JPS6154597B2 - - 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. (Tokuko Showa 53-40189)
issue). However, in this type, the installation location of the light emitters and receivers j and j is limited to immediately after each evaporation source c, so installation is relatively difficult, and the light emitting and receiving surfaces of the light emitters and receivers j and j are evaporated. This has the disadvantage that accurate measurements cannot be taken because it tends to fog up depending on the substance, and a large number of projectors j, j
This inevitably increases the cost of the equipment.

The purpose of the present invention is to eliminate these inconveniences by moving a workpiece over multiple evaporation sources in a vacuum processing chamber, forming a multilayer thin film thereon, and forming 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 by light between the light emitter and receiver to monitor the multilayer film thickness. In the type, the openings of the shielding plate were formed into a plurality of independent holes facing each evaporation source, and the openings were distributed on the sides in the direction of movement of the workpiece. It is characterized by

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 section in which the inside of the processing chamber 1 is unwound from one roll 3a and wound onto the other roll 3b. Polyester film and other workpieces that move as much as possible; 4 refers to the vacuum processing chamber 1;
A plurality of evaporation sources elongated in the width direction are shown in the lower part of the workpiece 2, facing the workpiece 2 and disposed in its movement direction, and the material evaporated from each evaporation source 4 moves above the workpiece 2. A multilayer thin film 5 is formed by being sequentially deposited on the surface. 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 thickness of the monitoring thin film 8 is monitored by a light emitter/receiver 9 consisting of a pair of light emitter 9a and light receiver 9b, and the amount of light transmitted or reflected from the thin film 8 from the light emitter 9a is amplified. 10. Measured with a light receiver 9b connected to the recording device 11,
When an abnormality in the thickness of the monitoring thin film 8 is measured, for example, the amount of evaporation from the evaporation source 4 is controlled to obtain a predetermined film thickness.

The above configuration is not particularly different from the conventional one, but in the present invention, the opening 6 of the shield plate 7 is formed into a plurality of independent holes facing each evaporation source 4, as shown in FIG. A part of the evaporated material from each evaporation source 4 is deposited as a monitoring thin film 8 on the monitoring zone 2a of the workpiece 2 above the hole 6a through the hole 6a, and The monitoring thin films 8 attached to the monitoring zone 2a through the openings 6 are arranged separately on the sides of the moving direction of the workpiece 2, and the monitoring thin films 8 are attached to the monitoring zone 2a for each evaporation source 4 as shown in FIG. It is now formed into a band-like shape divided into 2 sections. The thickness of each thin film 5, 8 is measured by measuring the amount of reflected light between multiple sets of light emitters and receivers 9 provided in front of the take-up roll 3b past each evaporation source 4. It may be provided behind the object 2 and the amount of transmitted light can be measured by applying a light beam as shown by the dotted line in FIG. Further, the light emitter 9a and the light receiver 9b constituting the light emitter/receiver 9 are arranged to face mirrors 12a, 12b which can freely travel along the workpiece 2 as shown in FIG.
When the workpiece 2b is run, the optical axis 13 is tilted and fixed in front of the workpiece 2.
4b and moves in the width direction of the workpiece 2, and the thickness of each of the thin films 5 and 8 can be measured by a pair of light emitter/receiver 9. The hole shapes 6a of each opening 6 can be arranged in a staggered manner as shown in FIG. 7, or triangular as shown in FIGS. 8 and 9.
The length of each opening 6 may be changed as shown in the figure. By arranging the openings 6 as shown in FIG. 8, thin films formed by odd-numbered evaporation sources and thin films formed by even-numbered evaporation sources can be formed separately on one side and the other side of the monitoring zone 2a. To explain its operation with reference to the embodiment shown in FIGS. 4 and 5, the roll 3
When a and 3b are rotated to move the workpiece 2 to the right in the drawing, evaporated substances such as ZnS and MgF ₂ from the lower evaporation sources 4 are deposited one after another, forming a multilayer on the lower surface of the workpiece 2. A thin film 5 is formed. At the same time, a single-layer belt-shaped monitoring thin film 8 for each evaporation source 4 is formed in the monitoring zone 2a through the hole-shaped opening 6, and the workpiece passes past each evaporation source 4 and is deposited on the roll 3b. The film thickness of each thin film 8 is measured by the light emitter/receiver 9 before the thin film 2 is wound up.

As described above, according to the present invention, independent hole-shaped openings are formed in the shielding plate facing each evaporation source,
Since the apertures are distributed laterally, a single layer of monitoring thin film can be formed for each evaporation source in the monitoring zone of the workpiece, and the thickness of these single layers can be compared using a light emitter and receiver. The monitoring accuracy is improved compared to conventional methods that measure the entire multi-layered thin film, and the measurement can be performed past each evaporation source, making it easy to install light emitters and receivers. This has the effect that the light emitting and receiving surfaces are less likely to become cloudy due to evaporated substances.

[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. FIG. 5 is a cross-sectional view taken along the - line, FIG. 6 is a diagram showing an example of the measuring state of the light emitter/receiver, and FIGS. 7 to 10 are diagrams showing modified examples of the aperture. 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, 6
a... Hole shape.

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,
A multilayer thin film characterized in that the openings of the shielding plate are configured in the form of a plurality of independent holes facing each evaporation source, and the openings are distributed on the sides in the moving direction of the workpiece. Film thickness monitoring device in forming equipment.