JP4701937B2 - Deposition equipment - Google Patents

Description

  The present invention relates to a film formation control method for controlling a film formation state in forming a thin film on a film formation target by evaporating a coating material, a film formation control apparatus suitable for the control method, and a film formation control apparatus. The present invention relates to a film forming apparatus. In particular, the present invention relates to a film formation control method that can detect the state of the coating material more accurately and obtain a high-quality film-formed product.

  2. Description of the Related Art Conventionally, a film forming apparatus that forms a film by depositing an evaporated coating material on the surface of the film forming target is known, for example, a vacuum vapor deposition apparatus that forms a film in a vacuum atmosphere. In addition, when the film formation target is a long plate material or the like as the film formation device, the plate material is continuously supplied into the film formation device, the plate material is run in the device, and the coating material evaporated on the surface is applied. A depositing configuration has been developed. When the film formation target is a long material, it is desired that the film formation apparatus can continuously form a thin film having a uniform thickness in the width direction and the longitudinal direction of the film formation target. In view of this, conventionally, a film formation control apparatus that measures the temperature of the evaporation source that evaporates the coating material during the film formation, the distribution state of the evaporated coating material, and the like, and adjusts the evaporation amount based on the measurement result is formed. It is attached to the membrane device to stabilize the evaporation amount. Typical examples of such a film formation control apparatus include a crystal vibration type, an atomic absorption type, and an electron impact type (see paragraph 0003 of Patent Document 1).

  The quartz vibration type control device arranges a probe made of a crystal resonator in the chamber of the film forming apparatus, directly attaches the evaporated coating material to the probe, and measures the evaporation amount from the change in frequency due to the adhesion of the coating material. . The atomic absorption control device irradiates the evaporating beam (a group of vapors of the coating material toward the film formation target) with specific light, measures the amount of light transmitted through the evaporating beam, and the vapor substance absorbs from this amount of light. The amount obtained is obtained, and the amount of evaporation is measured from this absorbed amount. The electron impact type control device bombards the evaporating beam with an electron beam energized by thermoelectrons from a thermoelectron generator disposed in the chamber, and measures the light intensity of the excitation line excited from the vapor substance. The amount of evaporation is measured from

  Patent Document 1 discloses that a vapor substance is emitted by irradiating a laser beam to an evaporating beam, and this fluorescence is imaged with a CCD camera to form a visible image. The fluorescence intensity is obtained from this image, and the obtained fluorescence intensity is obtained. The space number density distribution of the evaporation beam is acquired from the image, the acquired distribution is compared with the reference distribution, and the temperature of the evaporation source is adjusted based on the result, thereby controlling the film thickness distribution in the width direction of the plate material. Technology is disclosed. Patent Document 2 includes a non-contact type thermometer such as a radiation thermometer or an infrared thermometer, measures the temperature of the evaporation source from the light emitted from the evaporation source, and adjusts the evaporation temperature based on the measured temperature. A vacuum deposition apparatus for performing the above is disclosed.

Japanese Unexamined Patent Publication No. 7-216545 JP 7-331421 A

  Since the crystal vibration type control device directly attaches the evaporated coating material to the probe, there is a limit to the amount of adhesion, and when the film formation rate is high, the film formation state can be detected only for a short time. For example, when a film having a thickness of about 15 μm is formed, if the film formation speed is 50 nm / sec, the crystal oscillation type control device can measure the evaporation amount only for about 5 minutes. When the film formation target is a long material, since it is desired that the film formation state can be detected for a long time, the crystal vibration type control device is not practical.

  On the other hand, the atomic absorption type or electron impact type control device, the control device described in Patent Document 1, the control device described in Patent Document 2, the light transmitted through the window portion provided in advance in the film forming apparatus, This is a configuration in which parameters necessary for adjusting the evaporation amount such as temperature and light intensity are measured based on the light sensed by a light receiving unit arranged outside the film forming apparatus. With this configuration, the light receiving portion is blocked by the window portion and the coating material does not adhere to the light receiving portion, so that light can be sensed for a long time. However, since the window portion is provided at the position facing the evaporation source in the film formation apparatus, the evaporated coating material adheres, and when the film formation time is prolonged, the window portion becomes cloudy due to the adhesion of the coating material, and the transmittance is increased. There is a problem that the received light attenuates and the parameters based on the light cannot be measured correctly. For this reason, the amount of evaporation cannot be accurately controlled, and the quality of the film is deteriorated.

  In order to prevent the coating material from adhering to the window part, it is conceivable to provide the window part at a position where the elevation angle θ from the evaporation source becomes small in the film forming apparatus. It is generally known that the evaporated molecules form a distribution according to the cos θ rule theoretically. For this reason, the density of the evaporated coating material is high at a position where the elevation angle θ is large, and the density of the evaporated coating material is low at a position where the elevation angle θ is small. It becomes difficult for the coating material to adhere to the window portion. However, when the deposition rate is increased, the interaction between the evaporated molecules increases even when θ is small, and the evaporated coating material is likely to adhere to the window. Therefore, it is desired that light from the coating material that has passed through the window can be detected more accurately regardless of the position of the window in the film forming apparatus.

  The present invention has been made in view of the above circumstances, and its main purpose is to control the evaporation amount by detecting light from the coating material that has been transmitted through the window provided in the film forming apparatus. An object of the present invention is to provide a film formation control method capable of detecting detection light with higher accuracy. Another object of the present invention is to provide a film formation control apparatus suitable for this control method. Furthermore, the other object of this invention is to provide the film-forming apparatus provided with this film-forming control apparatus.

  The present invention achieves the above object by obtaining the transmittance of the window portion and correcting the detection light transmitted through the window portion based on the transmittance. The film formation control method of the present invention detects light from the coating material that has passed through the window portion when the coating material is evaporated in a film forming apparatus having a window portion to form a thin film on a film formation target. The evaporation amount is adjusted on the basis of the detection light, and in particular, has the following configuration. The film formation control method of the present invention includes the intensity of the reference light emitted from the light source arranged outside the film formation apparatus and not transmitted through the window, and the transmitted light emitted from the light source and transmitted through the window. The intensity is measured, the intensity of the reference light is compared with the intensity of the transmitted light, the light transmittance of the window portion is obtained, and the detection light is corrected based on the transmittance.

  The above control method of the present invention can be realized by the following film formation control apparatus. The film formation control device of the present invention detects a light from the coating material that has been transmitted through the window portion when the coating material is evaporated in the film formation device having the window portion to form a thin film on the film formation target. And a control unit that adjusts the amount of evaporation based on the detection light. In particular, the present invention has the following configuration. The film formation control apparatus of the present invention includes a light source disposed outside the film formation apparatus, two measurement units for measuring the intensity of light emitted from the light source, and a window unit based on the two measured intensities. A calculation unit that calculates transmittance and a correction unit that corrects the detection light based on the obtained calculation result are provided. Of the two measuring units, one measuring unit (first measuring unit) measures the intensity of the reference light emitted from the light source and not transmitted through the window. The other measurement unit (second measurement unit) measures the intensity of transmitted light that is emitted from the light source, is incident on the window unit, is reflected in the film forming apparatus, and is transmitted through the window unit. Further, the calculation unit calculates the transmittance of the window by comparing the intensity of the obtained reference light and the intensity of the transmitted light.

  The film formation control method of the present invention, and the film formation control apparatus of the present invention that uses this control method, when forming a film with a film formation apparatus that evaporates the coating material and forms a thin film on the film formation target, Control, specifically, for example, adjustment of the amount of evaporation. First, a film forming apparatus and a film forming target will be described. Examples of the film forming apparatus include an apparatus based on the PVD method for forming a film formation target by evaporating the coating material, and examples thereof include a vacuum vapor deposition apparatus for forming a film in a vacuum atmosphere. Such a film forming apparatus includes, as a basic configuration, a holding unit that holds a film forming target, an evaporation source that evaporates a coating material that covers the film forming target, and a chamber in which the holding unit and the evaporation source are stored. Yeah. As the holding portion, various configurations can be used depending on the shape of the film formation target. For example, when the film formation target is a long material, the holding unit continuously supplies the film formation target into the chamber, and the film formation target on which the thin film is formed is discharged out of the chamber. It is preferable that the target is held and the film formation target can be transported from the supply side to the discharge side. The evaporation source is a member that holds the coating material and causes the coating material to be heated and melted by heating means, and a crucible, a Knudsen cell, or the like can be used. Examples of the heating method include electron beam irradiation, resistance heating, induction heating, and the like, and may be appropriately selected according to the material of the coating material, the film formation method, and the like. The chamber is a member that houses the holding unit and the evaporation source and maintains a predetermined atmosphere during film formation. For example, in a vacuum evaporation apparatus, the chamber is a vacuum chamber that can maintain a vacuum state. In the film formation control method and the film formation control apparatus according to the present invention, the amount of evaporation is controlled by detecting light from the coating material that has passed through the window, with respect to the film formation apparatus having the window. Therefore, the film forming apparatus includes a window portion at a position facing the evaporation source. The window portion may be made of a material having resistance to the heat of the evaporation source, characteristic X-rays emitted from the coating material, or the like, for example, a combination of a plurality of glasses made of different materials. Specifically, for example, a combination of a heat-resistant glass having excellent heat resistance characteristics and a lead glass having excellent resistance to characteristic X-rays can be used. The film formation target on which the thin film is formed using such a film forming apparatus may be either a short material or a long material, and the material is a metal material such as copper, steel, cemented carbide, aluminum, or the like. And other materials made of resin materials. Examples of the coating material include metal materials such as aluminum and various alloys, and non-metal materials such as silicon.

  With respect to the film forming apparatus, the control method and the control apparatus of the present invention detect light from the coating material that has been transmitted through the window, and adjust the evaporation amount based on the detected light. Therefore, the control device of the present invention includes a detection unit that detects the detection light transmitted through the window and a control unit that adjusts the evaporation amount based on the detection light. Such a control device of the present invention arranges main constituent members outside the film forming apparatus so that the evaporated coating material scattered in the film forming apparatus does not adhere. The detection unit may appropriately select a configuration according to the detection light, and a basic configuration may include a light receiving unit that receives the detection light and a calculation unit that obtains a parameter such as temperature based on the received light. Examples of the detection light include: 1. Light emitted from the coating material itself without being acted on by the film formation control device; 2. Light emitted from the coating material itself due to specific light emitted from the film formation control device; And light that has been emitted from the film formation control device and transmitted through the evaporated coating material.

  In the case of the detection light described in 1. above, the detection unit receives light emitted from the coating material itself, such as a radiation thermometer, infrared thermometer, and color thermometer, and measures the temperature of the evaporation source in a non-contact manner. It can be mentioned that it can be configured. Since the evaporation amount usually increases with the temperature of the evaporation source, the control unit adjusts the heating means so as to reduce the evaporation amount by lowering the temperature of the evaporation source when the temperature is equal to or higher than a predetermined value. When the temperature is lower than a predetermined value, the heating means may be adjusted so as to increase the evaporation amount by increasing the temperature of the evaporation source. In addition, when the temperature distribution is obtained in the width direction and the longitudinal direction of the film formation target and the temperature distribution varies, it is preferable to adjust the evaporation amount so as to correct the variation.

  In the case of the detection light of 2. above, for example, the detection unit may have an electron impact configuration or a configuration using fluorescence intensity as described in Patent Document 1. In the case of an electron impact type configuration, a thermoelectron generation unit is arranged in the film forming apparatus, and an electron beam energized by accelerating the thermoelectrons emitted from the thermoelectron generation unit is bombarded with a vapor beam. In this case, it is possible to detect an excitation line excited from the evaporated substance and measure the intensity of the excitation line. Since the amount of evaporation usually increases with the magnitude of the intensity, the control unit adjusts the heating means so as to reduce the amount of evaporation when the intensity is greater than or equal to a predetermined value. If it is too low, the heating means may be adjusted to increase the evaporation amount. In addition, when the intensity distribution is obtained in the width direction and the longitudinal direction of the film formation target, and the intensity distribution varies, the control unit may adjust the evaporation amount so as to correct the variation. On the other hand, in the case of a configuration using fluorescence intensity, the detection unit has a laser beam emitting unit arranged outside the film forming apparatus, the laser beam is incident from the window unit and irradiated to the evaporation beam, and the evaporated substance A configuration in which a light receiving unit capable of receiving this fluorescence is arranged outside the film forming apparatus, and the fluorescence intensity is measured from the received fluorescence, and the space number density distribution of the evaporating beam can be measured from this fluorescence intensity. And so on. Then, the control unit may compare the measured distribution with the basic distribution and adjust the heating means so as to approach the basic distribution.

  In the case of the detection light of 3. above, for example, the detection unit may have an atomic absorption type configuration. Specifically, an emission part of light that matches the wavelength of the intrinsic absorption line of the coating material is arranged outside the film forming apparatus, this light is incident on the incident side window part, irradiated to the evaporation beam, and evaporated. A light-receiving unit that can receive light that has been transmitted without being absorbed by the beam and transmitted through the exit-side window is placed outside the film-forming device, and the amount of light absorbed by the evaporated substance (absorption amount) is determined from the amount of transmitted light received. ) And the amount of evaporation of the vapor beam can be measured from this amount of light absorption. When the evaporation amount is equal to or greater than a predetermined value, the control unit adjusts the heating unit to reduce the evaporation amount, and when the evaporation amount is less than the predetermined value, the control unit adjusts the heating unit to increase the evaporation amount. Good. Further, the distribution of the evaporation amount in the width direction and the longitudinal direction of the film formation target is acquired, and when the evaporation amount varies, the control unit may adjust the evaporation amount so as to correct the variation. In the case of this detection unit, the film forming apparatus includes two windows, an incident side window and an emission side window. At this time, the transmittance of the window portion to be described later is obtained at least for the exit-side window portion, and the incident-side window portion may be treated as being similar to the transmittance of the exit-side window portion. You may make it obtain | require both the transmittance | permeability of a side window part. Then, the detection light may be corrected based on the two transmittances.

  The control unit adjusts the evaporation amount based on the temperature of the evaporation source and the evaporation amount obtained by the detection unit as described above. The adjustment of the evaporation amount may include, for example, increasing or decreasing the irradiation amount when the heating means is electron beam irradiation, or increasing or decreasing the energization amount when resistance heating or induction heating is used. An example of such a control unit is to use a computer. In addition, the control unit includes a determination unit that performs determination based on the result obtained by the detection unit, a command unit that issues a command based on the determination result, a storage unit that stores a calculation value, and the like. May be. It is good also as a structure which provides a calculation part in a control part among detection parts. Furthermore, the control unit may be configured not only to control the heating unit but also to control the introduction speed of the film formation target, the light source, the first measuring unit, and the second measuring unit, which will be described later. Note that a monitor may be connected to the control unit so that an operation such as inputting a control condition can be arbitrarily performed. The input operation may be, for example, a touch panel type or an input format using a keyboard. This monitor control may also be performed by the control unit.

  As described above, the film formation control apparatus of the present invention can use the configuration of the conventional control apparatus as a basic configuration. In particular, the control method and the control device of the present invention are characterized in that when measuring predetermined parameters by receiving light (detection light) from a coating material that has been transmitted through a window included in the film forming apparatus, The detection light is corrected according to the transmittance of the window. In order to obtain the transmittance of the window portion, the control method and the control device of the present invention provide a light source outside the film forming apparatus so that the evaporated coating material does not adhere, and uses the light of this light source. An example of such a light source is one that emits laser light. Such a light source is preferably provided with at least one, and in order to obtain reference light and transmitted light, which will be described later, one light source may be used in common, or two light sources with similar specifications may be provided, One light source may be used for reference light and the other light source may be used for transmitted light.

  In the control method and control device of the present invention, the light emitted from the light source and not transmitted through the window is used as reference light, and the light emitted from the light source and transmitted through the window is used as transmitted light. The intensity of the light and the intensity of the transmitted light are measured, and these two intensities are compared to determine the transmittance. Since the reference light does not pass through the window portion, it is not affected by the coating material attached to the window portion, and the intensity when emitted from the light source is substantially maintained. On the other hand, since the transmitted light is transmitted through the window portion, when the coating material is attached to the window portion, the transmitted light is attenuated and reduced in intensity than the light emitted from the light source. These intensity differences are expressed as transmittance. For example, the transmittance may be obtained from the ratio of the intensity of the transmitted light to the intensity of the reference light, that is, the intensity of the transmitted light / the intensity of the reference light. In order to obtain such transmittance, the control device of the present invention includes, in addition to the light source, a first measurement unit that measures the intensity of reference light, a second measurement unit that measures the intensity of transmitted light, and two intensities. And a calculation unit for calculating the transmittance.

  The transmitted light is basically light transmitted through the same window as the window where the light from the light source is incident, except when the incident-side window and the exit-side window are provided. And In order to emit light incident on the window part from the same window part, for example, a reflection part may be provided in the film forming apparatus. The reflection unit may use a mirror or the like.

  Each of the first measurement unit and the second measurement unit includes a configuration including a light receiving unit (photo detector) that receives reference light and transmitted light, and a calculation unit that obtains intensity based on the received light. When receiving reference light and transmitted light from light emitted from one light source, a semi-transmissive part such as a half mirror is arranged between the light source and the first measurement part, and the first measurement part is semi-transmissive from the light source. The second measurement unit is configured to detect the light that is reflected by the semi-transmissive part and incident on the window part, reflected by the film forming apparatus, and transmitted through the window part. Can be mentioned. With such a configuration, the light emitted from one light source can be branched into two, and the intensity of these two lights can be measured by each measurement unit.

  Based on the obtained transmittance, the control method and the control device of the present invention correct light (detection light) from the coating material that has been transmitted through the window provided in the film forming apparatus. In performing the correction, the control device of the present invention includes a correction unit that corrects the detection light. As described above, when the coating material adheres to the window portion, the transmittance of the window portion changes, specifically, the transmittance decreases, so that the detection light is attenuated, and the temperature obtained based on this detection light. There is a possibility that a predetermined parameter such as the above may differ from an actual value. For example, when a parameter such as temperature is measured to be small, there is a possibility that the amount of evaporation is misunderstood although it is not due to a decrease in the amount of evaporation but due to the attenuation of the detection light. Therefore, it is necessary to appropriately determine the transmittance of the window portion and correct the amount of attenuation based on the transmittance. Therefore, in the present invention, the transmittance of the window portion is obtained, and the detection light is corrected according to the transmittance. With this configuration, the present invention can measure a predetermined parameter such as temperature more accurately, can adjust the evaporation amount more accurately based on the measurement result, and can more reliably stabilize the evaporation amount. . The correction includes, for example, compensating for an attenuation amount based on the transmittance as an electric signal. The calculation unit and the correction unit may use a computer. You may use in common with the computer used as said control part.

When the film forming state is controlled by the control device of the present invention having the above-described configuration, for example, a computer having a program having the following steps may be executed.
1. Step of measuring the intensity of the reference light by the first measuring unit and measuring the intensity of the transmitted light by the second measuring unit
2. Step of calculating the transmittance of the window by comparing the intensity of the measured reference light and the intensity of the transmitted light by the calculation unit
3. Step of detecting light from the coating material by the detector
4. The determination unit compares the magnitude relationship between the transmittance and the set value, and when the transmittance is smaller than the set value, the correction unit corrects the detection light.
5. A step of calculating a parameter necessary for adjusting the evaporation amount by the detection unit based on the detected detection light or the corrected detection light.
6. The determination unit determines whether or not the obtained parameter satisfies a predetermined range. If the parameter does not satisfy the predetermined range, the control unit increases or decreases the evaporation amount according to the adjustment value.

  The film formation control apparatus described above may be provided in the existing film formation apparatus, or a film formation apparatus including the film formation control apparatus may be constructed. As a film forming apparatus, for example, a holding unit that holds a film formation target, an evaporation source that evaporates a coating material that covers the film formation target, a chamber in which the holding unit and the evaporation source are disposed, and that has the window And a configuration including the control device of the present invention. In particular, when the film formation target is a long material, the film formation apparatus preferably has a configuration capable of continuously supplying the film formation target into the chamber. For example, the holding unit holds the film formation target. In addition, a configuration in which a film formation target can be transported in the chamber can be mentioned. In addition, in the case where the film formation apparatus is a vacuum evaporation apparatus that performs film formation in a vacuum atmosphere, a vacuum chamber capable of maintaining a vacuum state is preferably used as the chamber. Such a film forming apparatus of the present invention can adjust the evaporation amount based on the detection light transmitted through the window by providing the film forming control apparatus. In particular, since the transmittance of the window is obtained by the film formation control apparatus of the present invention and the detection light is corrected, it is possible to more accurately measure a predetermined parameter such as temperature, and as a result, adjust the evaporation amount. Can be performed more accurately.

  In determining the transmittance, the control device of the present invention detects the transmitted light that is emitted from the light source, incident on the window, reflected in the film forming apparatus, and transmitted through the window. Therefore, the film forming apparatus of the present invention is provided with a reflecting portion such as a mirror so that incident light from the light source can be reflected.

  In the present invention, the transmittance is obtained as described above, and the detection light is corrected by this transmittance. Therefore, even if the coating material is attached to the window provided in the film forming apparatus, the predetermined parameter is accurately obtained. Measurements can be made. However, it is desirable that the coating material is not attached to the window as much as possible. Accordingly, the film forming apparatus can face the evaporation source from the window only when detecting the detection light and calculating the transmittance. When the above detection is not performed, the coating material does not adhere to the window. It is preferable to adopt a simple configuration. For example, a shutter part that can be opened and closed is provided between the window part and the evaporation source, and when performing the above detection, the shutter part is opened so that light from the light source can be incident on the window part and further incident. When the light reflected from the reflective part is transmissive and the light from the coating material is transmissive, and when the above detection is not performed, the shutter part is closed, so that the window part and the evaporation source For example, the gap may be blocked to prevent the coating material from adhering to the window. In particular, this shutter part is preferably arranged so that the coating material does not adhere to the reflection part. Specifically, since the reflection portion is disposed between the window portion and the evaporation source, the shutter portion is disposed between the reflection portion and the evaporation source, so that when the shutter portion is closed, the window portion and It is possible to prevent the coating material from adhering to both of the reflection portions. By providing such a shutter portion, the film forming apparatus of the present invention can adjust the evaporation amount for a longer period.

  According to the present invention, which has a configuration in which the transmittance of the window portion used for observing the film formation state is obtained and the detection light transmitted through the window portion is corrected by this transmittance, the evaporated coating material is attached. Even if the window is cloudy, it is possible to more accurately measure the parameters necessary for adjusting the evaporation amount obtained based on the detection light. Therefore, the evaporation amount can be more reliably stabilized by applying the present invention in film formation. Further, in the present invention, since the main constituent member used for film formation control is provided outside the film formation apparatus, the evaporation amount can be adjusted over a long period of time. Therefore, even when the film formation target is a long material such as a plate material, the film formation state is stable over a long period of time by using the present invention. Variation in thickness in the width direction and length direction can be reduced, so that a uniform thin film can be formed in the same width direction and length direction, and a high-quality film is provided. Can do.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a film forming apparatus including the film forming control apparatus of the present invention, and FIG. 2 is a functional block diagram of the film forming control apparatus of the present invention.

  The film formation control apparatus of the present invention is provided along with the film formation apparatus 100 to control the film formation state of the film formation target 200. First, the film forming apparatus 100 will be described. This film forming apparatus 100 is a vacuum vapor deposition apparatus that deposits a coating material on a film formation target 200 in a vacuum atmosphere. A vacuum chamber 101 that can be evacuated and can maintain a vacuum state is disposed in the chamber 101. And a crucible (evaporation source) 102 for heating and melting and evaporating the coating material, and a heating means 103 for heating the coating material in the crucible 102. In this example, the film formation target 200 is a long plate material, and the film is continuously introduced into the chamber 101 from the supply port configured to be able to hold the chamber 101 in a vacuum during film formation, and the coating is evaporated. Material is deposited on the surface to form a thin film. The film formation target 200 covered with the thin film is discharged from a discharge port configured to be able to hold the inside of the chamber 101 in a vacuum, like the supply port. In order to introduce and discharge such a film formation target 200 into and out of the chamber 101, a delivery mechanism (not shown) for sending the film formation target 200 to a supply port and a thin film are formed outside the film formation apparatus 100. A winding mechanism (not shown) for winding the film formation target 200 discharged from the discharge port is provided, and the introduced film formation target 200 is held in the film formation apparatus 100 and from the supply port to the discharge port. A transport unit 104 for transporting The transport unit 104 is disposed on the back side of the film formation target on which the thin film is not formed, and is a rotatable cylindrical roller unit 104a, and a pair of curved pieces 104b that hold the surface side of the film formation target on which the thin film is formed. With The heating means 103 is configured to use an electron gun (electron beam device) and adjust the output by the power source 103a. The power source 103a is controlled by the control unit 50. As the control unit 50, a computer including a determination unit, an instruction unit, a storage unit, a calculation unit, and the like was used. In addition, a monitor 60 is connected to the control unit 50 so that an operation such as inputting a control condition can be arbitrarily performed.

  The film forming apparatus 100 is disposed so as to cover the crucible 102, and includes an adhesion preventing plate (not shown) having an opening of a predetermined size, and an opening / closing part (not shown) for opening and closing the opening. In addition, the evaporated coating material passes through the opening and adheres to the film formation target 200 when the opening / closing part is opened. By adjusting the size of the opening, the supply speed of the film formation target 200, the film formation speed, etc., a thin film having a desired thickness can be formed uniformly in the width direction and the longitudinal direction of the film formation target 200. it can. The control of the opening / closing operation of the opening / closing unit may be performed by the control unit 50.

  Further, the chamber 101 of the film forming apparatus 100 is provided with a window portion 105 at a position facing the crucible 102, and a film forming control device to be described later is observed by observing the molten state (temperature) of the coating material through the window portion 105. Thus, the film forming state is controlled. In this example, a cylindrical portion 106 having both ends opened to the outside of the chamber 101 is provided, one end is opened toward the crucible side, and a window portion 105 is provided to close the other end opening. The window portion 105 is configured by combining heat resistant glass and lead glass in consideration of heat resistance and the influence of characteristic X-rays. In the cylindrical portion 106, a reflecting portion 107 made of a mirror is disposed at a predetermined position.

  In this example, it is assumed that the electrode material of the lithium secondary battery (configuration having an active material layer on the current collector) is used as the film formation, and the current collector is the film formation target and the active material layer is the coating material. Material was used. Specifically, copper foil was used as the current collector, and silicon was used as the material for forming the active material layer.

  Next, the film formation control apparatus will be described. The film formation control apparatus includes a detection unit 10 that detects light emitted from the coating material in the crucible 102, and a control unit 50 that adjusts the evaporation amount based on the detected detection light. In this example, in order to prevent adhesion of the coating material, heat insulation with the chamber 101 that is a high temperature environment, and prevention of damage due to a pressure difference with the chamber 101 that is a high pressure environment, a film formation control device is provided outside the film formation device 100. It is arranged. As shown in FIG. 2, the detection unit 10 includes a light receiving unit 11 that receives light emitted from the coating material in the crucible 102, and a main calculation unit 12 that measures the temperature in the crucible 102 based on the received light. With The light receiving unit 11 includes three photodetectors A to C, and each of the photodetectors A to C includes a filter 13 in front of the detection direction. The filters 13 are color glasses having different colors. With these filters 13, the photodetectors A to C receive light of different colors, that is, light of different wavelengths, from the light from the coating material. These lights pass through the cylindrical portion 106 included in the vacuum chamber 101, pass through the window portion 105 and the filter 13, and are received by the photodetectors A to C, respectively. The main calculation unit 12 measures the temperature in the crucible 102 based on the light output ratio obtained from each of the photodetectors A to C. The control unit 50 includes a first determination unit 51. The first determination unit 51 determines whether the obtained temperature is within a predetermined range. As a result of the determination, the measured temperature is out of the predetermined range. In this case, in order to adjust the temperature of the crucible 102, the output of the power source 103a of the electron gun 103 provided in the film forming apparatus 100 is adjusted. Specifically, for example, when the temperature is lower than the lower limit value of the predetermined range, the crucible 102 has a low temperature and a small evaporation amount. Therefore, the control unit 50 increases the output of the electron gun 103 in order to increase the temperature of the crucible 102 in order to increase the evaporation amount. On the other hand, when the temperature is higher than the upper limit of the predetermined range, the temperature of the crucible 102 is high and the evaporation amount is large. Therefore, the control unit 50 reduces the output of the electron gun 103 in order to lower the temperature of the crucible 102 in order to reduce the evaporation amount. As described above, the film forming apparatus 100 includes the film forming control apparatus and adjusts the evaporation amount, so that a uniform thin film can be stably formed in the width direction and the longitudinal direction of the film forming target.

  The film formation control apparatus shown in this example is based on the coating material transmitted through the window 105 included in the film formation apparatus 100 as described above in controlling the film formation state (specifically, the temperature of the crucible 102). The light is used. Since the window portion 105 is arranged so as to face the crucible 102, the evaporated coating material scattered in the chamber 101 passes through the cylindrical portion and adheres to the surface of the window portion 105. When the coating material adheres to the window portion 105, the light from the coating material that has passed through the window portion 105 is attenuated, so that the light received by the photodetectors A to C decreases, and the temperature of the crucible 102 may be measured low. is there. Therefore, the film formation control apparatus shown in this example includes means for measuring the transmittance of the window portion 105 in order to more accurately measure the temperature of the crucible 102 without being affected by the coating material attached to the window portion 105, The light (detection light) received by the photodetector is corrected based on the measured transmittance. Specifically, the intensity of the reference light emitted from the light source 20 arranged outside the film forming apparatus 100 and not transmitted through the window 105, and the transmitted light emitted from the light source 20 and transmitted through the window 105. The intensity is measured, the transmittance of the window 105 is obtained from these two intensities, and the detection light is corrected according to the obtained transmittance. In view of this, the film formation control apparatus shown in this example includes a first measurement unit 21 that measures the intensity of the reference light, a second measurement unit 22 that measures the intensity of the transmitted light, and a transmittance that compares both intensities. And a correction unit 53 that corrects the detection light based on the obtained calculation result.

  The light source 20 uses a laser device capable of emitting laser light, is connected to a power source 23, and the output is adjusted by the power source 23. The power source 23 is connected to the control unit 50 and controlled by the control unit 50. The first measurement unit 21 is a first photodetector 24 that receives light (reference light) emitted from the light source 20 and not transmitted through the window 105, and a first calculation unit 25 that measures the intensity of the received light. With The second measurement unit 22 includes a second photodetector 26 that receives light (transmitted light) emitted from the same light source 20 and transmitted through the window 105, and a second calculation unit 27 that measures the intensity of the received light. With In the film formation control apparatus shown in this example, the first measuring unit 21 is coaxial with the optical axis of the light source 20 in order to efficiently receive the reference light and the transmitted light by the light emitted from the same light source 20. The first photo detector 24 was disposed, and the half mirror 28 was disposed between the light source 20 and the first measurement unit 21. The light transmitted through the half mirror 28 is received by the first photodetector 24, and the light reflected from the half mirror 28 (first reflected light) is transmitted through the window 105 and received by the second photodetector 26. . More specifically, a mirror 29 is arranged between the half mirror 28 and the light source 20, the first reflected light is reflected by the mirror 29, and the reflected light (second reflected light) is sent to the window 105. The second reflected light that has been transmitted and transmitted through the window 105 is reflected by the reflecting unit 107 provided in the film forming apparatus 100, and the reflected light is transmitted through the window 105 and transmitted as the second measuring unit. The light is received by 22 second photodetectors 26. The calculation unit 52 and the correction unit 53 are included in the control unit 50.

  In this example, the half mirror 28 and the mirror 29 are provided. However, two light sources capable of emitting the same laser light are prepared, the laser light from one light source is received by the first photodetector, and the other It is good also as a structure which permeate | transmits the same laser beam radiate | emitted from the light source of the above to a window part, and permeate | transmits the transmitted light from a window part with a 2nd photodetector.

  The calculation unit 52 calculates the transmittance of the window unit 105 by comparing the intensity of the reference light obtained from the first measurement unit 21 and the second measurement unit 22 and the intensity of the transmitted light. Based on the result of the calculation, the second determination unit 54 included in the control unit 50 compares the magnitude relationship between the calculated value and the set value. When the calculated value is smaller than the set value, it is considered that the detection light is attenuated because the coating material is attached to the window portion 105 and the light intensity cannot be measured appropriately in the detection portion 10. Therefore, in this case, the correction unit 53 corrects the detection light based on the calculated value. The detection unit 10 measures the temperature of the crucible 102 based on the corrected detection light, and the control unit 50 controls the film formation state based on the result.

The procedure for controlling the film formation state by using such a film formation control apparatus will be described more specifically. FIG. 3 is a flowchart showing a procedure for controlling the film formation state using the film formation control apparatus of the present invention. First, the control unit includes a light source to provide output instruction, the first measuring unit measuring the intensity S ₁ of the reference light, to perform measurement of the intensity S ₂ of transmitted light in the second measurement unit (step S1). By this command, the first measuring unit receives the reference light emitted from the light source and not transmitted through the window included in the film forming apparatus by the first photodetector, and the intensity of the received reference light is measured by the first calculating unit. measure. Similarly, the second measuring unit emits light from the light source, passes through the window provided in the film forming apparatus, is reflected by the reflecting unit, receives the transmitted light that has passed through the window again by the second photodetector, and transmits the received light. The light intensity is measured by the second calculator. By comparing the two intensities S ₁ and S ₂ obtained, the calculation unit calculates the transmittance μ of the window (step S2). The transmittance μ was the ratio S ₂ / S ₁ between the two intensities S ₁ and S ₂ . The calculated transmittance μ is temporarily stored in the storage unit.

  On the other hand, the control unit issues a command to the detection unit to detect the light emitted from the coating material in the crucible (step S3). By this command, the detection unit receives the light emitted from the coating material in the crucible and transmitted through the window by the three photodetectors, and outputs the three detection lights. Each of the obtained three detection lights is temporarily stored in the storage unit.

  When the detection light is obtained, the control unit calls the transmittance μ from the storage unit, and causes the second determination unit to determine the magnitude relationship between the transmittance μ and the set value x (step S4). In response to this command, the second determination unit calls the set value x set in advance and input to the storage unit, and determines whether or not the transmittance μ satisfies μ ≧ x. When the transmittance μ does not satisfy μ ≧ x, that is, when the transmittance μ is smaller than the set value x, it is considered that the transmittance of the window portion is changed due to adhesion of a coating material or the like. Therefore, if the detection light obtained in step S3 is used as it is, an accurate temperature cannot be measured. Therefore, the control unit instructs the correction unit to correct the three detection lights according to the transmittance μ (step S5). Based on this command, the correction unit obtains the amount of light attenuated by the transmission of the window portion to which the coating material is attached based on the transmittance, and compensates this attenuation as an electrical signal. Further, the control unit instructs the main calculation unit of the detection unit to measure the temperature T from the corrected detection light (step S6). By this command, the main calculation unit compares the three corrected detection lights and obtains a temperature T that is a parameter used for adjusting the evaporation amount. On the other hand, when the transmittance μ satisfies μ ≧ x, the window portion has no or almost no adhesion of the coating material, and the temperature is obtained using the detection light detected by the detection portion as it is. Therefore, the control unit instructs the main calculation unit of the detection unit to measure the temperature T from the three detection lights obtained by the detection unit (step S6).

Next, the film forming state is controlled based on the obtained temperature T. First, the control unit instructs the first determination unit to determine whether or not the temperature T is included in a predetermined range (step S7). In this example, by this command, the first determination unit calls the set temperature T _S and the temperature range (0, t ₁ , 0 <t ₁ ) that are set in advance and input to the storage unit, and 0 ≦ TT _S It was determined configure whether satisfy ≦ t _1. It is preferable that the temperature T has no deviation from the set temperature T _S , that is, TT _S = 0. Therefore, the heating means of the coating material is adjusted (in this example, adjustment of the output of the electron gun) so that the deviation approaches O, that is, the difference between the two temperatures is 0 or more and t ₁ or less, and the evaporation amount adjust.

If the temperature T does not satisfy 0 ≦ TT _S ≦ t ₁ , it is considered that the temperature T is too high or too low. When the temperature T is too high, the evaporation amount is large, and when the temperature T is too low, the evaporation amount is considered to be small. Therefore, the control unit instructs the first determination unit to determine whether the temperature T is too high or too low (step S8). In this example, the first determination unit is configured to determine whether or not the temperature T satisfies T _S > t ₁ by this command. When the temperature T satisfies TT _S > t ₁ , the temperature T is higher than the set temperature T _S. That is, the temperature of the crucible is too high. Therefore, the control unit instructs the power source of the electron gun to reduce the evaporation amount, and reduces the output according to the temperature T (step S9). When the temperature T does not satisfy TT _S > t _1, that is, when TT _S <t ₁ , the temperature T is smaller than the set temperature T _S , that is, the temperature of the crucible is too low. Therefore, the control unit instructs the power source of the electron gun to increase the evaporation amount, and increases the output according to the temperature T (step S10).

When the temperature T satisfies 0 ≦ TT _S ≦ t ₁ , the temperature T is at an appropriate temperature, and it is considered unnecessary to change the evaporation amount. Therefore, the first determination unit determines that there is no change (step S11). After this determination and when the evaporation amount adjustment operation is completed, the film forming state can be controlled for a long time by configuring the control unit to repeat the procedure from step S1. Further, this control procedure may be performed continuously, or a timer unit may be provided in the control unit, and may be performed every predetermined time, that is, intermittently.

  By using the film formation control device, even if a coating material adheres to the window portion of the film formation device, the detection light is appropriately corrected according to the transmittance of the window portion. Can be measured. Therefore, the film forming apparatus having the film forming control apparatus of the present invention can control the film forming state with higher accuracy and obtain a high-quality film. In particular, even when the film formation target is a long plate material and it is desired to form a thin film having a uniform thickness in the width direction and the longitudinal direction of the film formation target, the control device of the present invention is provided. Therefore, it is possible to provide a film with excellent quality.

  In the above-described example, since there is nothing to block between the window portion and the crucible, the window portion has a high possibility that the evaporated coating material is scattered and the coating material adheres. Therefore, in order to prevent the covering material from adhering to the window portion, a shutter portion 108 that can be opened and closed may be provided between the window portion 105 and the crucible 102 as shown in FIG. When it is not necessary (for example, when the transmitted light or detection light from the window is not acquired, for example, during the operation of adjusting the deposition amount), the shutter 108 is closed to attach the coating material to the window 105. This can be effectively prevented. In particular, as shown in FIG. 1, when the shutter part 108 is provided so that the opening provided on the crucible side in the cylindrical part 106 can be opened and closed, the shutter part 108 is arranged between the reflecting part 107 and the crucible 102. Further, it is possible to prevent the coating material from adhering not only to the window part 105 but also to the reflection part 107.

(Test example)
When the film formation control apparatus as shown in FIG. 1 and a film formation apparatus having a shutter part between the reflection part and the crucible are configured, the shutter part is opened and closed intermittently, and the shutter part is opened. The temperature of the crucible was measured, and the film formation state was controlled by measuring the transmittance with a film formation control device. In this test, the shutter part was opened every 10 minutes. In this test, a film having a thickness of 5.0 μm was formed on a long film formation target having a width of 130 mm. As a result, the film formation state was observed and controlled for a long time of 1.5 hours or longer. Moreover, the obtained film-formed product was uniform in thickness in the width direction and the longitudinal direction, and was high quality. Specifically, the variation in film thickness in the width direction and length direction could be suppressed to within ± 8.0%. From this test result, it was confirmed that a high-quality film can be obtained over a long period of time by controlling the film formation state with the film formation control device of the present invention.

  The film formation control method and the film formation control apparatus of the present invention can be suitably used to control the film formation state (evaporation amount, etc.) when forming a thin film on the film formation object by the film formation apparatus. In addition, the film forming apparatus including the film forming control apparatus of the present invention can perform film formation with high quality over a long period of time, even when the film forming target is a long material. It can be suitably used in the field of film formation.

It is a schematic block diagram of the film-forming apparatus provided with this invention film-forming control apparatus. It is a functional block diagram of a film formation control device of the present invention. It is a flowchart which shows the procedure which controls evaporation amount using this invention film-forming control apparatus.

Explanation of symbols

10 Detector 11 Receiver 12 Main calculator 13 Filter
20 Light source 21 First measurement unit 22 Second measurement unit 23 Power supply
24 First Photodetector 25 First Calculator 26 Second Photodetector
27 Second calculator 28 Half mirror 29 Mirror
50 Control unit 51 First determination unit 52 Calculation unit 53 Correction unit 54 Second determination unit
60 monitors
100 Film deposition equipment 101 Vacuum chamber 102 Crucible 103 Heating means 103a Power supply
104 Conveying section 104a Roller section 104b Curved piece 105 Window section 106 Cylindrical section
107 Reflector 108 Shutter
200 Deposition target

Claims (2)

A film forming apparatus for forming a thin film on a film formation target by evaporating a coating material,
  A vacuum chamber having a window;
  A light source disposed outside the vacuum chamber;
  An evaporation source disposed in the vacuum chamber and evaporating a coating material covering the film formation target;
  A detection unit that detects detection light from the coating material that has passed through the window from the inside of the vacuum chamber to the outside;
  A reflection part that is disposed between the window part and the evaporation source and reflects the light emitted from the light source and incident from the outside of the window part;
  An openable and closable shutter unit disposed between the reflective unit and the evaporation source and preventing the coating material evaporated when closed from adhering to the window unit and the reflective unit;
  A first measurement unit that measures the intensity of the reference light emitted from the light source and not transmitted through the window;
  A second measuring unit that measures the intensity of transmitted light that is emitted from the light source and incident on the window, reflected by the reflecting unit in the vacuum chamber, and transmitted through the window;
  Comparing the intensity of the obtained reference light and the intensity of the transmitted light, a calculation unit for calculating the transmittance of the window part,
  A correction unit that corrects the detection light based on the obtained calculation result;
  A control unit for adjusting the evaporation amount of the coating material based on the corrected detection light;
  A film forming apparatus comprising: The film forming apparatus according to claim 1, further comprising a transfer unit disposed in the vacuum chamber and configured to transfer a long film formation target.

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