DE102007023803A1 - Preparing layer systems, useful in an article, comprises applying a layer system with two layers on an article, an intermediate layer between the layers and an organic and inorganic precursors into the coating- or reaction chamber - Google Patents

Abstract

Preparing layer systems, comprises applying a layer system with at least two layers on an article, applying at least an intermediate layer between the layers, applying an organic and an inorganic precursors simultaneously and/or successively into the coating- or reaction chamber for applying the intermediate layer and applying the organic and inorganic precursors essentially simultaneously for the reaction and/or separation. An independent claim is included for an article comprising an interference-optical layer system or a layer system with at least two layers and at least one intermediate layer between the layers, produced by the above process.

Description

The This invention relates generally to methods for making layer systems with intermediate layers and a preferably prepared according to the method Object with at least one layer system, which one or contains several intermediate layers.

interlayers in conventional layer systems have already been used to influence the morphology of the shift system.

In the PCT / EP03 / 10221 describes methods and arrangements for the production of protective layers, in which a protective layer for a body which comprises at least one hard material layer of a metal oxide and / or metal nitride and / or metal carbide and / or metal oxonitride and / or metal carbonitride and / or metal oxocarbonitride, on a body is applied and in which this protective layer comprises a functional layer which is interrupted by at least one, different from the functional layer intermediate layer of a metal oxide and / or metal nitride and / or metal carbide and / or metal oxonitride and / or metal carbonitride and / or metal oxocarbonitride and the intermediate layer a in relation to the functional layer is very thin layer, wherein the intermediate layer interrupts the morphology of the functional layer.

PCT / EP03 / 10222 describes a method for the production of layers and layer systems as well as a coated substrate produced according to the method, wherein in the method at least one functional layer is applied, and this providing the substrate and the layer starting material in a vacuum system and the coating of the substrate with a functional layer by means of sputtering of the layer starting material and sputtering the layer source material for coating the substrate, and wherein the functional layer is interrupted at least once and an intermediate layer other than the functional layer is formed whose thickness is ≤ 210 nm and the sputtering of the layer source material is continued after the interruption.

PCT / EP03 / 10220 comprises a coated article having at least one functional layer, in which at least one intermediate layer is arranged in at least one functional layer, the intermediate layer has a layer thickness of d _z ≦ 10 nm and the intermediate layer interrupts the morphology of the functional layer.

The However, the interlayers described above are known in the art Layer systems introduced so that each one layer interrupt this layer system, this means between two at least be arranged from the material identical layers.

The DE 3 941 859 C1 teaches to adjust the refractive index of optical layers in an interference-optical layer system to use a mixture of SiO ₂ and TiO ₂ . Depending on the mixing ratio, refractive indices between that of TiO ₂ (about 2.5) and that of SiO ₂ (about 1.5) are possible:
Frequently, alternating optical layer systems with alternating high and low refractive index layers are used to produce coatings for cold light reflectors. These coating systems are partially applied by PICVD methods.

From none of the intermediate layers was an influence on the electrical conductivity of layer systems known. Furthermore, these layer systems were created by alternately an organic precursor and an inorganic precursor for coating has been used. The simultaneous use of an organic Precursors and an inorganic precursor has been in these Coatings, however, are strictly avoided to chemical reactions to avoid which partly to unwanted pollution lead from piping systems and reaction chambers.

In important applications of such layer systems can the electrical conductivity play an important role.

Reflectors for digital projection usually incorporate high intensity gas discharge lamps. These lamps are ignited with a voltage of several 1000 V. The power supply lines are partially guided through holes in the reflector and have, as far as these lines in the reflector, as usual not carried out in isolation, contact with the layer system, conductive layer systems then cause problems. The ignition voltage can be short-circuited by a conductive layer system, which prevents ignition of the lamp. The flange of several reflectors has built in th state contact with metal parts. The ignition voltage can be dissipated through these parts and damage other components or put housing parts under voltage.

Of the Invention is based on the object, a layer system with reduced electrical conductivity and a method for production of layer systems with reduced electrical conductivity provide.

Especially It would be advantageous if already existing layer systems essentially without changing the shift description can be maintained. These tasks come with a Method with the features of claim 1 and an article solved with the features of claim 13.

conventional Layer system have, for example, in interference-optical alternating-layer systems, Thicknesses of the applied layers of about 10 nm to 200 nm. Surprisingly the inventors have found that the introduction of thin intermediate layers in one or more of these interference optical Alternating layers a serious reduction in conductivity had this layer system result.

When thin intermediate layer was doing a layer with thicknesses from about 3 nm to 20 nm, preferably 3 nm to 10 nm, and especially preferably introduced from 4 nm to 6 nm.

Surprisingly the inventors have further found that these intermediate layers only then reduced the conductivity when an organic Precursor and an inorganic precursor simultaneously into the coating or reaction chamber was introduced and simultaneously to the reaction and / or deposition.

Further It was also surprising that these intermediate layers then greatly reduced the electrical conductivity, if these are between two layers of different material Composition were introduced.

Alternating shift systems with such intermediate layers have depending on manufacturing parameters a reduced to greatly reduced electrical conductivity. With 5000 V measurement voltage at inventive Layer systems electrical resistances in the high GΩ range or TΩ range measured. Whereas the same layer system without intermediate layers at a measuring voltage of 5000 V a lower one Resistance down to the kΩ range.

The Invention will be described below with reference to preferred embodiments and with reference to the accompanying figures in more detail described.

It demonstrate:

1 schematic representation of a layer system with mixed intermediate layers, which are incorporated in a conventional interference optical cold light mirror layer system,

2 Results of conductivity measurements, which reflect the influence of the mixed intermediate layers on the electrical resistance of oxide layer systems.

Detailed description more preferred embodiments

at the following described in more detail preferred embodiments were interference-optical alternating-layer systems on glass and glass ceramic reflectors applied, which had conventional layer designs, in which to reduce the conductivity intermediate layers were introduced.

These Intermediate layers are also referred to as mixed intermediate layers, as far as doing their production both organic and inorganic Precursors used at the same time or in particular as a mixture become.

The conventional layer system comprises multiple layers of SiO _x C _y and TiO _x Cl _y layers.

The layer systems consist of TiO _x Cl _y and SiO _x Cl _y layers of specific thickness and form an In interference layer system with defined spectrum.

The TiO _x Cl _y layers are made from a mixture of TiCl ₄ and O ₂ and usually contain chlorine radicals.

The SiO _x C _y layers are prepared from HMDSO-oxygen mixture ((CH ₃ ) ₃ -Si-O-Si (CH ₃ ) ₃ ) and contain carbon and hydrogen radicals.

The SiO _x C _y layers alone usually have almost no conductivity.

The TiO _x Cl _y layers have as a single layer only a low conductivity.

Only the combination of SiO _x C _y and TiO _x Cl _y layers in the layer system led to the observed high conductivity of the layer systems. The mechanism by which this conductivity is induced is currently unknown.

Surprisingly, the inventors have found that thin mixed layers interposed between the SiO _x C _y and TiO _x Cl _y layers can significantly reduce the conductivity of the alternating layer systems.

These are preferably prepared by simultaneously passing HMDSO, TiCl ₄ and O ₂ into the reactor.

The Coating time for these mixed intermediate layers is between one-tenth and several seconds, for example ten Seconds, preferably about one second.

The Conductivity reduction by this measure works both in glass reflectors and in glass-ceramic reflectors.

Mixed intermediate layers which are produced only from inorganic precursors, for example from SiCl ₄ and TiCl ₄ and O ₂ , show no reduction in conductivity.

Surprisingly performs the combination of an organic with an inorganic one Precursor but to a significant reduction in conductivity.

Mixed intermediate layers, which are interposed between the SiO _x C _y and TiO _x Cl _y layers of an oxide layer system, reduce the electrical conductivity of this layer system.

These intermediate layers are advantageously produced for example with a gas mixture of TiCl ₄ , HMDSO and O ₂ .

apparently it is necessary an organic with an inorganic precursor to mix to a conductivity-reducing effect to achieve.

Therefore, the conductivity reduction can not be done solely by forming a SiO ₂ -TiO ₂ mixed layer. There must be an interaction of further precursor constituents. In addition to silicon and oxygen, the HMDSO molecule also contains organic components, namely carbon and hydrogen, which appear to be essential for reducing the conductivity.

Embodiment 1: Effect the mixed layers on the laboratory.

One ellipsoidal glass-ceramic reflector with a height of approx. 5 cm and a maximum diameter of about 5 cm was for used the experiments shown below.

The coating of the test reflectors was done with a cold light mirror consisting of 15 layers TiO _x Cl _y and 16 layers SiO _x C _y . For the deposition of these layers, a plasma CVD method was used in which the plasma is generated by a pulsed microwave field (PICVD method). The pulse power for the SiO _x C _y layers was 3000 W and for the TiO _x Cl _y layers 2800 W.

A duty cycle of 0.02 was used for both layers, the duty cycle being the time Liche ratio between existing microwave radiation and switched off microwave irradiation describes.

Of the Pressure in the coating chamber was about 0.5 mbar.

Of the Influence of the coating gases and the exhaust of the exhaust gases took place continuously.

The SiO _x C _y layers were produced using a gas mixture of about 97% by volume O ₂ and 3% by volume hexamethylene disiloxane (HMDSO).

The TiO _x Cl _y layers were prepared with a mixture of about 0.5 vol.% And 2 vol.% TiCl ₄ in O ₂ , respectively.

The gas for the deposition of the mixed intermediate layers consisted of 3 vol.% HMDSO, 0.5 vol.% And 2 vol.% TiCl ₄ and 96.5 vol.% And 95 vol.% O, respectively ₂ .

Of the Pressure was 0.5 mbar, the pulse power 3000 W, the test ratio 0.02. In this example, the coating time for the mixed intermediate layers varies. First, some were Reflectors without mixed intermediate layers produced and measured.

These showed after annealing at 450 ° C for 20 min an increased conductivity (or low resistance).

The Resistance measurement took place at various points on the reflector surface with about 1000 V and an electrode spacing of the measuring electrodes of about 5 mm.

It Resistances could be down to single digits MΩ range can be measured.

With increasing coating time for the mixed intermediate layers the layer resistance increased. At one second coating time was after annealing at all measuring points on the reflector surface a resistance of> 2 GΩ, which is the final range of the used Meter corresponds.

Embodiment 2: Effect of the mixed layers in production

The Concept of mixed intermediate layers shown on a laboratory plant was transferred to a production plant and tested.

The test object was an ellipsoidal glass reflector with a height of approx. 6 cm and a maximum diameter of approx. 5.5 cm. The same layer system was applied to this reflector as in Example 1, but with different coating parameters: SiO _x C _y layers: Pulse power: 8000 W duty cycle: 0.028 HMDSO conc .: 2.7% by volume TiO _x I _y layers: Pulse power: 6000W duty cycle: 0.028 TiCl ₄ Conc. 1.1% by volume Mixed interlayers: Pulse power: 6000 or 8000 W duty cycle: 0.028 HMDSO conc .: 2.7% by volume TiCl ₄ : 1.1% by volume Coating time: 1 s

With These parcels were coated on the same system and made with mixed intermediate layers.

To the annealing of the samples was carried out measuring the electrical conductivity. For each reflector, the electrical resistance between different measure precisely defined points. The measuring voltage was 5000 V. The measuring range end value of the measuring instrument is 1 TΩ.

In 2 the results of the conductivity measurements on the layer systems described above are summarized.

These Results of conductivity measurements, respectively the influence of the mixed intermediate layers on the electrical Show resistance of oxide layer systems, respectively the same layering system, which in different places on the Surface was measured. The left higher Bars show the electrical resistance of a coating system without Intermediate layers and the right, bars essentially the same Layer system, however, without introduced intermediate layers.

you they that the electrical conductivity of the layer system significantly reduced by the intermediate layers at some measuring positions could be.

The Layer systems with mixed intermediate layers have many measuring positions one about 6 orders of magnitude higher electrical resistance.

This clearly shows that the inventive Conductivity reduction in industrial production plants is applicable.

The invention is also applied to those in the in PCT / EP03 / 10221 PCT / EP03 / 10219 PCT / EP03 / 10222 and PCT / EP03 / 10220 beschriebnenen method and the objects produced therein according to the method extended and it is the content of the PCT / EP03 / 10221 PCT / EP03 / 10219 PCT / EP03 / 10222 as well as the PCT / EP03 / 10220 by reference also to the subject matter of the present specification and the present application.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 03/10221 [0003, 0063, 0063]
• - EP 03/10222 [0004, 0063, 0063]
• - EP 03/10220 [0005, 0063, 0063]
• - DE 3941859 C1 [0007]
• - EP 03/10219 [0063, 0063]

Claims (16)

Process for the production of layer systems, in which on a subject a layer system with at least two layers is applied and at least one intermediate layer is introduced between the layers and in which to apply the intermediate layer is an organic precursor and an inorganic precursor Precursor at the same time and / or successively in the coating or reaction chamber is introduced and the organic precursor and inorganic precursors substantially simultaneously to the reaction and / or deposition is brought. Process for the preparation of layer systems according to Claim 1, wherein the organic precursor hexamethylene disiloxane (HMDSO) and / or tetramethyldisiloxane (TMDSO), tetraethylorthosilicate (TEOS), tetramethylcyclotetrasiloxane (TMCTSO). Process for the preparation of layer systems according to Claim 1 or 2, in which the inorganic precursor comprises TiCl ₄ and / or NbCl ₅ , TaCl ₃ , ZrCl 4. A method of making layer systems according to claim 1, 2 or 3, wherein the layers comprise at least one SiO _x C _y layer in which x is from 1.8 to 2.1 and y is <0.05, and at least one TiO _x Cl _y layer in which x is from 1.8 to 2.1 and y <0.02. Process for the production of layer systems according to one of the preceding claims, wherein for the composition of the intermediate layer a deposit comprising 0.5 to 10% by volume HMDSO, preferably 3% by volume HMDSO, 0.2 to 5% by volume TiCl ₄ , preferably 0.5 vol .-% to 2 vol .-% TiCl ₄ and 85 to 99.3 vol .-% O ₂ , preferably 96.5 vol .-% or 95 vol .-% O ₂ is used , Process for the production of layer systems according to one of the preceding claims, in which TiO ₂ layers and SiO ₂ layers are deposited alternately for the layer system and preferably the TiO ₂ layers of a mixture of TiCl ₄ and O ₂ and the SiO ₂ layers will be deposited from an HMDSO-oxygen mixture ((CH ₃ ) ₃ -Si-O-Si (CH ₃ ) ₃ ). Process for the preparation of layer systems according to one of the preceding claims, wherein the initiating and mixing the organic and inorganic precursors takes place in a feed in front of the coating chamber. Process for the preparation of layer systems according to one of the claims of 1 to 6, wherein the initiating of the organic and the inorganic precursor into the coating chamber takes place in two feeds and the mixing of the organic and the inorganic precursor in the coating chamber. Process for the preparation of layer systems according to one of the preceding claims, wherein the functional layer Part of an interference optical layer system is. Process for the preparation of layer systems according to one of the preceding claims, wherein a first of the at least two layers another material composition as a second of the at least two layers and the at least an intermediate layer is introduced between the first and second layers becomes. Process for the preparation of layer systems according to Claim 1, wherein the thickness of the intermediate layer of 3 nm to 10 nm is. Process for the preparation of layer systems according to Claim 1, wherein the coating process comprises CVD processes, in particular PECVD, PICVD. Object with a layer system with at least two layers and at least one intermediate layer between the Layers producible by a method according to claim 1 to 12. Object with a layer system with at least two layers and at least one intermediate layer between the Layers produced by a method according to claim 1 to 12. An article having the features of claim 13 or 14 comprising an interference-optical layer system. An article according to claim 15, comprising a glass or glass-ceramic reflector with an interference-optical dichroic mirror layer system.