TW201350785A - Device for measuring film thickness and device for forming film - Google Patents

Abstract

Provided is a device for measuring film thickness capable of measuring optical film thickness with good precision. A device for measuring film thickness (6) comprising a projector (11) that projects light toward a monitor board (Sm) via a projector-side fiber (f1), an optical receiver (22) that receives, via a light receptor-side fiber (f2), light that is reflected by the monitor board (Sm) after being projected from the projector (11), and an optical sensing probe (13) formed by bundling a plurality of projector-side fibers (f1) and a plurality of light receptor-side fibers (f2), wherein a plurality of projector-side fiber (f1) end faces and a plurality of light receptor-side fiber (f2) end faces are disposed in the distal end face of the optical sensing probe (13) facing the monitor board (Sm). Each projector-side fiber (f1) end face is adjacent to a light receptor-side fiber (f2) end face and is arranged in an arcuate or annular shape, and each light receptor-side fiber (f2) end face is adjacent to a projector-side fiber (f1) end face and is arranged in an arcuate or annular shape.

Description

Film thickness measuring device and film forming device

The present invention relates to a film thickness measuring device and a film forming device equipped with the film thickness measuring device, and in particular, for measuring the optical film thickness formed on the substrate to be measured, the light is applied to the substrate to be measured through the optical fiber, and the light is passed through the optical fiber. A film thickness measuring device that receives reflected light reflected by a substrate to be measured, and a film forming device on which the film thickness measuring device is mounted.

In various fields in which optical films are utilized, it is desirable to form an optical film with good precision to achieve a specific film thickness. On the other hand, accurate film thickness measurement is indispensable for high-precision film thickness control of optical films. Here, the film thickness referred to herein is an optical film thickness which is determined by the physical film thickness and the refractive index of the film.

As a method for measuring the film thickness, a reflection type measuring method is known in which a phase difference is generated by a light reflected from a surface of an optical film and a path of light reflected at an interface between the substrate and the optical film. The film thickness was measured by the phenomenon of interference, and various apparatuses were proposed regarding the film thickness measuring apparatus using this measuring method.

An example of the film thickness measuring apparatus described in Patent Document 1 is a film thickness measuring device mounted in a film forming apparatus. In the device, light projected onto the optical film is transmitted from the light source through the optical fiber, and light reflected at the interface between the substrate and the optical film is transmitted through the optical fiber to the optical splitter.

Moreover, when the film thickness measuring device is mounted in a vacuum film forming apparatus, it is mounted. The substrate and the monitoring glass which finally become the multilayer film product are disposed together, and the film is formed by monitoring the glass under the same conditions as the substrate. Further, in the film forming step, the optical film thickness of the film formed on the side of the monitoring glass was measured, and the film formation condition was monitored. Thereby, the optical film thickness of each layer of the multilayer film formed on the substrate side can be measured. Further, in the prior vacuum film forming apparatus, in the film forming step, each time the layers of the multilayer film formed on the substrate are formed into a film, the glass is replaced with a new glass, that is, a film is formed. Pre-monitoring glass.

[Patent Document 1] Japanese Patent No. 3866693

However, in the measurement of the film thickness of the reflective type, when the light is incident at an angle with respect to the optical film of the substrate, the measured value of the film thickness is thinner than the film thickness of the light when the light is perpendicularly irradiated to the optical film, that is, originally The film thickness. Specifically, when the incident angle of the light with respect to the optical film of the substrate is θ, the refractive index of the optical film is n, and the original film thickness is d0, the measured value d of the film thickness is satisfied. The value of the formula (1).

d=(d0/n ² )×√{n ² -(sin θ) ² } (1)

Therefore, the larger the incident angle θ, the larger the measurement error Δd (=d0-d) of the film thickness, and the lower the measurement accuracy of the film thickness.

Further, as shown in FIG. 9, the incident angle θ corresponds to half the angle between the optical path of the light incident on the substrate and the optical path of the light reflected on the substrate side. Fig. 9 is an explanatory diagram regarding an incident angle.

In consideration of the relationship between the incident angle θ and the measurement error Δd of the film thickness, it is preferable that the area (effective emission range) of the portion of the actual irradiation light is as small as possible for the light projector that irradiates the optical film. The incident angle θ is decreased.

Further, in order to irradiate light with a high precision at a specific position of the optical film, a collecting lens may be provided between the light projector and the optical film, and the optical film may be irradiated with light through the collecting lens. Similarly, in order to reliably receive the reflected light reflected from the optical film, a light receiving lens may be disposed between the light receiver and the optical film, and the reflected light from the optical film may be received through the light receiving lens. In this case, the illuminance is attenuated corresponding to the amount of light passing through the lens, which has an effect on the measurement accuracy of the film thickness.

Further, if the monitoring glass is replaced every time the respective layers are formed on the substrate on which the multilayer film is formed, unevenness occurs between the monitoring glasses in terms of size, surface state, and processing accuracy, and the unevenness causes measurement accuracy of the film. The impact of the impact.

In addition, if the measurement of the optical film thickness cannot be accurately performed for the above reasons, the accuracy of the film thickness control performed by reflecting the measurement result is also lowered, and it is difficult to obtain a film having a desired film thickness.

Accordingly, an object of the present invention is to provide a film thickness measuring device capable of measuring an optical film thickness with good precision. Further, another object of the present invention is to provide a film forming apparatus which can control the film thickness of a film formed on a substrate with good precision based on an accurate measurement result of an optical film thickness.

According to the film thickness measuring apparatus of the present invention, the above problem can be solved by providing an irradiation apparatus which is formed of an optical fiber in order to measure the optical film thickness of the film formed on the substrate to be measured. The irradiation-side fiber is irradiated with light to the substrate to be measured, and the light-receiving device receives the light-receiving fiber made of an optical fiber and is reflected by the substrate for measurement after being irradiated from the irradiation device. And a probe which is formed by binding a plurality of the above-mentioned irradiation side fibers and a plurality of the above-mentioned light-receiving side fibers; An end surface of the plurality of the irradiation-side fibers and an end surface of the light-receiving side fiber are disposed on the opposite surface of the opposite side of the substrate to be measured, and the plurality of the opposite surfaces are disposed on the opposite surface. Each of the end faces of the irradiation-side fibers is arranged in an arc shape or an annular shape in a state of being adjacent to an end surface of at least one of the light-receiving-side fibers, and each of the end faces of the light-receiving side fibers disposed in a plurality of positions Each of them is arranged in an arc shape or an annular shape in a state adjacent to each of the end faces of at least one of the irradiation-side fibers.

In the above-mentioned film measuring apparatus, the opposite surface of the probe which is provided on the side opposite to the substrate to be measured is the self-irradiating device when the end faces of the irradiation-side fibers and the end faces of the light-receiving fibers are adjacent to each other. The angle of incidence of the light that illuminates the film is further reduced.

Specifically, when the end faces of the irradiation-side fibers and the end faces of the light-receiving fibers are adjacent to each other, the light irradiated from the end faces of the irradiation-side fibers is transferred to the film as compared with the case where the end faces of the two fibers are not adjacent to each other. The angle of the light path and the optical path when the light is reflected by the substrate for measurement and goes to the end surface of the light-receiving side fiber is further reduced. On the other hand, since the incident angle is 1/2 of the angle formed by the two optical paths, the incident angle is further reduced when the end faces of the irradiation-side fibers and the end faces of the light-receiving fibers are adjacent to each other. As described above, when the incident angle is decreased, the measurement error Δd is reduced in accordance with the relationship between the incident angle and the measurement error Δd of the film thickness (specifically, the above formula (1)).

Further, when the end faces of the irradiation side fibers and the end faces of the light receiving side fibers are adjacent to each other, the reflected light can be efficiently received by the light receiving side fibers.

Further, the higher the filling rate of the optical fiber of the end face of the probe, the higher the accuracy of the film thickness measurement. Therefore, the end face of the optical fiber is usually arranged in a dense state in the end face of the probe. On the other hand, the denser the end faces of the optical fibers, the end faces of the fibers on the irradiation side and the end faces of the fibers on the light receiving side are more distant from each other. Easy to intensive. On the other hand, when the end faces of the probes are arranged such that the end faces of the irradiation-side fibers and the end faces of the light-receiving fibers are arranged in an arc shape or an annular shape, the fibers on the irradiation side can be efficiently realized. The fibers on the light-receiving side are disposed adjacent to each other.

As described above, the film thickness measuring device described in claim 1 can measure the optical film thickness with higher accuracy than the prior art device.

Further, in the film thickness measuring device, it is preferable that the probe is in a state in which the optical component is not provided between the opposite surface and the substrate to be measured, and the opposite surface and the measurement target are used. The non-film formation faces on the opposite side of the substrate on the side where the film is formed are opposed to each other.

In the above configuration, since the collecting lens or the light receiving lens is not used, light loss can be suppressed, and when the reflected light is received by the light receiving side fiber, the reflected light can be received with a relatively large illuminance. Further, in accordance with the extent to which the amount of light received by the light-receiving side fibers is increased, the S/N ratio at the time of spectroscopic analysis of the light is increased in order to calculate the film thickness. Therefore, according to the configuration described in the claim 2, the optical film thickness can be measured with higher precision.

Further, in the film measuring device, it is preferable that the plurality of the irradiation side fibers and the plurality of light receiving side fibers constituting the probe are formed as bundle fibers having end faces aligned on the opposite faces, and the opposite direction The distance between the surface and the film formation surface is twice or more the diameter of the bundled optical fiber.

In the above configuration, the incident angle of light to the film, in other words, the angle of reflection of the light reflected by the film, is equal to or less than the numerical aperture NA of the light-receiving fiber. In this case, the light-receiving efficiency when light is received by the light-receiving side fiber is further improved. Therefore, according to the configuration described in the claim 3, the optical film thickness can be measured with better accuracy.

Further, in the film measuring device, the substrate to be measured may be a disk Shaped or annular substrate. In other words, in the configuration described in the claim 4, the optical film thickness of the film formed on the disk-shaped or annular substrate to be measured can be measured with good precision. Further, in the film thickness measuring device capable of performing multi-point monitoring of the film thickness, when a disk-shaped or annular substrate is used, the number of monitoring points can be further increased as compared with, for example, a rectangular substrate.

Further, the film measuring device may further include: the irradiation device; a DC stabilized power supply that supplies a direct current to a light source provided in the irradiation device; and the probe; the spectroscope includes the light receiving device, and outputs The light receiving device receives an analog signal corresponding to the received light intensity when the light reflected by the substrate to be measured is received; the amplifier: amplifies the analog signal outputted from the optical splitter; and the A/D converter: which is to be used by the amplifier Converting the above analog signal into a digital signal; an electronic computer: calculating the optical film thickness based on the digital signal; and a signal processing circuit: between the A/D converter and the electronic computer, the electronic The computer calculates the optical film thickness to perform specific signal processing on the digital signal. In other words, the configuration described in the claim 5 includes the same equipment as that of the conventional thin film measuring device, and the optical film thickness of the film can be measured with good precision.

Further, as long as it is the film forming apparatus of the present invention, the above problem can be solved by a film forming apparatus for forming a film on the substrate by vapor-depositing a vapor deposition material on the surface of the substrate in a vacuum vessel. And an evaporation mechanism for evaporating the vapor deposition material, and an opening and closing member for opening and closing the route for blocking the vapor deposition material evaporated by the evaporation mechanism to the surface of the substrate; and a control mechanism: The opening and closing of the opening and closing member; and the film thickness measuring device according to any one of claims 1 to 5; wherein the evaporation is performed in a state in which both the substrate and the substrate to be measured are housed in the vacuum container The mechanism makes the above vapor deposition material Evaporating to deposit the vapor deposition material on the surfaces of the both, wherein the film thickness measuring device measures the optical film thickness of the film formed on the substrate to be measured, and the control means is obtained by the film thickness measuring device. The opening and closing of the opening and closing member is controlled as a result of measurement of the optical film thickness.

Since the film forming apparatus configured as described above includes the film thickness measuring device that exhibits the above-described effects, the film thickness can be measured with good precision, and the film thickness can be controlled based on the measurement result. Therefore, in the film forming apparatus described in the claim 6, the film thickness of the film formed on the substrate can be controlled with good precision based on the accurate measurement result of the optical film thickness.

Further, in the film forming apparatus, it is preferable that the same substrate to be measured is disposed in the vacuum container while the multilayer film is formed on the substrate, and the multilayer film is formed on the substrate to be measured. The film thickness measuring device measures the optical film thickness of each of the multilayer films formed on the substrate to be measured.

According to the above configuration, when the multilayer film is formed on the substrate, the substrate for measurement is not replaced, and the optical film thickness of the film of each layer is measured each time the respective layers of the multilayer film are formed on the substrate to be measured. It is suppressed that the influence of the substrate to be measured changes when the film thickness of each layer is measured each time. Therefore, in the film forming apparatus described in the claim 7, the film thickness of each layer of the multilayer film formed on the substrate can be measured with good precision, and the film thickness control can be performed with better precision based on the measurement result. .

The film thickness measuring device described in claim 1 can measure the optical film thickness with higher precision than the prior art device.

The film thickness measuring device described in claim 2 can measure the optical film thickness with better accuracy in accordance with the degree of improvement in the S/N ratio of the spectroscopic analysis.

In the film thickness measuring device described in claim 3, the reflection angle of the light reflected by the film is affected by Since the optical side fiber has a numerical aperture NA or less, the optical film thickness can be measured with better precision.

The film thickness measuring device described in the claim 4 can measure the optical film thickness of the film formed on the disk-shaped or annular substrate to be measured with good precision. Further, in the film thickness measuring device capable of performing multi-point monitoring of the film thickness, when a disk-shaped or annular substrate is used, the number of monitoring points can be further increased as compared with the rectangular substrate.

The film thickness measuring device described in claim 5 has the same equipment as that of the conventional film measuring device, and the optical film thickness of the film can be measured with good precision.

The film forming apparatus described in claim 6 can measure the film thickness with good precision, and based on the measurement result, the film thickness control can be performed with good precision.

In the film forming apparatus of the seventh aspect, when the optical film thickness of each layer of the multilayer film formed on the substrate is measured, it is possible to suppress the influence of each substrate on the substrate to be measured, and accordingly, it is possible to obtain a favorable effect. The film thickness of each layer of the multilayer film formed on the substrate is measured with accuracy, and film thickness control can be performed with better precision based on the measurement result.

1‧‧‧vacuum container

2‧‧‧Substrate holder

2a‧‧‧ openings

3‧‧‧Evaporation mechanism

4‧‧‧ blocking

5‧‧‧Block control unit

6‧‧‧ Film thickness measuring device

11‧‧‧Light projector

12‧‧‧DC stabilized power supply

13‧‧‧Probes for optical sensors

14‧‧‧ Spectroscope

15‧‧‧Amplifier

16‧‧‧A/D converter

17‧‧‧Signal Processing Circuit

21‧‧‧Light source

22‧‧‧Light receiving device

23‧‧‧Hose

24A‧‧‧ joint connector

24B‧‧‧ joint connector

24C‧‧‧Intermediate connector

25‧‧‧protection cylinder

25a‧‧‧The Great Trails Department

25b‧‧‧Little Trails Department

100‧‧‧Vacuum evaporation device

F1‧‧‧illuminated side fiber

F2‧‧‧light-receiving fiber

PC1‧‧‧1st computer

PC2‧‧‧2nd computer

PLC‧‧‧programmable logic controller

S‧‧‧ actual substrate

Sm‧‧‧ monitoring substrate

Θ‧‧‧incidence angle

Fig. 1 is a view showing a schematic configuration of a film forming apparatus of the embodiment.

Fig. 2 is a schematic side view of the probe of the embodiment.

3(A) and 3(B) are views showing the arrangement positions of the optical fibers in the first example.

Fig. 4 is a view showing the arrangement position of the optical fibers in the comparative example.

5(A) and 5(B) are views showing the arrangement positions of the optical fibers in the second example.

Fig. 6 is an explanatory diagram showing the effectiveness of the arrangement position of the optical fibers in the present embodiment.

7(A) and (B) are diagrams showing other changes in the second example.

8(A) and 8(B) are views showing the arrangement positions of the optical fibers in the third example.

Fig. 9 is an explanatory diagram regarding an incident angle.

Hereinafter, an embodiment (hereinafter referred to as the present embodiment) of the present invention will be described with reference to the drawings.

First, a schematic configuration of a film formation structure of the present embodiment will be described with reference to Fig. 1 . Fig. 1 is a view showing a schematic configuration of a film forming apparatus of the embodiment.

The film forming apparatus of the present embodiment is a device for forming a multilayer film on a substrate by vapor-depositing a vapor deposition material on a surface of a substrate in a vacuum container, in particular, a vacuum vapor deposition device for forming a film by a vacuum evaporation method. 100. In the vacuum vapor deposition apparatus 100 of the present embodiment, a substrate (hereinafter referred to as an actual substrate S) and a monitoring substrate Sm for measuring a film thickness are provided in the vacuum chamber 1, and the film formed on the side of the monitoring substrate Sm can be measured. The film thickness of the film formed on the actual substrate S side is controlled based on the measurement result based on the optical film thickness.

Here, the actual substrate S refers to a substrate that is actually mounted on a film utilization device, and is made of, for example, glass. On the other hand, the monitoring substrate Sm corresponds to the substrate to be measured, and is used only for the film thickness monitor, and is made of the same material as the actual substrate S, for example, glass. In particular, the monitoring substrate Sm of the present embodiment has an annular substrate in a plan view, and preferably has a thickness of 1.0 to 2.0 mm.

Further, in the present embodiment, the multilayer substrate is formed under the same conditions as the actual substrate S on the substrate Sm. In other words, in the present embodiment, the optical film thickness of the film formed on the actual substrate S side and the optical film thickness of the film formed on the side of the monitoring substrate Sm are observed together, and the optical film thickness of the film on the side of the monitoring substrate Sm is observed. Monitoring, and managing the light of the film on the side of the actual substrate S Learn to thicken the film.

When the configuration of the vacuum vapor deposition apparatus 100 is described, as shown in FIG. 1, the vacuum container 1, the substrate holder 2, the evaporation mechanism 3, the shutter 4, the shutter control unit 5, and the film thickness measuring device 6 are provided.

A dome-shaped substrate holder 2 is housed in a space above the inner space of the vacuum container 1, and a plurality of actual substrates S are mounted on the inner surface of the substrate holder 2. Further, an opening 2a is formed at a center position of the inner surface of the substrate holder 2, and one monitoring substrate Sm is disposed at a position directly below the opening 2a. The monitoring substrate Sm disposed at this position is in a state in which a part thereof is exposed to the outside of the dome through the opening 2a.

Further, for the purpose of uniformizing the amount of film formation between the actual substrates S, the substrate holder 2 is rotated about the rotation axis in the vertical direction during the film formation period. In the meantime, the monitoring substrate Sm is relatively rotated with respect to the substrate holder 2. That is, in the present embodiment, the monitoring substrate Sm is held by a monitoring substrate holder (not shown) which is formed separately from the substrate holder 2, and the substrate holder 2 and the monitoring substrate holder are rotatable independently of each other.

On the other hand, an evaporation mechanism 3 is provided in a space below the space inside the vacuum vessel 1. The evaporation mechanism 3 is for evaporating a vapor deposition material which is vapor-deposited on the actual substrate S or the monitoring substrate Sm in order to form a thin film. Specifically, the evaporation mechanism 3 of the present embodiment is of the same type as the evaporation mechanism normally provided in the vacuum vapor deposition apparatus, and for example, a vapor deposition material held by a crucible (not shown) by an electron beam is used. An electron beam device or the like that is heated to evaporate.

A shutter 4 is provided between the substrate holder 2 and the evaporation mechanism 3. The shutter 4 is an example of an opening and closing member, and the vapor deposition material evaporated by the evaporation mechanism 3 is blocked to the actual substrate S. Alternatively, the route when the surface of the substrate Sm is monitored is opened and closed by a drive mechanism (not shown). Specifically, when the shutter 4 is in the open position (the position of the shutter 4 indicated by the solid line in FIG. 1), the evaporation material evaporated by the evaporation mechanism 3 is scattered and can be supplied to the actual substrate S or monitored. Substrate Sm. On the other hand, when the shutter 4 is in the closed position (the position of the shutter 4 indicated by a broken line in FIG. 1), the evaporation of the vapor deposition material is prevented by the shutter 4, and as a result, the actual substrate S or the monitoring substrate Sm cannot be supplied. Evaporation material.

The shutter control unit 5 corresponds to a control unit that controls opening and closing of the shutter 4, and is configured by the second computer PC2 described below in the present embodiment. Specifically, the second computer PC2 is connected to the shutter 4 via a interface (not shown), and the control program attached to the second computer PC2 is executed to output a control signal to the shutter 4. Further, when the shutter 4 receives the control signal from the second computer PC2, the opening and closing operation is performed in accordance with the control signal.

The film thickness measuring device 6 is a device for measuring the optical film thickness of the film formed on the monitoring substrate Sm. In particular, in the present embodiment, the film thickness is measured by a reflection method. In the film thickness measuring device 6 of the present embodiment, the light incident on the monitoring substrate Sm receives the light reflected by the monitoring substrate Sm, and then splits the reflected light to detect the light intensity at each wavelength (spectrum ). Then, based on the detected light intensity, the optical film thickness of the film formed on the monitoring substrate Sm is calculated.

Further, the film thickness measuring device 6 of the present embodiment measures the optical film thickness of each film formed in the multilayer film of the monitoring substrate Sm. More specifically, as described above, the monitoring substrate Sm is rotated independently of the substrate holder 2, and a monitoring substrate mask (not shown) is disposed directly under the monitoring substrate Sm. The monitoring substrate mask is a disk-shaped member, and an opening is formed in a central portion thereof. Monitoring a portion of the substrate Sm through the opening to the evaporator Structure 3 is exposed.

On the other hand, in a state in which both the actual substrate S and the monitoring substrate Sm are accommodated in the vacuum chamber 1, the evaporation mechanism 3 evaporates the vapor deposition material to vapor-deposit the vapor deposition material on both surfaces. Thereby, a film is formed on substantially the same condition on the film formation surface of each of the actual substrate S and the monitor substrate Sm. At this time, the region where the thin film is formed in the film formation surface of the monitoring substrate Sm is only the region exposed by the opening formed in the monitor substrate mask.

Further, as described above, in the present embodiment, the multilayer film is formed on the actual substrate S, and each time a thin film of each layer is formed, the vapor deposition material and the film formation conditions are replaced with materials and conditions for forming the film of the next layer. On the other hand, the multilayer film is formed on the monitoring substrate Sm under substantially the same conditions as the substrate. In the present embodiment, the monitoring of the substrate Sm with respect to the stationary state is monitored at the time when the vapor deposition material and the film forming conditions are replaced by the completion of one film. The substrate is masked and the relative rotation is only performed at a specific rotation angle. In this manner, since the monitoring substrate Sm is relatively rotated with respect to the monitoring substrate mask, the area exposed by the opening formed in the monitoring substrate mask in the monitoring substrate Sm is only shifted by the above-described rotation angle, and as a result, formed The area of the film is only offset by the above-described rotational angle.

Then, in the film forming process thereafter, the region exposed before the rotation in the monitoring substrate Sm (hereinafter referred to as the exposed region before the rotation) and the region exposed after the rotation (hereinafter referred to as the exposure after the rotation) The repeating range of the area) forms a film of the new layer. On the other hand, in the exposed area before the rotation, the film does not form a new layer without overlapping the exposed area after the rotation. Therefore, the film thickness of the film formed by each film formation process is not exposed to the region after the rotation of the substrate Sm immediately before the film formation process is performed, and after the rotation operation. The optical film thickness of the film formed between the regions was determined and compared.

Next, the film thickness measuring device of the present embodiment is faced with reference to FIGS. 1 and 2 The configuration of the sixth is explained. Fig. 2 is a schematic side view of the probe of the embodiment.

As shown in FIG. 1, the film thickness measuring device 6 includes a light projector 11, a DC stabilized power supply 12, an optical sensor probe 13, a beam splitter 14, an amplifier 15, an A/D converter 16, and a signal processing circuit 17, Two computers PC1 and PC2 are main components.

The light projector 11 is an example of an irradiation device. In order to measure the optical film thickness of the film formed on the monitoring substrate Sm, the irradiation substrate fiber f1 composed of an optical fiber is irradiated with light to the monitoring substrate Sm. Specifically, the light projector 11 has a light source 21 composed of a halogen lamp or the like, and the white light emitted from the light source 21 is irradiated from the front end surface of the probe 13 for the optical sensor in which the end surface of the irradiation side fiber f1 is disposed. Here, the light projector 11 is synchronized with the spectroscope 14, and the light source 21 is turned off and on in synchronization with the output period of the incident light intensity in the spectroscope 14. Further, a direct current is supplied from the DC stabilized power source 12 to the light source 21 included in the light projector 11.

The spectroscope 14 includes a light receiving device 22, and outputs an analog signal corresponding to the received light intensity when the light receiving device 22 receives the light reflected by the monitoring substrate Sm. More specifically, the light-receiving device 22 included in the spectroscope 14 is configured by, for example, a CCD (Charge Coupled Device), and the light-receiving side fiber f2 composed of an optical fiber is measured for measuring the optical film thickness. The light reflected by the monitoring substrate Sm after being irradiated from the light projector 11 is received. The spectroscope 14 splits the light received by the light receiving device 22, detects the light intensity (spectrum) at each wavelength, and outputs an electrical signal corresponding to the detection result. Here, the electrical signal output from the optical splitter 14 corresponds to an analog signal corresponding to the received light intensity when the light receiving device 22 receives the reflected light.

Further, the spectroscope 14 splits the light irradiated from the light projector 11 and outputs an electric signal indicating the intensity of light at each wavelength of the incident light, that is, the intensity of the incident light. As described above, the spectroscope 14 outputs an electrical signal indicating the intensity of the incident light and an electrical signal indicating the intensity of the reflected light. from The above two types of electrical signals output by the beam splitter 14 are amplified by the amplifier 15, respectively, and then converted into digital signals by the A/D converter 16. Thereafter, the digital signal is input to the second computer 19.

An example of the probe 13-series probe for an optical sensor is formed by bundling a plurality of irradiation-side fibers f1 and a plurality of light-receiving fibers f2. Specifically, as shown in FIG. 2, the plurality of irradiation-side fibers f1 connected to the light projector 11 and the plurality of light-receiving side fibers f2 connected to the light-receiving device 22 respectively form bundles and are housed in the hose 23 Inside.

Further, each of the irradiation-side fiber f1 and the light-receiving-side fiber f2 has a core and a cover core. In the present embodiment, the core diameter is about 200 μm, and the coated fiber diameter is about 235 μm.

Further, in the bundle formed by the irradiation side fiber f1, the joint connector 24A is attached to the end connected to the side of the light projector 11. Similarly, in the bundle formed by the light-receiving side fiber f2, the joint connector 24B is attached to the end connected to the side of the light-receiving device 22.

Then, the bundled irradiation-side fiber f1 and the light-receiving-side fiber f2 are combined at the free end side to form a probe 13 for an optical sensor. In other words, the plurality of irradiation side fibers f1 and the plurality of light receiving side fibers f2 constituting the optical sensor probe 13 are formed into bundle optical fibers whose end faces are aligned on the free end side of the optical sensor probe 13.

More specifically, as shown in FIG. 2, the bundles of the optical fibers f1 and f2 are joined to the intermediate connector 24C to be combined and bundled, and housed in the same hose 23. Further, in the irradiation-side fiber f1 and the light-receiving-side fiber f2 which are in a state of being combined, a cylindrical protective cylinder 25 is attached to the end portion on the side which is the free end, and the protective cylinder 25 is housed therein. The optical fibers f1 and f2 are disposed in the vacuum container 1.

The protective cylinder 25 is composed of a large diameter portion 25a and a small diameter portion 25b having different diameters, and the small diameter portion 25b is formed as a front end portion of the optical sensor probe 13. Moreover, optical sensor The probe 13 is provided such that one end surface of the small diameter portion 25b as the front end surface faces the monitoring substrate Sm at a position directly above the monitoring substrate Sm. In other words, one end surface of the small diameter portion 25b on the front end surface of the probe 13 for forming the optical sensor corresponds to the opposite surface provided on the side opposite to the optical probe 13 and the monitoring substrate Sm.

In the small-diameter portion 25b, the end faces are aligned so that the irradiation-side fiber f1 and the light-receiving-side fiber f2 are flush with each other. Therefore, the end faces of the plurality of irradiation side fibers f1 and the end faces of the light receiving side fibers f2 are disposed on one end surface of the small diameter portion 25b. In the present embodiment, the end surface of the irradiation-side fiber f1 and the end surface of the light-receiving side fiber f2 are regularly arranged on one end surface of the small-diameter portion 25b. Hereinafter, the arrangement positions of the optical fibers f1 and f2 on one end surface of the small diameter portion 25b will be described in detail.

As described above, the probe 13 for an optical sensor of the present embodiment is configured by combining bundles of the plurality of irradiation-side fibers f1 and the light-receiving-side fibers f2 into a bundle of optical fibers. In the present embodiment, the number of each of the irradiation-side fiber f1 and the light-receiving-side fiber f2 constituting the optical sensor probe 13 is 20 or more. Thereby, the film thickness measuring device 6 of the present embodiment can perform multi-point monitoring of the film thickness.

The two computers PC1 and PC2 can communicate with each other via Ethernet (registered trademark), and the first computer PC1 as one computer controls the light projector 11. In the present embodiment, the first computer PC1 controls the light irradiation operation of the light projector 11 via a programmable logic controller PLC (Programmable Logic Controller) in order to perform communication protocol conversion. As an example of the second computer PC2 electronic computer of another computer, the digital signal generated by converting the electric signal output from the optical splitter 14 by the A/D converter 16 is used to calculate the film formed on the monitoring substrate Sm. Optical film thickness.

Further, a signal processing circuit 17 is interposed between the A/D converter 16 and the second computer PC2. The signal processing circuit 17 performs a specific signal processing on the digital signal when the second computer PC2 calculates the optical film thickness. Here, the specific signal processing refers to a process of converting the above-mentioned digital signal into a signal of a better form for the optical film thickness calculation by the second computer PC2, for example, removing a wavelet of a component other than the interference signal. (wavelet) processing or frequency analysis processing.

Further, the second computer PC2 corresponds to a control unit that controls opening and closing of the shutter 4 as described above, and controls opening and closing of the shutter 4 based on the calculated value of the optical film thickness. Here, the calculated value of the optical film thickness calculated by the second computer PC2 is the measurement result of the optical film thickness obtained by the film thickness measuring device 6.

The configuration of the film thickness measuring device 6 of the present embodiment described above is common to the configuration of the conventional reflective film thickness measuring device, but is different from the prior devices in the four aspects described below.

The first difference is that an optical component such as a collecting lens or a light receiving lens is not provided between the end surface of the optical sensor probe 13 and the monitoring substrate Sm. In the present embodiment, the optical sensor probe 13 is in a state where no optical component is provided between one end surface of the small-diameter portion 25b formed as the distal end surface and the monitoring substrate Sm, as shown in FIG. One end surface of the small diameter portion 25b faces the non-film formation surface of the monitoring substrate Sm. Here, the non-film formation surface refers to a surface of the substrate Sm on the side opposite to the side on which the film is formed.

As described above, by providing no optical component between the end surface of the optical sensor probe 13 and the monitoring substrate Sm, in the present embodiment, light loss due to the optical component can be suppressed. As a result, the light-receiving side fiber f2 can receive the reflected light with a relatively large illuminance. and, Corresponding to the extent to which the amount of light received by the light-receiving side fiber f2 is increased, the S/N ratio at the time of spectroscopic analysis of the light is increased in order to calculate the film thickness. Therefore, the film thickness measuring device 6 of the present embodiment can measure the optical film thickness with good precision.

In the case where the optical component is not provided between the end surface of the optical sensor probe 13 and the monitoring substrate Sm, the diameter of the effective light-emitting point can be regarded as equivalent to the irradiation-side fiber f1 and the light-receiving side fiber f2. The diameter of the bundled fiber formed, that is, the diameter of the bundled fiber. Here, the bundle fiber diameter refers to the two end faces which are the farthest apart from the end faces of the plurality of irradiation side fibers f1 disposed on the end surface of the optical sensor probe 13 and the end faces of the plurality of light receiving side fibers f2. The predetermined length is about 1.8 mm in this embodiment.

The second difference is that the distance between the front end surface of the optical sensor probe 13 and the film formation surface of the monitoring substrate Sm is twice or more the diameter of the bundle fiber. With such a configuration, the angle of incidence of the light with respect to the film, in other words, the angle of reflection of the light reflected by the film, becomes equal to or less than the numerical aperture NA of the light-receiving side fiber f2. In the present embodiment, the distance between the front end surface of the optical sensor probe 13 and the film formation surface of the monitor substrate Sm is ensured to be twice or more the diameter of the bundle fiber by the above properties. As a result, the light receiving efficiency when light is received by the light-receiving side fiber f2 is further improved, and the optical film thickness can be further measured with good precision.

Further, when the distance between the front end surface of the probe 13 for the optical sensor and the film formation surface of the monitor substrate Sm is excessively shortened, the incident angle of the light with respect to the film and the reflection angle of the light reflected by the film become large. The light receiving efficiency of the probe 13 for the optical sensor (the ratio of the amount of light received by the optical sensor probe 13 to the amount of reflected light) is lowered, so that the measurement accuracy is lowered. On the other hand, if the distance between the front end surface of the probe 13 for the optical sensor and the film formation surface of the monitor substrate Sm is excessively long, the self-light is reflected from the film to the probe 13 by the optical sensor. The degree of attenuation in the period until acceptance is increased, so the measurement accuracy is lowered. On the other hand, if the distance between the front end surface of the probe 13 for the optical sensor and the film formation surface of the monitor substrate Sm is twice or more, preferably 2 to 3 times the diameter of the bundle fiber, Achieve better measurement accuracy.

In the following, for convenience of explanation, the distance between the front end surface of the optical sensor probe 13 and the film formation surface of the monitoring substrate Sm is referred to as an operation distance WD.

The third difference is that the same monitoring substrate Sm is disposed in the vacuum vessel 1 during the formation of the multilayer film on the actual substrate S, and the multilayer film is also formed on the monitoring substrate Sm. That is, in the present embodiment, the monitoring substrate Sm is not replaced in the middle of forming the multilayer film on the actual substrate S. Further, the film thickness measuring device 6 measures the optical film thickness of each of the films formed on the multilayer film of the monitoring substrate Sm. As a result, when the optical film thickness of each layer of the multilayer film is measured in layers, the influence of the change in the monitoring substrate Sm at each measurement can be suppressed.

Specifically, in the film forming apparatus of the prior art in which the multilayer film is formed, there is a monitor substrate converter (not shown) in which the layers of the multilayer film are formed each time on the actual substrate S. Monitoring the substrate converter replaces the monitoring substrate Sm. However, there is a problem in size, surface state, and processing accuracy between the substrates to be monitored, and there is a case where the measurement accuracy of the film is affected by the unevenness. That is, in terms of reproducibility of film thickness measurement, there is a problem in replacing the monitoring substrate in the middle of formation of the multilayer film.

On the other hand, in the present embodiment, the same monitoring substrate Sm is continuously disposed in the vacuum chamber 1 during the formation of the multilayer film on the actual substrate S. Therefore, the influence of the unevenness between the monitoring substrates Sm does not occur. The accuracy of the measurement of the film is affected. Accordingly, the film thickness of each layer of the multilayer film formed on the monitoring substrate Sm can be measured with good precision, and further, the optical film thickness of the film formed on the actual substrate S side can be controlled with better precision based on the measurement result. .

Further, in the present embodiment, as described above, the annular substrate is used as the monitoring substrate Sm, and on the other hand, the film thickness monitoring device 6 can perform multi-point monitoring. Furthermore, in the present embodiment, the beam-shaped optical fiber has a diameter of about 1.8 mm, and the optical probe 13 is composed of 20 or more irradiation-side fibers f1 and light-receiving fibers f2. As a result, the film thickness measuring device 6 of the present embodiment can set the number of monitoring points (measurement points) to 80 points. In general, for the purpose of improving the light amount sensitivity, two kinds of vapor deposition materials of a high refractive index vapor deposition material and a low refractive index vapor deposition material are formed on the monitoring substrate Sm. Therefore, if the number of monitoring points is 80 points, It is also possible to cope with the case where a multilayer film composed of, for example, 160 layers (80 × 2) is formed.

The fourth difference is that the end surface of each of the irradiation-side fiber f1 and the light-receiving side fiber f2 is disposed on one end surface of the small-diameter portion 25b which is the end surface of the probe 13 for the optical sensor. Specifically, in the present embodiment, each of the end faces of the plurality of irradiation-side fibers f1 disposed on the front end surface of the probe 13 for the optical sensor is adjacent to the end surface of the at least one light-receiving side fiber f2. In the state, it is arranged in an arc shape or an annular shape. In the same manner, each of the end faces of the plurality of light-receiving side fibers f2 is disposed in an arc shape or an annular shape in a state adjacent to each of the end faces of at least one of the irradiation-side fibers f1. .

As described above, when the end surface of the irradiation side fiber f1 and the end surface of the light receiving side fiber f2 are adjacent to each other on the front end surface of the probe 13 for the optical sensor, the incident angle of the light irradiated from the light projector 11 to the film is further reduced. Here, the incident angle is the optical path when the light irradiated from the end surface of the irradiation-side fiber f1 goes to the film, and the light is reflected from the surface of the film or the interface between the substrate Sm and the film to the light-receiving side fiber f2. 1/2 of the angle formed by the light path at the end face.

On the other hand, the relationship shown by the above formula (1) is established between the incident angle θ and the measured value d of the film thickness. Therefore, the larger the incident angle θ, the larger the measurement error Δd of the film thickness. If Physically, when the refractive index of the film-forming material is n=1.47, when the incident angle θ is 3°, 5°, 8°, 10°, and 12°, the measurement error Δd is 0.07. %, 0.2%, 0.5%, 0.7%, 1.0%. On the other hand, the smaller the incident angle θ, the smaller the measurement error Δd of the film thickness.

As described above, the more the end surface of the irradiation-side fiber f1 and the end surface of the light-receiving side fiber f2 are separated, the ratio of the amount of light received by the light-receiving side fiber f2 in the amount of light reflected by the film, that is, the lower the light-receiving efficiency. On the other hand, when the end faces of the irradiation-side fibers f1 and the end faces of the light-receiving-side fibers f2 are adjacent to each other, the light-receiving efficiency is improved.

In addition, since the film thickness measurement accuracy is higher as the filling rate of the optical fiber of the front end surface of the probe 13 for the optical sensor is higher, the end face of the optical fiber is usually disposed in a dense state in the front end surface of the probe 13 for the optical sensor. On the other hand, the denser the end faces of the optical fibers, the more closely the end faces of the irradiation side fibers f1 and the end faces of the light receiving side fibers f2 are denser. In addition, when the end faces of the same type of optical fibers are densely arranged in a block shape, the end faces of the irradiation side fibers f1 and the end faces of the light receiving side fibers f2 are easily separated.

On the other hand, when the end faces of the probes 13 for the optical sensor are arranged such that the end faces of the irradiation-side fibers f1 and the end faces of the light-receiving fibers f2 are arranged in an arc shape or an annular shape, the optical fibers can be efficiently arranged. An optical fiber arrangement in which the irradiation-side fiber f1 and the light-receiving-side fiber f2 are adjacent to each other is realized.

In addition, as the optical fiber arrangement in which the irradiation-side fiber f1 and the light-receiving-side fiber f2 are adjacent to each other, an arrangement may be considered in which the end face of the optical sensor probe 13 and the end face of the irradiation-side fiber f1 and the light-receiving side fiber are disposed. The end faces of f2 are respectively formed into rows, and the rows of various types of optical fibers are alternately arranged. However, in the case where the end faces of the optical fibers are arranged in a dense state in the front end surface of the optical sensor probe 13 in the above-described reason, the end faces of the irradiation side fibers f1 and the end faces of the light receiving side fibers f2 are respectively formed. It is difficult to physically implement a fiber arrangement that is alternately arranged in a row and various types of optical fibers. Therefore, it is preferable to arrange the optical fibers in such a manner that the end faces of the various types of optical fibers are arranged in an arc shape or an annular shape as in the present embodiment.

By the above action, the film thickness measuring device 6 of the present embodiment can measure the optical film thickness with better precision than the conventional device.

Next, a specific example of the arrangement positions of the end faces of the respective sides of the irradiation side fiber f1 and the light receiving side fiber f2 of the front end surface of the probe 13 for the optical sensor will be described with reference to FIGS. 3 to 8 (first to third examples). )Be explained.

3(A) and 3(B) are views showing the arrangement positions of the optical fibers in the first example. Fig. 4 is a view showing the arrangement position of the optical fibers in the comparative example. 5(A) and 5(B) are views showing the arrangement positions of the optical fibers in the second example. Fig. 6 is an explanatory view showing the effectiveness of the arrangement position of the optical fiber of the present embodiment, in which the solid line curve indicates the data of the first example, and the broken line curve indicates the data of the comparative example. 7(A) and (B) are diagrams showing other changes in the second example. 8(A) and 8(B) are views showing the arrangement positions of the optical fibers in the third example. In Figs. 3, 4, 6, 7, and 8, the black circle indicates the arrangement position of the irradiation side fiber f1, and the white circle indicates the arrangement position of the light receiving side fiber f2.

First, as shown in FIGS. 3(A) and (B), the irradiation side fiber f1 and the light receiving side fiber f2 are formed by the irradiation side fiber f1 and the light receiving side fiber f2. Arranged in such a manner that they are arranged in a spiral shape, the bundle is arranged in a circular shape as a whole. In addition, in FIGS. 3(A) and (B), the arrangement position of the irradiation-side fiber f1 and the arrangement position of the light-receiving-side fiber f2 are reversed. Therefore, only the configuration shown in FIG. 3(A) will be described below.

In the first example, as described above, the irradiation side fiber f1 and the light receiving side fiber f2 are respectively Arranged in an arc shape, more specifically in a spiral shape. As a result, in the first example, it is possible to irradiate light to each portion of the effective light-emitting range of the monitoring substrate Sm with a uniform amount of light, and further, it is possible to receive light reflected by the monitoring substrate Sm under uniform conditions.

Further, in the first example, the maximum incident angle is about 8.4°, and the effective incident angle is about 1.5°. Here, the maximum incident angle corresponds to half the angle between the irradiation-side fiber f1 and the light-receiving-side fiber f2 which are farthest from each other before the end face of the optical sensor probe 13, and in FIG. 3(A), it is equivalent to self-positioning The optical path of the light irradiated to the outermost side of the irradiation side fiber f1 is half the angle formed by the optical path of the light to the light-receiving side fiber f2 located at the center of the beam. Further, the effective incident angle corresponds to half the angle between the optical path of the light irradiated from the irradiation side fiber f1 and the optical path of the light that is adjacent to the light receiving side fiber f2 of the optical fiber f1.

When the effectiveness of the arrangement position of the optical fiber of the first example is described, in the first example, the maximum incident angle and the effective incident angle are smaller than those of the comparative example shown in FIG. 4 . More specifically, in the comparative example, the plurality of irradiation-side fibers f1 are arranged in a semicircular shape, and the plurality of light-receiving fibers f2 are arranged in a semicircular shape, and the bundles are arranged in a circular shape as a whole.

Moreover, in the comparative example, the maximum incident angle was about 11.1°, and the effective incident angle was about 6°. Here, the maximum incident angle in the comparative example corresponds to the angle between the optical path of the light irradiated from the outermost irradiation side fiber f1 and the light path to the light of the light receiving side fiber f2 farthest from the optical fiber f1. Half of it. Further, the effective incident angle in the comparative example corresponds to half the angle between the optical path of the light irradiated from the irradiation side fiber f1 at the position of the center of gravity and the light path to the light of the light receiving side fiber f2 located at the center of gravity. Furthermore, the position of the center of gravity refers to the position of the center of gravity of the group of fibers that are semicircular, and when the diameter of the semicircle formed by the group of fibers is r, the relative position of the center of gravity with respect to the center of the semicircle can be (0, 2r). The coordinates of /π) are indicated.

As described above, in the first example, the maximum incident angle and the effective incident angle are smaller than in the comparative example. The reason for this is that in the first example, the degree of scattering of each of the irradiation-side fiber f1 and the light-receiving-side fiber f2 is large, and the ratio of the irradiation-side fiber f1 adjacent to the light-receiving-side fiber f2 and the light receiving is large. The ratio of the side fibers f2 adjacent to the irradiation side fibers f1 is further increased. Therefore, in the first example, the effective light-emitting range is small and the measurement error of the optical film thickness is also small as compared with the comparative example.

Further, in the first example, the relative amount of reflected light (the ratio of the amount of reflected light to the amount of incident light) in the range of 0 to 7 mm in the operating distance WD is further increased with respect to the comparative example. Therefore, in the case where the operating distance WD is in the range of 0 to 7 mm, in the first example, the reflected light can be received with a higher amount of light than in the comparative example. Thereby, the accuracy of the spectroscopic analysis of the spectroscope 14 is improved, and as a result, the measurement accuracy of the optical film thickness is improved.

Next, when the arrangement position of the optical fibers in the second example is described, as shown in FIGS. 5(A) and (B), the irradiation-side fiber f1 and the light-receiving-side fiber f2 are arranged in a ring shape, and the respective optical fibers f1 are arranged. The rings formed by f2 are alternately arranged in a concentric manner. In addition, FIG. 5 (A) and (B) show a configuration in which the arrangement position of the irradiation-side fiber f1 and the arrangement position of the light-receiving-side fiber f2 are reversed, and only the configuration shown in FIG. 5(A) will be described below.

In the second example, as described above, the irradiation-side fiber f1 and the light-receiving-side fiber f2 are arranged in an annular shape, whereby light can be irradiated to each portion of the effective projection range of the monitor substrate Sm with a uniform amount of light. Further, the light reflected by the monitoring substrate Sm can be received under uniform conditions.

Further, in the second example, the maximum incident angle is about 4.2 and the effective incident angle is about 1.5. Further, as shown in FIG. 6, in the second example, the amount of relative reflected light in the range of the operation distance WD of 0 to 7 mm is further increased as compared with the comparative example. Therefore, the action distance WD is 0~7 mm In the case of the second example, the reflected light can be received at a higher light amount than in the comparative example. As a result, the accuracy of the spectroscopic analysis of the spectroscope 14 is improved, and the measurement accuracy of the optical film thickness is improved.

Further, as another variation in which the respective optical fibers are arranged in a ring shape, a configuration may be considered as shown in FIGS. 7(A) and (B), which is located at the outermost side in the ring formed by the irradiation-side fiber f1. In the ring, the irradiation side fiber f1 is replaced with the light receiving side fiber f2 at intervals of about 90°. With this arrangement, in the second example, the difference between the ratio of the ratio of the light-receiving side fibers f2 and the ratio of the irradiation-side fibers f1 in the number of fibers in the bundle is further reduced as compared with the first example. That is, in terms of the function of the probe, it is preferable that the number of the irradiation-side fibers f1 is close to the number of the light-receiving-side fibers f2, and for this reason, the fiber configuration as shown in Fig. 7(A) or (B) may be employed. .

Next, the arrangement position of the optical fiber in the third example will be described. In the third example, each of the irradiation-side fiber f1 and the light-receiving-side fiber f2 is not arranged in an arc shape or an annular shape, and is different from the first and second examples described above. Specifically, in the third example, as shown in FIGS. 8(A) and 8(B), the irradiation-side fibers f1 arranged substantially in a V shape are arranged at five intervals at regular intervals along the outer circumference of the bundle. The light-receiving side fiber f2 is disposed so as to be embedded in the gap and the center of the bundle, and the bundle is arranged in a circular shape as a whole. Moreover, in the third example, the maximum incident angle is about 8.4°, and the effective incident angle is about 1.5°. Therefore, in the third example, compared with the comparative example, the maximum incident angle and the effective incident angle are also small, and the effective projection range is also small. In addition, FIGS. 8(A) and 8(B) show a configuration in which the arrangement position of the irradiation-side fiber f1 and the arrangement position of the light-receiving-side fiber f2 are reversed.

The film thickness measuring device and the film forming device of the present embodiment have been described above. However, the present embodiment is merely an example for facilitating understanding of the present invention, and the members, the arrangement, and the like are not limited to the present invention, and of course, according to the present invention. Various changes and improvements, Further, the equivalents are included in the present invention. For example, the size, size, shape, and material of each device constituting the film measuring device are merely examples for exerting the effects of the present invention, and are not intended to limit the present invention.

Further, in the above-described embodiment, the vacuum deposition apparatus 100 formed by the vacuum deposition method has been described as an example of the film formation apparatus. However, the film formation apparatus formed by the ion plating method and the film formation apparatus are used. The present invention can also be applied to a film forming apparatus formed by ion beam evaporation. Further, the present invention can also be applied to a film forming apparatus using a sputtering method in which ions are collided with a target to form a film.

Further, in the above-described embodiment, in order to improve the light receiving efficiency of the reflected light, the distance between the front end surface of the optical sensor probe 13 and the film formation surface of the monitor substrate Sm, that is, the operation distance WD is set as the bundle fiber diameter. More than 2 times. However, the distance between the front end surface of the probe 13 for the optical sensor and the film formation surface of the monitor substrate Sm may not be twice as large as the diameter of the bundle fiber.

Further, in the above embodiment, an annular substrate is used as the monitoring substrate Sm. The annular substrate is effective, for example, when the measurement of the optical film thickness is performed and the film thickness is measured by a crystal film thickness meter. The reason for this is that, in general, in the film forming apparatus using the annular monitoring substrate Sm, the crystal film thickness gauge can be disposed at the center of the device, specifically equivalent to the substrate holder 2, for the reason of the device structure. Central location. However, the monitoring substrate Sm is not limited to the annular substrate, and may be a substrate of another shape, for example, a disk-shaped substrate.

Further, in the above-described embodiment, the multilayer substrate is formed on the side of the monitoring substrate Sm without changing the monitoring substrate Sm during the formation of the multilayer film of the actual substrate S, but the invention is not limited thereto. That is, the monitoring substrate Sm may be replaced every time each layer of the multilayer film is formed. However, as described above, there is unevenness in size, surface state, and processing accuracy between the substrates to be monitored. When the monitoring substrate Sm is replaced when the film thickness of each layer is changed, the above unevenness affects the measurement accuracy. In this regard, it is desirable that the monitoring substrate Sm is not replaced during the formation of the multilayer film of the actual substrate S.

Further, in the above embodiment, the film forming apparatus for forming a multilayer film on the actual substrate S has been described as an example. However, the present invention is also applicable to an apparatus for forming a single layer film on the actual substrate S.

13‧‧‧Probes for optical sensors

25b‧‧‧Little Trails Department

F1‧‧‧illuminated side fiber

F2‧‧‧light-receiving fiber

Claims (7)

A film thickness measuring device includes: an irradiation device that measures light of an optical film thickness of a film formed on a substrate to be measured, and irradiates light to the substrate to be measured by an optical fiber made of an optical fiber; and a light receiving device: In order to measure the thickness of the optical film, the light-receiving side fiber composed of an optical fiber is received by the substrate to be measured after being irradiated from the irradiation device; and the probe is bundled with the plurality of the irradiation-side fibers. And a plurality of the light-receiving fibers are formed, and an end surface of the plurality of the irradiation-side fibers and the light-receiving side are disposed on a facing surface of the probe that is disposed on a side facing the substrate to be measured The end surface of the fiber is arranged in an arc shape or an annular shape in a state in which the end faces of the plurality of the irradiation side fibers are adjacent to the end faces of the at least one of the light receiving side fibers. Further, each of the end faces of the light-receiving side fibers arranged in a plurality of rows is arranged in an arc shape or an annular shape in a state of being adjacent to each of the end faces of at least one of the irradiation-side fibers. The film thickness measuring device according to the first aspect of the invention, wherein the probe is in a state in which an optical component is not provided between the opposite surface and the substrate to be measured, and the opposite surface and the quilt are The non-film formation surface on the side opposite to the side on which the film was formed in the measurement substrate was opposed to each other. The film thickness measuring device according to claim 2, wherein the plurality of the irradiation side fibers and the plurality of light receiving side fibers constituting the probe are formed as bundle fibers having end faces aligned on the opposite faces, The distance between the opposing surface and the film forming surface is twice or more the diameter of the bundled optical fiber. The film thickness measuring device of claim 3, wherein the substrate to be measured is a disk Shaped or annular substrate. The film thickness measuring device according to any one of claims 1 to 4, further comprising: the illuminating device; a DC stabilized power source: supplying a direct current to a light source provided in the illuminating device; the probe; the beam splitter Providing the light receiving device, and outputting an analog signal corresponding to the received light intensity when the light receiving device receives the light reflected by the substrate for measurement; the amplifier: amplifying the analog signal output from the optical splitter; and the A/D converter : converting the analog signal amplified by the amplifier into a digital signal; the computer: calculating the optical film thickness based on the digital signal; and the signal processing circuit: the A/D converter and the electronic computer When the optical film thickness is calculated by the computer, a specific signal processing is performed on the digital signal. A film forming apparatus for forming a film on a substrate by vapor-depositing a vapor deposition material on a surface of a substrate in a vacuum vessel, comprising: an evaporation mechanism for evaporating the vapor deposition material; and an opening and closing member Opening and closing operations for blocking the evaporation of the evaporation material onto the surface of the substrate; the control mechanism: controlling the opening and closing of the opening and closing member; and claiming any one of items 1 to 5 of the patent scope The film thickness measuring device is in a state in which both the substrate and the substrate to be measured are housed in the vacuum container The evaporation mechanism evaporates the vapor deposition material to vapor-deposit the vapor deposition material on the surfaces of the two, and the film thickness measuring device measures the optical film thickness of the film formed on the substrate for measurement. The mechanism controls opening and closing of the opening and closing member based on the measurement result of the optical film thickness obtained by the film thickness measuring device. The film forming apparatus of the sixth aspect of the invention, wherein the substrate for measurement is disposed in the vacuum container while the multilayer film is formed on the substrate, and the multilayer film is formed on the substrate for measurement The substrate thickness measuring device measures the optical film thickness of each of the multilayer films formed on the substrate for measurement.