DE102006008975B4 - Method for coating a substrate in a vacuum coating chamber and vacuum coating system for carrying out the method - Google Patents

Abstract

Method for coating a substrate in a vacuum coating installation, wherein the substrate is placed on a substrate holder before or in a first chamber, the first chamber is subsequently closed against the atmosphere by means of a first vacuum valve and then evacuated, the substrate with the transport device being moved into a second chamber, which is carried out as a coating chamber and separated by a vacuum valve from the first chamber, transported after opening the second vacuum valve and is coated in this after closing the second vacuum valve and wherein the substrate is preheated prior to coating by means of a heater, wherein the preheating after closing of the first vacuum valve (4; 5) takes place in situ in the first chamber (1; 2), characterized in that, before the first vacuum valve (4; 5) is closed, the heating device (13; 14) is located outside the first chamber (1; 2), separated from this vacuum-tight, held and after closing the first vacuum valve (4; 5) at least during the preheating of the substrate (16;

Description

The invention relates to a method for coating a substrate in a vacuum coating system, wherein the substrate is placed on a substrate holder in front of or in a first chamber. The first chamber is then closed by means of a first vacuum valve against the atmosphere and then evacuated. The substrate is transported with the transport device into a second chamber, which is designed as a coating chamber and separated by a vacuum valve from the first chamber, after opening the second vacuum valve and coated therein after closing the second vacuum valve. The substrate is preheated before coating by means of a heating device.

Furthermore, the invention relates to a vacuum coating system for carrying out the method. This can be closed with a first vacuum valve against the atmosphere. It is a second vacuum chamber, which is connected to the first vacuum chamber and via a second vacuum valve is separable therefrom provided. Furthermore, the vacuum coating apparatus is provided with a substrate holder which is movable on a transport means through the first into the second vacuum chamber on a movement path, and provided with a heater.

There are vacuum coating systems of the type mentioned as a multi-chamber vacuum systems for vapor deposition of substrates with thermal protection layers known, which consist of several process chambers. According to the prior art, the substrates are usually attached to a substrate holder in the first chamber or before.

After an evacuation process step, a chamber valve is opened in this first chamber and the substrate holder with the substrates moved into a second heated chamber in which the substrates are heated. After the substrates have been heated, a further chamber valve is opened and the substrate holder with the substrates is guided into a further chamber, a vapor deposition chamber.

The US 3,586,632 describes a similar process. In this, a coating device is described, which consists of three vacuum chambers and are passed through the substrates to be coated. In this case, the first chamber is provided as a preheat chamber. From this, the substrate holder can be transferred into a coating chamber while opening a vacuum valve and be given by this after the coating in a cooling chamber.

If the substrate holder is designed as a sting with a transport device, the substrate holder with the substrates is moved back into the input chamber after vapor deposition, in which the substrates are cooled and removed therefrom.

In the case that the transport device is designed as a trolley, the substrate holder is cooled with the substrates and subsequently the substrates are removed from a removal chamber.

Plants in which the transport device is designed as a sting, are preferably designed so that a feed of the deposition chamber can be symmetrical.

It is a good utilization of the system made possible by the fact that each reciprocal Sting is moved from the right or from the left into the deposition chamber. Such systems usually consist of at least five chambers connected in series.

Since the sliding sting has approximately the length of a loading and heating chamber, results in a Doppelsting plant a total length of nine times the chamber length. This large chamber length is considerably disadvantageous. The successive chambers also bring the disadvantage that in a required maintenance or repair in one of the chambers, the associated chambers are also not ready.

The invention is based on the object, on the one hand to reduce the great length expansion of the system structure and on the other hand to improve execution of repairs of the system during the sputtering process.

The method-side solution according to the invention of the task is achieved in that the preheating takes place after closing the first vacuum valve in situ in the first chamber.

Since the evacuation of the first chamber takes place after closing the first vacuum valve, the heating of the substrate already takes place with extensive exclusion of atmospheric influences. Thus, for example, an oxidation of the heater or the substrate surface can be avoided. On the other hand, the first chamber is operated on the one hand as a vacuum lock and used as a preheating station, so that an additional preheating station is unnecessary, whereby the overall length is shortened.

In the embodiment of the method according to the invention it is provided that the heater before closing the first vacuum valve outside the first chamber of this vacuum-tight, held separately. After closing the first vacuum valve, the heater is introduced at least during the preheating of the substrate in the first chamber and spent at least again before a reopening of the first vacuum valve vacuum-tight separated from the first chamber.

To heat the substrate, the movable heating device is moved after an evacuation phase in the first chamber and led back to the starting point after the successful heating.

This makes it possible to keep the heater constantly at heating temperature, whereby temperature changes can be avoided. On the one hand, the heating device is thus immediately ready for operation at any time and the heating phase can be kept short. On the other hand, the vacuum-tight movement of the heater, while not required, allows the heater to remain in a vacuum, which in turn avoids atmospheric disturbances.

With this solution according to the invention, the number of chambers is reduced in the transport direction and there is a reduction z. B. the double-Stampf-evaporation system of about 9 chamber lengths to five chamber lengths.

Since the movable heater is separated from the first chamber during vapor deposition, unlike the prior art, a steaming of the heater, which consists mostly of graphite heaters, is prevented by scattering vapor during vapor deposition of the substrates.

When the third vacuum valve is closed, repairs can be made to the heater, even if a substrate is in the vapor deposition phase, for example, even if a sting is inserted in the vacuum coating system.

However, it is also possible to operate the vacuum coating system as a continuous system. It is thus achieved that the vapor deposition process in the vapor deposition chamber is established by continuous successive substrates experiencing a vaporization process step in the vapor deposition chamber, while the preceding and subsequent processing steps are carried out with the respective other substrates in upstream and downstream chambers.

In a favorable variant of the method according to the invention is also provided that the substrate is introduced by means of a Sting in the second chamber and discharged from this, wherein the heater after retraction of the Sting in the first chamber until retraction of the Sting in the second chamber in the first chamber is introduced.

Thus, it is achieved that the sputtering process in the vapor deposition chamber is established by successively subjecting substrates introduced into the vacuum deposition chamber from one side to a sputtering process step in the vapor deposition chamber, while removing other substrates from a sampling chamber.

The arrangement-side inventive solution of the problem is achieved in that a third chamber is provided, which is arranged next to the movement path and adjacent to the first chamber, that between the first and the third chamber, a third vacuum valve is arranged, and that the heating of the third in the first chamber and vice versa is designed to be movable.

The third chamber thus serves to store the heater during the time in which it is not needed to heat the substrate. After a retraction of the substrate in the first chamber, a vacuum is generated in this. Subsequently, the third vacuum valve can be opened. Since vacuum can be kept in the third vacuum chamber during the entire process, the vacuum in the first chamber is not or only marginally disturbed after an opening of the third vacuum valve. Now the heater can be moved into the first chamber and there heats the substrate. If the substrate is preheated, the function of the heater is fulfilled. This can now be moved back to the third chamber. Also, now the third vacuum valve can be closed.

Now the substrate is moved into the second chamber and coated there. For this purpose, the second vacuum valve is opened.

After coating, the substrate is cooled again. In a discontinuous vacuum coating system, ie one which does not realize a continuous operation, this cooling process will again take place in the first chamber. This is also possible, since the heater could already be extended out of the first chamber. In this case, the first chamber thus fulfills three functions: a lock function, the function of a preheat chamber and the function of a cooling chamber. The integration of these three functions in the first chamber in a discontinuous vacuum coating system shows particularly clearly what advantages with the Invention can be achieved because only a single chamber in the trajectory is required for the three functions, whereby the longitudinal extent of the system can be significantly reduced.

In one embodiment of the arrangement according to the invention it is provided that the third vacuum valve is designed as a flap valve. Thus, a relatively simple construction can be realized.

In a further embodiment, the transport device is designed as a sting. The use of a sting is a particularly simple realization of a transport device, through which a discontinuous operation is realized. As already shown above, the invention avoids significant disadvantages in the construction of discontinuously operating systems, so that in the embodiment with a sting, a low technical outlay can be achieved while reducing disadvantages.

For a better utilization of the second chamber is further provided that the mirror image of the second chamber, the first and third chamber is arranged a second time.

This configuration makes it possible to feed the second chamber from two sides in order to increase the utilization of the coating station.

The invention will be explained in more detail with reference to an embodiment. The accompanying drawing figure shows the schematic structure of a double-Sting-evaporation system.

Here are two first chambers 1 . 2 provided on both sides of a second chamber designed as evaporation chamber 3 are arranged. The first chambers 1 . 2 are opposite atmosphere with first vacuum valves 4 . 5 closable. Between the first chambers 1 . 2 and the second chamber 3 are second vacuum valves 6 . 7 arranged.

In the second chamber 3 becomes a cloud of steam 8th generated. At the first chambers 1 . 2 each are third chambers 9 . 10 arranged. The third chambers 9 . 10 can also with their first chambers 1 . 2 be integrated. The third chambers 9 . 10 are from their respective first chambers 1 . 2 via third vacuum valves 11 . 12 separated. The third vacuum valves 11 . 12 are designed as flap valves.

In the third chambers 9 . 10 are heating devices 13 . 14 arranged in the trajectory 15 the substrates 16 . 17 are movable.

For the introduction of a substrate 16 . 17 one and the other side will each have a sting 18 . 19 whose function is explained below on one page. At the introduction of the Sting 18 with the substrate attached thereto 16 in the first chamber 1 is a first vacuum valve 4 , open. The third vacuum valve 11 is closed.

With the positioning of the substrate 16 becomes the first vacuum valve 4 closed and the now closed first chamber 1 is evacuated.

After the evacuation of the first chamber 1 becomes the third vacuum valve 11 opened and the heater 13 in the first chamber 1 and around the substrate 16 positioned so that it is heated.

When the heating process is complete, the heater will turn on 13 back to her starting point in the third chamber 9 guided and the third vacuum valve 11 will be closed.

Now, the second vacuum valve 6 and thus the second chamber 3 and the substrate 16 moved to the designated place and the second chamber 3 closed, leaving in the cloud of steam 8th the evaporation of the substrate 16 can be done.

After completion of the sputtering process, the postprocessing process steps are processed, so that subsequently in the first chamber 1 again cooled substrate 16 is removed.

Then the same process is repeated on the other side. In the process, the substrate becomes 17 already in the first chamber 2 heated up while the substrate 16 in the second chamber 3 is coated so that the best possible utilization of the second chamber 3 can be achieved.

LIST OF REFERENCE NUMBERS

1

first chamber

2

first chamber

3

second chamber

4

first vacuum valve

5

first vacuum valve

6

second vacuum valve

7

second vacuum valve

8th

steam cloud

9

third chamber

10

third chamber

11

third vacuum valve

12

third vacuum valve

13

heater

14

heater

15

trajectory

16

substratum

17

substratum

18

Sting

19

Sting

Claims (6)

A method for coating a substrate in a vacuum coating system, wherein the substrate is placed on a substrate holder before or in a first chamber, the first chamber is then closed against atmosphere by means of a first vacuum valve and then evacuated, the substrate with the transport device into a second chamber, which is carried out as a coating chamber and separated by a vacuum valve from the first chamber, transported after opening the second vacuum valve and is coated in this after closing the second vacuum valve and wherein the substrate is preheated prior to coating by means of a heater, wherein the preheating after closing of the first vacuum valve ( 4 ; 5 ) in situ in the first chamber ( 1 ; 2 ), characterized in that the heating device ( 13 ; 14 ) before closing the first vacuum valve ( 4 ; 5 ) outside the first chamber ( 1 ; 2 ), held by this vacuum-tight, held and after closing the first vacuum valve ( 4 ; 5 ) at least during the preheating of the substrate ( 16 ; 17 ) into the first chamber ( 1 ; 2 ) and at the latest before a reopening of the first vacuum valve ( 4 ; 5 ) again vacuum-tight from the first chamber ( 1 ; 2 ) is spent separately. Method according to claim 1, characterized in that the substrate ( 16 ; 17 ) by means of a sting ( 18 ; 19 ) into the second chamber ( 3 ) is introduced and discharged from this, wherein the heating device ( 13 ; 14 ) after retracting the sting ( 18 ; 19 ) into the first chamber ( 1 ; 2 ) until the sting ( 18 ; 19 ) into the second chamber ( 3 ) into the first chamber ( 1 ; 2 ) is introduced. A vacuum coating apparatus for carrying out the method of claim 1, comprising a first vacuum chamber sealable with a first vacuum valve to atmosphere, a second vacuum chamber connected to the first vacuum chamber and separable therefrom by a second vacuum valve, a substrate holder mounted on a vacuum chamber Transport device is movable through the first in the second vacuum chamber on a movement path, and with a heating device, characterized in that a third chamber ( 9 ; 10 ) is provided next to the trajectory ( 15 ) and next to the first chamber ( 1 ; 2 ) is arranged that between the first ( 1 ; 2 ) and the third chamber ( 9 ; 10 ) a third vacuum valve ( 11 ; 12 ) and that the heating device ( 13 ; 14 ) of the third ( 9 ; 10 ) into the first chamber ( 1 ; 2 ) and vice versa is designed to be movable. Vacuum coating system according to claim 3, characterized in that the third vacuum valve ( 11 ; 12 ) is designed as a flap valve. Vacuum coating system according to claim 3 or 4, characterized in that the transport device as Sting ( 18 ; 19 ) is executed. Vacuum coating system according to claim 5, characterized in that a mirror image of the second chamber ( 3 ) the first ( 1 ; 2 ) and third chamber ( 9 ; 10 ) is arranged a second time.

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