JPS6154598B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a film thickness monitoring device in a multilayer thin film forming apparatus that forms a multilayer thin film of evaporated substances from a plurality of evaporation sources on a workpiece.

Conventionally, in this type of apparatus, a workpiece a is moved over a plurality of evaporation sources c in a vacuum processing chamber b as shown in FIGS. At the same time, a shielding plate f whose shielding width gradually decreases for each evaporation source interposed between the workpiece a and each evaporation source c is formed on a part e of the workpiece a. There is no known method in which a thin film h for monitoring is formed through an opening g, and the film thickness is monitored by measuring the newly exposed thin film h from each stage i using light emitters and receivers j, respectively. (Tokuko 1977-
No. 40189). Therefore, in this formula, the emitter and receiver j,
It is necessary to install a large number of evaporation sources j according to the number of thin film layers, and the installation location is limited to immediately after each evaporation source c, so there is a disadvantage that installation is relatively difficult.
Furthermore, as the number of layers of the thin film increases, the width of the monitoring thin film h that cannot be used as a product increases, resulting in increased losses and uneconomical disadvantages.

The purpose of the present invention is to solve these drawbacks.The present invention moves a workpiece over a plurality of evaporation sources in a vacuum processing chamber, forms a multilayer thin film thereon, and forms a thin film integrally with the workpiece. A monitoring thin film is formed through the opening of the shield plate interposed between this and each evaporation source, and the monitoring thin film is measured using light from a light emitter and receiver to monitor the film thickness of the multilayer thin film. In the case where the shielding plate has a plurality of openings arranged linearly along the moving direction of the workpiece and facing each evaporation source, each opening has a plurality of openings. It is characterized in that each part is provided with a shutter that opens and closes the shutter.

An example of the implementation of the apparatus of the present invention will be explained with reference to the attached drawings. In FIG. 4, 1 is a vacuum processing chamber, and 2 is a vacuum processing chamber in which one roll 3a is unwound and wound onto the other roll 3b. 4 indicates a plurality of evaporation sources elongated in the width direction, which are disposed in the lower part of the vacuum processing chamber 1 and facing the workpiece 2 in the moving direction thereof;
Substances evaporated from each evaporation source 4 are sequentially attached to the surface of the workpiece 2 moving above, forming a multilayer thin film 5.
is formed. Further, a shielding plate 7 having an opening 6 is interposed between the workpiece 2 and each evaporation source 4, and a monitoring zone prepared in advance on, for example, one side of the workpiece 2 is provided through the opening 6. A monitoring thin film 8 is formed on 2a. The monitoring thin film 8 includes a light projector 9a and a light receiver 9.
The thickness of the thin film 8 is monitored by a light projector/receiver 9 consisting of a pair of light projector 9a, and the amount of transmitted or reflected light from the light projector 9a is measured by an amplifier 10 and a recording device 1.
1, and if an abnormality in the film thickness of the monitoring thin film 8 is detected, the amount of evaporation from the evaporation source 4 is controlled to obtain the expected film thickness. be done.

The above configuration is not particularly different from the conventional one, but in the one of the present invention, the opening 6 of the shield plate 7 is arranged linearly along the moving direction of the workpiece 2, and each evaporation source 4 A part of the evaporated material from each evaporation source 4 passes through the opening 6 to the monitoring zone 2a of the workpiece 2 above the opening 6, and the monitoring zone 2a of the workpiece 2 is arranged in a straight line. Furthermore, each opening 6 is provided with a shutter 12 for opening and closing it, and by opening and closing each shutter 12 intermittently, a thin film of evaporated substances from each evaporation source 4 is deposited in the zone 2a. 8 are formed in separate linear arrays as shown in FIG.
In this case, if the shutter 12 can be opened and closed quickly, the thin film 8 is formed in a thick shape with an inclination 8a in the moving direction of the workpiece 2 as shown in FIG. When measuring the thickness, the output of the light emitter/receiver 9 is measured in front of the take-up roll 3b past each evaporation source 4 to the stationary portion 8b.

The opening 6 may be formed into a flat triangle or a flat pentagon as shown in FIGS.
As shown in FIGS. 0 and 11, each evaporation source 4 is placed in the part of the shielding plate 7 facing the zone 2b that becomes the product of the workpiece 2.
In the case of a device having two openings 13, a rectangular or triangular opening 6 having a shutter 12 may be formed continuously to the opening 13.

The operation will be explained with reference to the embodiment shown in FIGS. 4 and 5. When the workpiece 2 is moved to the right in the drawing by rotating the rolls 3a and 3b, ZnS and MgF are released from each evaporation source 4 below. Evaporated substances such as No. ₂ are deposited one after another, and a multilayer thin film 5 is formed on the lower surface of the workpiece 2. In this case, if the shutter 12a of the downstream opening 6a in the moving direction is opened for a certain period of time, and then the shutter 12b of the upstream opening 6b is opened for a certain period of time, the monitoring zone 2a of the workpiece 2 can be monitored as shown in FIG. A single-layer thin film 8 from each evaporation source 4 is formed linearly as shown in FIG.
This enables sequential measurement and monitoring. Therefore, when a thin film 8 that does not have the expected thickness appears, the evaporation source 4 that formed it can be determined by calculating backwards from the moving speed of the workpiece 2, for example, and the amount of evaporation is corrected to an appropriate amount. Although the shutters 12 have been described as being opened and closed in order from the downstream side, the present invention is not limited to this, and any arbitrary shutter may be opened and closed to form the single-layer thin film 8. Further, the workpiece 2 may be a lens or other single article that is attached to a long transport band and moved.

In this way, according to the present invention, a plurality of openings for forming the monitoring thin film are formed in a straight line and facing each evaporation source, and each opening is provided with a shutter, so that the monitoring thin film can be formed. can be formed intermittently and linearly, the number of light emitters and receivers installed to monitor the thin film can be reduced to one, and it can be manufactured at low cost, and the installation location can be separated from the evaporation source, making it easy to install. is less likely to be clouded by evaporated substances, and the monitoring band that forms the monitoring thin film can be relatively narrow, so there is less loss of workpieces. Since the multilayer thin film is monitored, monitoring accuracy is improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of a conventional example, FIG. 2 is a cross-sectional view taken along the line - FIG. 3 is an enlarged cross-sectional view of a multilayer thin film, and FIG. Figure 5 is a cross-sectional view taken along the line, Figure 6 is a bottom view of the workpiece, Figure 7 is a line diagram showing the formation state of the monitoring thin film, and Figures 8 to 11 are bottom views of modified examples of the opening. It is a diagram. 1... Vacuum processing chamber, 2... Workpiece, 4... Evaporation source, 5... Multilayer thin film, 6... Opening, 7...
Shielding plate, 8... Thin film for monitoring, 9... Light emitter/receiver, 1
2... Shyatsuta.

Claims (1)

[Claims] 1. A workpiece is moved over a plurality of evaporation sources in a vacuum processing chamber to form a multilayer thin film thereon, and an opening in a shield is interposed between the workpiece and each evaporation source. In a type in which a thin film for monitoring is formed through a part and the thin film for monitoring is measured by light between a light emitter and a receiver to monitor the film thickness of a multilayer thin film,
The openings of the shielding plate are configured into a plurality of openings arranged linearly along the moving direction of the workpiece and facing each evaporation source, and each opening is provided with a shutter for opening and closing the openings. A film thickness monitoring device in a multilayer thin film forming apparatus, characterized in that each device is provided with a multilayer thin film forming apparatus.