enhanced by providing a three-tiered built-in potential in the channel of each cell. Two lower potential tiers form a trenched potential well in the cell for storing charge. A higher potential tier between the trenched potential well of a cell and the potential well of a preceding neighbor cell provides a potential barrier preventing backflow of charge from well-to-well. The potential trench is located at the downstream end of the well adjacent a succeeding neighbor cell of the CCD.
Inventors
- 👤 Kei-Wean Calvin Yang
- 👤 John Edwards Taggart
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 05:14
CPC Classifications
H; H10; H10D; H10D44/00; H10D44/01; H10D44/041; H10D44/40; H10D44/45; H10D44/462; H10D44/464; H10D62/00; H10D62/10; H10D62/17; H10D62/213; H10D62/335
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
269 words
A cell for a charge-coupled device comprising: a semiconductor substrate; an insulation layer formed above said substrate; and an electrode formed above said insulation layer; the substrate including a channel region of length coextensive with said electrode in one lateral direction for conducting charge carriers under said electrode, the channel region comprising a barrier portion of substantial and continuous dimension in said lateral direction having a substantially homogeneous first built-in potential in said lateral direction providing minimal electric field in said lateral direction, the channel region further comprising a well portion of continuous dimension in said lateral direction and extending across 30% to 70% of the portion of the channel region in said lateral direction not included in said barrier portion, said well portion having a substantially homogeneous built-in second potential in said lateral direction providing minimal electric field in said lateral direction, and the channel region further comprising a trench portion at continuous dimension in said lateral direction and extending across 70% to 30% of the portion of the channel region in said lateral direction not included in said barrier portion, said well portion having a substantially homogeneous built-in third potential in said lateral direction providing minimal electric field in said lateral direction, said barrier, well and trench portions being respectively aligned in said lateral direction, said first and second potentials differing so as to provide a first electrical field between said barrier and well portions driving carriers in said lateral direction, said second and third potentials differing so as to provide a second electrical field between said well and trench portions driving carriers in said lateral direction.
Claim 2
Dependent Claim
269 words
A cell for a charge-coupled device comprising: a semiconductor substrate; an insulation layer formed above said substrate; and an electrode formed above said insulation layer; the substrate including a channel region of length coextensive with said electrode in one lateral direction for conducting charge carriers under said electrode, the channel region comprising a barrier portion of substantial and continuous dimension in said lateral direction having a substantially homogeneous first built-in potential in said lateral direction providing minimal electric field in said lateral direction, the channel region further comprising a well portion of continuous dimension in said lateral direction and extending across 30% to 70% of the portion of the channel region in said lateral direction not included in said barrier portion, said well portion having a substantially homogeneous built-in second potential in said lateral direction providing minimal electric field in said lateral direction, and the channel region further comprising a trench portion at continuous dimension in said lateral direction and extending across 70% to 30% of the portion of the channel region in said lateral direction not included in said barrier portion, said well portion having a substantially homogeneous built-in third potential in said lateral direction providing minimal electric field in said lateral direction, said barrier, well and trench portions being respectively aligned in said lateral direction, said first and second potentials differing so as to provide a first electrical field between said barrier and well portions driving carriers in said lateral direction, said second and third potentials differing so as to provide a second electrical field between said well and trench portions driving carriers in said lateral direction.
Claim 3
Dependent Claim
31 words
The cell in accordance with claim 1 wherein a first potential difference between said first and second potentials is larger than a second potential difference between said second and third potentials.
Claim 4
Dependent Claim
32 words
The cell in accordance with claim 1 wherein a first potential difference between said second and third potentials is 20-50% of a second potential difference between said first and and third potentials.
Claim 5
Dependent Claim
49 words
The cell in accordance with claim 1 wherein said barrier, well and trench portions of said channel region each have substantially uniform dopant concentrations throughout substantially all of their lengths in said lateral direction, and wherein dopant concentrations of said barrier, well and trench portions differ one from another.
Claim 6
Dependent Claim
21 words
The cell in accordance with claim 1 wherein said channel region conducts said carriers substantially below a surface of said substrate.
Claim 7
Dependent Claim
47 words
The cell in accordance with claim 1 wherein a portion of said insulation layer has a stepped thickness in said lateral direction, said insulation layer being thicker over said trench portion than over said well portion and thicker over said well portion than over said barrier portion.
Claim 8
Dependent Claim
19 words
The cell in accordance with claim 1 wherein said electrode has a stepped work function in said lateral direction.
Claim 9
Dependent Claim
143 words
A cell for a charge-coupled device comprising: an intrinsic p-type semiconductor substrate including a doped n-type channel region; an insulation layer formed above said substrate; and an electrode formed above said insulation layer; the channel region being of length coextensive with said electrode in one lateral direction for conducting electrons in said lateral direction, the channel region comprising barrier, well and trench portions respectively aligned in said lateral direction, the well portion extending across at least 30% of remaining portion of the channel region in said lateral direction not included in said barrier portion, the trench portion extending across at least 30% of said remaining portion of said channel region, the barrier, well and trench portions each having a substantially uniform dopant concentration in said lateral direction, the uniform dopant concentrations of said barrier, well and trench portions substantially differing one from another.
Claim 10
Dependent Claim
143 words
A cell for a charge-coupled device comprising: an intrinsic p-type semiconductor substrate including a doped n-type channel region; an insulation layer formed above said substrate; and an electrode formed above said insulation layer; the channel region being of length coextensive with said electrode in one lateral direction for conducting electrons in said lateral direction, the channel region comprising barrier, well and trench portions respectively aligned in said lateral direction, the well portion extending across at least 30% of remaining portion of the channel region in said lateral direction not included in said barrier portion, the trench portion extending across at least 30% of said remaining portion of said channel region, the barrier, well and trench portions each having a substantially uniform dopant concentration in said lateral direction, the uniform dopant concentrations of said barrier, well and trench portions substantially differing one from another.
Claim 11
Dependent Claim
34 words
The cell in accordance with claim 8 wherein a first potential difference between built-in potentials of said barrier and well portions is larger than a second potential difference between said well and trench portions.
Claim 12
Dependent Claim
19 words
The cell in accordance with claim 9 wherein said first potential difference is 20-50% of said second potential difference.
Claim 13
Independent Claim
125 words
A method of fabricating a charge-coupled device cell comprising: forming an insulation layer above a semiconductor substrate; depositing a first conductive layer on said insulation layer; removing a portion of said first conductive layer to expose a portion of said insulation layer; doping said semiconductor substrate below said exposed portion of said insulation layer with first dopant ions; covering 30-70% of said exposed portion of said insulation layer along one lateral dimension with a mask layer positioned laterally adjacent to said first conductive layer; doping said semiconductor substrate with second dopant ions where not covered by said first conductive layer or said mask layer; removing said mask layer from said insulation layer; and forming a second conductive layer on exposed portions of said insulation layer.
Claim 14
Independent Claim
125 words
A method of fabricating a charge-coupled device cell comprising: forming an insulation layer above a semiconductor substrate; depositing a first conductive layer on said insulation layer; removing a portion of said first conductive layer to expose a portion of said insulation layer; doping said semiconductor substrate below said exposed portion of said insulation layer with first dopant ions; covering 30-70% of said exposed portion of said insulation layer along one lateral dimension with a mask layer positioned laterally adjacent to said first conductive layer; doping said semiconductor substrate with second dopant ions where not covered by said first conductive layer or said mask layer; removing said mask layer from said insulation layer; and forming a second conductive layer on exposed portions of said insulation layer.
Claim 15
Dependent Claim
22 words
The method in accordance with claim 11 further comprising the step of connecting a conductor between said first and second conductive layers.
Claim 16
Dependent Claim
27 words
The method in accordance with claim 11 wherein said substrate consists of intrinsic p-type semiconductor material and wherein said first and second dopant ions are positively charged.
Claim 17
Independent Claim
149 words
A method of fabricating a charge-coupled device cell comprising: forming an insulation layer above a p-type semiconductor substrate; doping said semiconductor substrate with positive dopant ions to create an n-type channel region in said semiconductor substrate under said insulation layer; depositing a first conductive layer on said insulation layer; removing a portion of said first conductive layer to expose a portion of said insulation layer; doping said semiconductor substrate under the exposed portion of said insulation layer with additional positive dopant ions; covering 30-70% of a lateral dimension of said exposed portion of said insulation layer laterally adjacent to said first conductive layer with a mask layer; doping said semiconductor substrate where not covered by said first conductive layer or said mask layer with additional positive dopant ions; removing said mask layer from said insulation layer; and forming a second conductive layer on exposed portions of said insulation layer.
Claim 18
Independent Claim
149 words
A method of fabricating a charge-coupled device cell comprising: forming an insulation layer above a p-type semiconductor substrate; doping said semiconductor substrate with positive dopant ions to create an n-type channel region in said semiconductor substrate under said insulation layer; depositing a first conductive layer on said insulation layer; removing a portion of said first conductive layer to expose a portion of said insulation layer; doping said semiconductor substrate under the exposed portion of said insulation layer with additional positive dopant ions; covering 30-70% of a lateral dimension of said exposed portion of said insulation layer laterally adjacent to said first conductive layer with a mask layer; doping said semiconductor substrate where not covered by said first conductive layer or said mask layer with additional positive dopant ions; removing said mask layer from said insulation layer; and forming a second conductive layer on exposed portions of said insulation layer.
Claim 19
Dependent Claim
22 words
The method in accordance with claim 14 further comprising the step of connecting a conductor between said first and second electrode layers.
References Cited (Backward Citations)
No citation records indexed.
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