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US5240873A
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Method of making charge transfer device
Assignee: Intellectual Ventures II LLC
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Filing: 1992-09-14
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Granted: 1993-08-31
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Expires: 2012-09-14
Abstract
Abstract A method of making a charge transfer device, capable of forming a plurality of transfer electrodes, using a single conductive layer, with a narrow transfer electrode gap enough to achieve a high transfer efficiency. The method comprises forming an impurity layer of a second conductivity type, a first insulating layer and a semiconductor layer in this order, over a first conductivity type semiconductor substrate, forming spaced semiconductor layer patterns, forming a second insulating layer over the resultant entire exposed surface and implanting impurity ions of the first conductivity type in the second conductivity type impurity layer so as to form spaced impurity layers of the first conductivity type, and forming a third insulating layer over the resultant entire exposed surface and etching back the third insulating layer to the semiconductor layer patterns. After removing the semiconductor layer patterns and the remaining third insulating layer, a conductive layer and a fourth insulating layer are formed over the entire surface of the remaining second insulating layer. Thereafter, the fourth insulating layer, the conductive layer and the second insulating layer are etched back, so as to form separate conductive layer patterns as transfer electrodes.
Inventors
- 👤 Uya Shinji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:47
CPC Classifications
H; H10; H10D; H10D44/00; H10D44/01; H10D44/041; H10D44/40; H10D44/45; H10D44/462; H10D44/464
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
256 words
A method of making a charge transfer device comprising the steps of: preparing a semiconductor substrate of a first conductivity type; forming an impurity layer of a second conductivity type, a first insulating layer and a semiconductor layer in this order, over the first conductivity type semiconductor substrate; patterning the semiconductor layer so as to form uniformly spaced semiconductor layer patterns; forming a second insulating layer over the resultant entire exposed surface after the formation of the semiconductor layer patterns and implanting impurity ions of the first conductivity type in the second conductivity type impurity layer so as to form uniformly spaced impurity layers of the first conductivity type; forming a third insulating layer for providing a surface smoothness over the resultant entire exposed surface after the formation of the first conductivity type impurity layers and etching back the third insulating layer to the upper surfaces of the semiconductor layer patterns; removing the semiconductor layer patterns and the remaining portions of the third insulating layer; forming a conductive layer and a fourth insulating layer for providing a surface smoothness in this order, over the entire surface of the remaining second insulating layer; etching back the resultant upper portion after the formation of the fourth insulating layer uniformly, so as to form a plurality of separate conductive layer patterns as transfer electrodes; removing the remaining portions of the fourth insulating layer disposed over respective conductive layer patterns; and forming a fifth insulating layer over the resultant entire exposed surface after the removal of the fourth insulating layer.
Claim 2
Independent Claim
256 words
A method of making a charge transfer device comprising the steps of: preparing a semiconductor substrate of a first conductivity type; forming an impurity layer of a second conductivity type, a first insulating layer and a semiconductor layer in this order, over the first conductivity type semiconductor substrate; patterning the semiconductor layer so as to form uniformly spaced semiconductor layer patterns; forming a second insulating layer over the resultant entire exposed surface after the formation of the semiconductor layer patterns and implanting impurity ions of the first conductivity type in the second conductivity type impurity layer so as to form uniformly spaced impurity layers of the first conductivity type; forming a third insulating layer for providing a surface smoothness over the resultant entire exposed surface after the formation of the first conductivity type impurity layers and etching back the third insulating layer to the upper surfaces of the semiconductor layer patterns; removing the semiconductor layer patterns and the remaining portions of the third insulating layer; forming a conductive layer and a fourth insulating layer for providing a surface smoothness in this order, over the entire surface of the remaining second insulating layer; etching back the resultant upper portion after the formation of the fourth insulating layer uniformly, so as to form a plurality of separate conductive layer patterns as transfer electrodes; removing the remaining portions of the fourth insulating layer disposed over respective conductive layer patterns; and forming a fifth insulating layer over the resultant entire exposed surface after the removal of the fourth insulating layer.
Claim 3
Dependent Claim
65 words
A method of making a charge transfer device, in accordance with claim 1, wherein the step of forming the second conductivity type impurity layer comprises the steps of: implanting impurity ions of the second conductivity type in the surface of the first conductivity type semiconductor substrate; and diffusing the second conductivity type impurity ions to a predetermined depth in the first conductivity type semiconductor substrate.
Claim 4
Dependent Claim
65 words
A method of making a charge transfer device, in accordance with claim 1, wherein the step of forming the second conductivity type impurity layer comprises the steps of forming another semiconductor layer over the first conductivity type semiconductor substrate; and implanting impurity ions of the second conductivity type in the surface of the another semiconductor layer, simultaneously with the formation of the another semiconductor layer.
Claim 5
Dependent Claim
20 words
A method of making a charge transfer device, in accordance with claim 1, wherein the semiconductor layer comprises polycrystalline silicon.
Claim 6
Dependent Claim
57 words
A method of making a charge transfer device, in accordance with claim 1, further comprising the step of dry etching the exposed portions of the first insulating layer using the semiconductor layer patterns as a mask prior to the formation of the second insulating layer, so as to remove the exposed portions of the first insulating layer.
Claim 7
Dependent Claim
40 words
A method of making a charge transfer device, in accordance with claim 1, wherein the formations of the first and second insulating layers are achieved by thermally oxidizing the first conductivity type semiconductor substrate and each semiconductor layer pattern, respectively.
Claim 8
Dependent Claim
33 words
A method of making a charge transfer device, in accordance with claim 1, wherein the third to fifth insulating layers comprise either a boron phosphorous silicate glass, a spin-on glass or a photoresist.
Claim 9
Dependent Claim
35 words
A method of making a charge transfer device, in accordance with claim 1, wherein each of the semiconductor layer patterns has side surfaces extending perpendicularly to the surface of the first conductivity type semiconductor substrate.
Claim 10
Dependent Claim
33 words
A method of making a charge transfer device, in accordance with claim 1, wherein the conductive layer comprises either a metal, a transparent electrode material or a semiconductor material doped with an impurity.
Claim 11
Dependent Claim
22 words
A method of making a charge transfer device, in accordance with claim 9, wherein the metal is one of aluminum and tungsten.
Claim 12
Dependent Claim
23 words
A method of making a charge transfer device, in accordance with claim 9, wherein the transparent electrode material is an indium tin oxide.
Claim 13
Dependent Claim
20 words
A method of making a charge transfer device, in accordance with claim 9, wherein the semiconductor material is polycrystalline silicon.
Claim 14
Independent Claim
265 words
A method of making a charge transfer device comprising the steps of: preparing a semiconductor substrate of a first conductivity type; forming an impurity layer of a second conductivity type, a first insulating layer and a semiconductor layer in this order, over the first conductivity type semiconductor substrate; patterning the semiconductor layer so as to form uniformly spaced semiconductor layer patterns; forming a second insulating layer over the resultant entire exposed surface after the formation of the semiconductor layer patterns and implanting impurity ions of the first conductivity type in the second conductivity type impurity layer so as to form uniformly spaced impurity layers of the first conductivity type; forming a third insulating layer for providing a surface smoothness over the resultant entire exposed surface after the formation of the first conductivity type impurity layers and etching back the third insulating layer to the upper surfaces of the semiconductor layer patterns; removing the semiconductor layer patterns and the remaining portions of the third insulating layer; forming a conductive layer and a fourth insulating layer for providing a surface smoothness in this order, over the entire surface of the remaining second insulating layer; etching back the fourth insulating layer until each upper portion of the conductive layer is partially exposed; removing partially each exposed upper portion of the conductive layer so as to form a plurality of separate conductive layer patterns; removing the remaining portions of the fourth insulating layer disposed over respective conductive layer patterns; and forming a fifth insulating layer over the resultant entire exposed surface after the removal of the fourth insulating layer.
Claim 15
Independent Claim
265 words
A method of making a charge transfer device comprising the steps of: preparing a semiconductor substrate of a first conductivity type; forming an impurity layer of a second conductivity type, a first insulating layer and a semiconductor layer in this order, over the first conductivity type semiconductor substrate; patterning the semiconductor layer so as to form uniformly spaced semiconductor layer patterns; forming a second insulating layer over the resultant entire exposed surface after the formation of the semiconductor layer patterns and implanting impurity ions of the first conductivity type in the second conductivity type impurity layer so as to form uniformly spaced impurity layers of the first conductivity type; forming a third insulating layer for providing a surface smoothness over the resultant entire exposed surface after the formation of the first conductivity type impurity layers and etching back the third insulating layer to the upper surfaces of the semiconductor layer patterns; removing the semiconductor layer patterns and the remaining portions of the third insulating layer; forming a conductive layer and a fourth insulating layer for providing a surface smoothness in this order, over the entire surface of the remaining second insulating layer; etching back the fourth insulating layer until each upper portion of the conductive layer is partially exposed; removing partially each exposed upper portion of the conductive layer so as to form a plurality of separate conductive layer patterns; removing the remaining portions of the fourth insulating layer disposed over respective conductive layer patterns; and forming a fifth insulating layer over the resultant entire exposed surface after the removal of the fourth insulating layer.
Claim 16
Dependent Claim
65 words
A method of making a charge transfer device, in accordance with claim 13, wherein the step of forming the second conductivity type impurity layer comprises the steps /f: implanting impurity ions of the second conductivity type in the surface of the first conductivity type semiconductor substrate; and diffusing the second conductivity type impurity ions to a predetermined depth in the first conductivity type semiconductor substrate.
Claim 17
Dependent Claim
65 words
A method of making a charge transfer device, in accordance with claim 13, wherein the step of forming the second conductivity type impurity layer comprises the steps of forming another semiconductor layer over the first conductivity type semiconductor substrate; and implanting impurity ions of the second conductivity type in the surface of the another semiconductor layer, simultaneously with the formation of the another semiconductor layer.
Claim 18
Dependent Claim
20 words
A method of making a charge transfer device, in accordance with claim 13, wherein the semiconductor layer comprises polycrystalline silicon.
Claim 19
Dependent Claim
57 words
A method of making a charge transfer device, in accordance with claim 13, further comprising the step of dry etching the exposed portions of the first insulating layer using the semiconductor layer patterns as a mask prior to the formation of the second insulating layer, so as to remove the exposed portions of the first insulating layer.
Claim 20
Dependent Claim
40 words
A method of making a charge transfer device, in accordance with claim 13, wherein the formations of the first and second insulating layers are achieved by thermally oxidizing the first conductivity type semiconductor substrate and each semiconductor layer pattern, respectively.
Claim 21
Dependent Claim
33 words
A method of making a charge transfer device, in accordance with claim 13, wherein the third to fifth insulating layers comprise either a boron phosphorous silicate glass, a spin-on glass or a photoresist.
Claim 22
Dependent Claim
35 words
A method of making a charge transfer device, in accordance with claim 13, wherein each of the semiconductor layer patterns has side surfaces extending perpendicularly to the surface of the first conductivity type semiconductor substrate.
Claim 23
Dependent Claim
33 words
A method of making a charge transfer device, in accordance with claim 13, wherein the conductive layer comprises either a metal, a transparent electrode material or a semiconductor material doped with an impurity.
Claim 24
Dependent Claim
22 words
A method of making a charge transfer device, in accordance with claim 21, wherein the metal is one of aluminum and tungsten.
Claim 25
Dependent Claim
23 words
A method of making a charge transfer device, in accordance with claim 21, wherein the transparent electrode material is an indium tin oxide.
Claim 26
Dependent Claim
20 words
A method of making a charge transfer device, in accordance with claim 21, wherein the semiconductor material is polycrystalline silicon.
Claim 27
Dependent Claim
34 words
A method of making a charge transfer device, in accordance with claim 13, wherein the step of removing partially each exposed upper portion of the conductive layer is achieved by a wet etching method.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-08-30 | 1997-03-01 | 1997-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-08-30 | 2001-03-01 | 2001-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-08-30 | 2005-03-01 | 2005-08-31 | $7700.00 | Window Closed / Lapsed |