EP0185995A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Programmable semiconductor switch for a light influencing display and method of making same
Assignee: Energy Conversion Devices Inc
•
Filing: 1985-12-05
•
Granted: —
•
Expires: 2005-12-05
Abstract
Abstract A method of forming a pixel for a liquid crystal display includes forming a pixel electrode (24) on a substrate (15), depositing a continuous three layer amorphous silicon alloy structure with an intrinsic layer (68) between two n-doped layers (66;70), depositing an opaque metal layer (64) over the semiconductor layers and etching the top metal layer and semiconductor layers to form continuous address lines (32) with underlying semiconductor layers and a bidirectional threshold element (60) connected between each electrode and an adjacent overlying address line. A metal pad (62) positioned on each electrode provides for improved conductivity with each adjacent threshold element. The threshold elements have a threshold settable by directing light through each pad, provided the pads are at least partly transmissive. A symmetrical bidirectional threshold element (140) is formed of first and second series coupled threshold elements (150; 152).
Inventors
- 👤 Willem Ph.D. Physics Den Boer
- 👤 Zvi Ph.D. Physics Yaniv
- 👤 J. Scott Payson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 05:34
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/135; G02F1/1354; G02F1/136; G02F1/1362; G02F1/1365; H; H10; H10D; H10D1/00; H10D1/40; H10W; H10W20/00; H10W20/40; H10W20/49
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
191 words
A method of forming a subassembly (10) for use in a light influencing display characterized by: (A) providing a insulative substrate (15); (B) forming a conductor (24, 62), having at least two conductive layers, of a selected size and shape over said substrate with an overlying first doped semiconductor layer (66); (C) forming a multilayer structure by: (a) depositing a substantially intrinsic semiconductor layer (68) over at least said first doped layer; (b) depositing a second doped semiconductor layer (70) over said intrinsic layer; and (c) depositing a metal layer (64) over said second doped layer; (D) selectively removing at least portions of said multilayer structure to form a threshold device (60) overlying at least part of said conductor and an address line (32) with said threshold device coupled between said conductor and said address line, said address line including a shaped region of said metal layer overlying a corresponding shaped region of at least said semiconductor layers deposited during step (c); and (E) removing at least portions of one of the layers in said conductor so as to expose at least a part of the other layer of said conductor.
Claim 2
Independent Claim
191 words
A method of forming a subassembly (10) for use in a light influencing display characterized by: (A) providing a insulative substrate (15); (B) forming a conductor (24, 62), having at least two conductive layers, of a selected size and shape over said substrate with an overlying first doped semiconductor layer (66); (C) forming a multilayer structure by: (a) depositing a substantially intrinsic semiconductor layer (68) over at least said first doped layer; (b) depositing a second doped semiconductor layer (70) over said intrinsic layer; and (c) depositing a metal layer (64) over said second doped layer; (D) selectively removing at least portions of said multilayer structure to form a threshold device (60) overlying at least part of said conductor and an address line (32) with said threshold device coupled between said conductor and said address line, said address line including a shaped region of said metal layer overlying a corresponding shaped region of at least said semiconductor layers deposited during step (c); and (E) removing at least portions of one of the layers in said conductor so as to expose at least a part of the other layer of said conductor.
Claim 3
Dependent Claim
69 words
A method as defined in claim 1 wherein step (3) includes: (a) depositing the first conductive layer (24) over a selected surface of said substrate; (b) depositing the second conductive layer (62) over said first conductive layer; (c) removing portions of said conductive layers to form said conductor of a selected size and shape; and (d) depositing said first doped semiconductor layer (66) over said conductor and said substrate.
Claim 4
Dependent Claim
22 words
A method as defined in claim 2 including: exposing said threshold device (60) to selected radiant energy to adjust the threshold thereof.
Claim 5
Dependent Claim
21 words
A method as defined in claim 2 wherein step (B)(a) is performed by depositing a transparent conductive layer over said substrate.
Claim 6
Dependent Claim
33 words
A method as defined in claim 3 wherein the second conductive layer of step (B)(b) is a metal and step (B)(b) is performed by depositing the metal layer (62) to a selected thickness.
Claim 7
Dependent Claim
22 words
A method as defined in claim 4 wherein said thickness is selected so as to permit the passage of radiant energy therethrough.
Claim 8
Dependent Claim
45 words
A method as defined in claim 2 wherein said first semiconductor layer of step (B)(d) and said multilayer structure of step (C) are formed in a partial vacuum and wherein said partial vacuum is continuously maintained during the performance of steps (B)(d), (C)(a), and (C)(b).
Claim 9
Dependent Claim
23 words
A method as defined in claim 7 wherein said semiconductor layers are deposited as an amorphous semiconductor alloy which includes silicon and germanium.
Claim 10
Dependent Claim
22 words
A method as defined in claim 8 wherein said metal layer is formed of chromium or an alloy of molybdenum and tantalum.
Claim 11
Dependent Claim
22 words
A method as defined in claim 7 wherein step (D) includes removing said portions of said multilayer structure in one continuous process.
Claim 12
Dependent Claim
12 words
A method as defined in claim 10 wherein step (D) includes etching.
Claim 13
Dependent Claim
14 words
A method as defined in claim 3 wherein said radiant energy is visible light.
Claim 14
Dependent Claim
77 words
A method as defined in claim 1 wherein step (B) includes: (a) depositing the first conductive layer (24) over a selected surface of said substrate; (b) depositing the second conductive layer (62) over said first conductive layer; (c) depositing said first doped semiconductor layer (66) over said second conductive layer; and (d) removing portions of said semiconductor layer and said conductive layers to form said conductor of a selected size and shape with said overlying semiconductor layer.
Claim 15
Dependent Claim
34 words
A method as defined in claim 13 wherein step (E) includes: removing portions of said first doped semiconductor layer and said second conductive layer so as to expose part of said first conductive layer.
Claim 16
Dependent Claim
21 words
A method as defined in claim 14 wherein step (B)(a) is performed by depositing a transparent conductive layer over said substrate.
Claim 17
Dependent Claim
38 words
A method as defined in claim 13 wherein said multilayer structure of step (C) is formed in a partial vacuum and wherein said partial vacuum is continuously maintained during the performance of at least steps (C)(a) and (C)(b).
Claim 18
Dependent Claim
23 words
A method as defined in claim 16 wherein said semiconductor layers are deposited as an amorphous semiconductor alloy which includes silicon or germanium.
Claim 19
Dependent Claim
21 words
A method as defined in claim 17 wherein said metal is formed of chromium or an alloy of molybdenum and tantalum.
Claim 20
Dependent Claim
22 words
A method as defined in claim 13 wherein step (D) includes removing said portions of said multilayer structure in one continuous process.
Claim 21
Dependent Claim
12 words
A method as defined in claim 19 wherein step (D) includes etching.
Claim 22
Dependent Claim
53 words
A pixel for a display characterized by: an insulative substrate (15); a pixel electrode (24) formed on said substrate; multilayer threshold means (60) for isolation coupled to said electrode, said threshold means having a threshold settable in response to selected radiation incident thereon; and a radiation blocking address line overlying said threshold means.
Claim 23
Dependent Claim
53 words
A pixel for a display characterized by: an insulative substrate (15); a pixel electrode (24) formed on said substrate; multilayer threshold means (60) for isolation coupled to said electrode, said threshold means having a threshold settable in response to selected radiation incident thereon; and a radiation blocking address line overlying said threshold means.
Claim 24
Dependent Claim
44 words
A pixel as defined in claim 21 wherein said substrate is transparent and said threshold means includes a surface at least partly transmissive to incident radiation with said threshold settable in response to radiant energy directed through said substrate and into said threshold means.
Claim 25
Dependent Claim
30 words
A pixel as defined in claim 21 wherein said multilayer threshold means and address line extend continuously between at least said pixel electrode and a second, spaced apart pixel electrode.
Claim 26
Dependent Claim
33 words
A pixel as defined in claim 23 wherein said multilayer threshold means includes at least a first layer (68) formed of semiconductor material and a second overlying layer (64) formed of a metal.
Claim 27
Dependent Claim
16 words
A pixel as defined in claim 24 wherein said semiconductor material is a deposited semiconductor material.
Claim 28
Dependent Claim
30 words
A pixel as defined in claim 25 wherein said deposited semiconductor material is an amorphous semiconductor alloy including a semiconductor element selected from the group consisting of silicon and germanium.
Claim 29
Dependent Claim
17 words
A pixel as defined in claim 21 wherein said electrode is formed from a transparent conductive material.
Claim 30
Dependent Claim
87 words
In a subassembly (130) for use in a light influencing display having a substrate (132) with both a display electrode (136) and an adjacent address line (134) formed thereon, the improvement characterized by: first and second bidirectional means (150;152) for forming a threshold, said first and second threshold means being coupled between said electrode and said address line so as to form a bidirectional symmetrical threshold element (140) therebetween, with one of said threshold means being formed at least partly overlying said electrode or said address line.
Claim 31
Dependent Claim
87 words
In a subassembly (130) for use in a light influencing display having a substrate (132) with both a display electrode (136) and an adjacent address line (134) formed thereon, the improvement characterized by: first and second bidirectional means (150;152) for forming a threshold, said first and second threshold means being coupled between said electrode and said address line so as to form a bidirectional symmetrical threshold element (140) therebetween, with one of said threshold means being formed at least partly overlying said electrode or said address line.
Claim 32
Dependent Claim
18 words
A subassembly as defined in claim 28 wherein said first and said second threshold means are parallel coupled.
Claim 33
Dependent Claim
18 words
A subassembly as defined in claim 28 wherein said first and said second threshold means are series coupled.
Claim 34
Dependent Claim
23 words
A subassembly as defined in claim 28 wherein: said first and second threshold means are formed of multilayer semiconductor material (142, 144, 146).
Claim 35
Dependent Claim
43 words
A subassembly as defined in claim 31 wherein: said first and second threshold means are each formed of a first doped layer (142) of semiconductor material, an overlying layer (144) of intrinsic semiconductor material and a second doped layer (146) of semiconductor material.
Claim 36
Dependent Claim
28 words
A subassembly as defined in claim 32 wherein: said second doped layers of semiconductor material of said two threshold devices are coupled by a layer (148) of metal.
Claim 37
Dependent Claim
21 words
A subassembly as defined in claim 33 wherein: said first threshold means (150) overlies a region of said address line (134).
Claim 38
Dependent Claim
18 words
A subassembly as defined in claim 34 wherein each said layer of semiconductor material is deposited semiconductor material.
Claim 39
Dependent Claim
22 words
A subassembly as defined in claim 35 wherein each said layer of deposited semiconductor material is a layer of amorphous semiconductor alloy.
Claim 40
Dependent Claim
25 words
A subassembly as defined in claim 36 wherein said amorphous semiconductor alloy includes a semiconductor element selected from the group consisting of silicon and germanium.
Claim 41
Dependent Claim
21 words
A subassembly as defined in claim 32 wherein each said doped semiconductor alloy layer includes dopants of the same conductivity type.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.