EP0387892A2 — Forming an insulation layer, for example in an ac…

Claim 1

Independent Claim 116 words

A method of forming an insulation layer on a substrate, the method comprising the following steps:- (a) Subjecting the substrate to the vapour of a metal compound, organic or inorganic, which can react with H₂O and/or O₂ to form metal oxide, for a period of time sufficient for the formation of less than or substantially a single atomic layer of metal compound, and (b) Subjecting the surface of the thus formed metal compound layer to H₂O vapour and/or O₂ gas for a period of time sufficient for the metal compound layer to be replaced by a layer of metal oxide; steps (a) and (b) being repeated until the insulation layer thus formed reaches a desired thickness.

Claim 2

Independent Claim 116 words

A method of forming an insulation layer on a substrate, the method comprising the following steps:- (a) Subjecting the substrate to the vapour of a metal compound, organic or inorganic, which can react with H₂O and/or O₂ to form metal oxide, for a period of time sufficient for the formation of less than or substantially a single atomic layer of metal compound, and (b) Subjecting the surface of the thus formed metal compound layer to H₂O vapour and/or O₂ gas for a period of time sufficient for the metal compound layer to be replaced by a layer of metal oxide; steps (a) and (b) being repeated until the insulation layer thus formed reaches a desired thickness.

Claim 3

Dependent Claim 122 words

A method as claimed in claim 1, further comprising the following steps:- (c) Subjecting the substrate to the vapour of a further metal compound, organic or inorganic, which can react with H₂O and/or O₂ to form further metal oxide, for a period of time sufficient for the formation of less than or substantially a single atomic layer of further metal compound, and (d) Subjecting the surface of the further metal compound layer formed in step (c) to H₂O vapour and/or O₂ gas for a period of time sufficient for the further metal compound layer to be replaced by a layer of further metal oxide; steps (a), (b), (c) and (d) being repeated until the insulation layer thus formed reaches a desired thickness.

Claim 4

Dependent Claim 39 words

A method as claimed in claim 1 or 2, wherein steps (a) and (b), and steps (c) and (d) when employed, are performed under conditions such that the vapour and/or gas involved is in a state of molecular flow.

Claim 5

Dependent Claim 29 words

A method as claimed in claim 3, wherein a vapour and/or gas pressure in the range one to several tens of milliTorr is employed to achieve the said conditions.

Claim 6

Dependent Claim 69 words

A method as claimed in claim 1, 2, 3 or 4, wherein the metal compound used in step (a) is selected either from:- (i) aluminium chloride, aluminium bromide, trimethylaluminium, triethylaluminium, dimethylaluminiumchloride,diethylaluminium chloride, in a case in which the metal oxide provided in step (b) is aluminium oxide; or from:- (ii) titanium chloride, titanium bromide, in a case in which the metal oxide provided in step (b) is titanium oxide.

Claim 7

Independent Claim 45 words

A method of forming a thin film transistor on a substrate, the transistor comprising a gate electrode, a gate insulation layer, a semiconductor layer, and source and drain electrodes, wherein the gate insulation layer is formed by a method as claimed in any preceding claim.

Claim 8

Dependent Claim 76 words

A method as claimed in claim 6, wherein the thin film transistor comprises a further gate insulation layer, of silicon nitride, deposited on the gate insulation layer of claim 6 by a plasma CVD method, and wherein the semiconductor layer is an amorphous silicon semiconductor layer which is deposited on the further gate insulation layer by the plasma CVD method, using the same apparatus as is used for the deposition of the further gate insulation layer.

Claim 9

Independent Claim 75 words

A method of manufacturing an active matrix display device, employing a method of forming an insulation layer as claimed in any one of claims 1 to 5, wherein the so formed insulation layer in the active matrix display device functions in the device as a gate insulation layer of a thin film transistor, or an inter-busline insulation layer, or a protective layer on a thin film transistor, or an insulation layer of an auxiliary capacitor.

Claim 10

Dependent Claim 128 words

A method as claimed in claim 8, wherein the active matrix display device has first and second substrates forming an enclosure, a plurality of display elements arranged in rows and columns, each display element comprising first and second transparent electrodes formed on inside surfaces of the first and second substrates respectively and light influencing material therebetween, a plurality of thin film transistors formed on the first substrate at positions corresponding to those of the display elements and having each a gate electrode, a gate insulation layer, a semiconductor layer, and source and drain electrodes, and at least gate bus lines formed on the first substrate for driving the display elements through the thin film transistors, the gate bus line connecting the gate electrodes located in the row direction.

Claim 11

Dependent Claim 23 words

A method as claimed in claim 9, wherein the so formed insulation layer is a gate insulation layer of a thin film transistor.

Claim 12

Dependent Claim 36 words

A method as claimed in claim 9 or 10, wherein the active matrix display device further comprises source/drain bus lines connecting a plurality of source/drain electrodes in the column direction and formed on the first substrate.

Claim 13

Dependent Claim 46 words

A method as claimed in claim 9, 10 or 11 further comprising:- forming the gate electrode of conductive material on the first substrate before forming said gate insulation layer; and depositing an amorphous silicon semiconductor layer on said gate insulation layer by a plasma CVD method.

Claim 14

Dependent Claim 32 words

A method as claimed in claim 9, 10, 11 or 12, further comprising:- depositing a second gate insulation layer of silicon nitride on said gate insulation layer by a plasma CVD method.

Claim 15

Dependent Claim 65 words

A method as claimed in claim 9, the device further comprising source/drain bus lines formed on the first substrate, the source/drain bus lines connecting source/drain electrodes in the column direction and the gate and source/drain bus lines being insulated from each other by an inter-bus line insulation layer at each intersection of such lines, wherein the so formed insulation layer is an inter-busline insulation layer.

Claim 16

Dependent Claim 36 words

A method as claimed in claim 14, wherein a second inter-busline insulation layer of silicon nitride is deposited by a plasma CVD method on the so formed insulation layer before the source/drain bus lines are formed.

Claim 17

Dependent Claim 27 words

A method as claimed in claim 14 or 15, wherein the so formed insulation layer serves as an inter-busline insulation layer and as a gate insulation layer.

Claim 18

Dependent Claim 34 words

A method as claimed in claim 9, the device further comprising a protection layer, at least on a thin film transistor region of the device, wherein the so formed layer is the protection layer.

Claim 19

Dependent Claim 77 words

A method as claimed in claim 9, the display device further comprising auxiliary capacitors, corresponding to respective display elements, each formed by a first transparent electrode and another auxiliary electrode formed on the first substrate, having a capacitor insulation layer therebetween, the method comprising forming the auxiliary electrode on the first substrate; providing the so formed insulation layer as the capacitor insulation on the auxiliary electrode; and forming the first transparent electrode on the capacitor insulation layer.

Claim 20

Dependent Claim 177 words

An active matrix display device comprising first and second substrates forming an enclosure, a plurality of display elements arranged in rows and columns, each display element comprising first and second transparent electrodes formed on inside surfaces of the first and second substrates respectively and light influencing material therebetween, a plurality of thin film transistors formed on the first substrate, said thin film transistors being positioned to correspond to display elements, and first and second groups of bus lines selectively formed on the substrates and insulated from each other for driving the display elements through said thin film transistors, each said thin film transistor comprising:- a gate electrode; a gate insulation layer comprising a first insulation layer on the gate electrode and a second insulation layer on the first insulation layer, the first insulation layer being of aluminium oxide formed by ALE deposition, and the second insulation layer being of silicon nitride formed by plasma CVD; an amorphous silicon layer on the second insulation layer by plasma CVD; and source and drain electrodes on the amorphous silicon layer.

Claim 21

Dependent Claim 177 words

An active matrix display device comprising first and second substrates forming an enclosure, a plurality of display elements arranged in rows and columns, each display element comprising first and second transparent electrodes formed on inside surfaces of the first and second substrates respectively and light influencing material therebetween, a plurality of thin film transistors formed on the first substrate, said thin film transistors being positioned to correspond to display elements, and first and second groups of bus lines selectively formed on the substrates and insulated from each other for driving the display elements through said thin film transistors, each said thin film transistor comprising:- a gate electrode; a gate insulation layer comprising a first insulation layer on the gate electrode and a second insulation layer on the first insulation layer, the first insulation layer being of aluminium oxide formed by ALE deposition, and the second insulation layer being of silicon nitride formed by plasma CVD; an amorphous silicon layer on the second insulation layer by plasma CVD; and source and drain electrodes on the amorphous silicon layer.

Forming an insulation layer, for example in an active matrix device

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag