JP6218566B2 - Thin film forming apparatus and thin film forming method - Google Patents

Description

The present invention relates to a thin film forming apparatus and a thin film forming method capable of forming an optical thin film including a light absorbing film that attenuates transmitted light over a predetermined wavelength range, such as an absorption ND filter.
In particular, the present invention relates to a thin film forming apparatus for forming a thin film on a film formation target substrate held by a rotating dome-shaped substrate holder, a thin film forming method, and an optical thin film monitoring apparatus used therefor.

ND (Neutral Density) filters include a reflective ND filter that reflects and attenuates incident light and an absorption ND filter that absorbs and attenuates incident light.
An absorption ND filter is generally applied to an optical system in which reflected light is a problem.

As an absorption type ND filter, an ND filter that mixes an absorbing substance with the substrate itself, an ND filter that is applied to the substrate, or an ND filter that has an absorption function on a thin film formed on the substrate surface is known.
In order to prevent reflection on the surface of the thin film, the ND filter having an absorption function in the thin film has a thin film formed of a multilayer film, and has a function of attenuating transmitted light and a function of preventing reflection.

For example, Patent Document 1 discloses an ND filter in which a large number of oxide dielectric layers and metal absorption film layers are alternately stacked.
The optical multilayer film constituting the ND filter has a multilayer structure in which dielectric thin films having different refractive indexes are laminated.
For example, in the ND filter, an optical multilayer film in which a thin film containing Ti or TiO ₂ as an absorption film and a thin film of SiO ₂ as an antireflection film are alternately stacked is formed on an optical substrate such as quartz glass. .

Each thin film constituting the optical multilayer film is formed to have a predetermined optical film thickness.
The optical film thickness is defined by the product of the physical film thickness of the thin film and the refractive index of the thin film, and is an important factor for satisfying the optical characteristics desired for the optical multilayer film.

Examples of the method for forming the optical multilayer film include vacuum deposition such as ion beam assisted vacuum deposition, molecular beam deposition, and ion plating.
Since the refractive index of a thin film depends on the type and composition of the elements that make up the thin film, for example, when forming a thin film by vacuum deposition, a thin film having a desired refractive index can be formed by appropriately selecting the composition of the vacuum deposition source. can do.
Further, in order to obtain a desired optical film thickness in the optical multilayer film having the above-described configuration, it is required to suppress an error from a design value to 0.1% or less as the physical film thickness accuracy of each thin film. . For example, Patent Documents 2 to 4 disclose a method for forming a thin film while monitoring the physical film thickness by an indirect or direct film thickness monitoring method.

FIG. 11A is a diagram schematically showing a configuration of a vacuum deposition apparatus using a direct film thickness monitoring method according to a conventional example.
For example, an exhaust pipe and a vacuum pump (not shown) are connected to the vacuum chamber 110 so that the inside can be reduced to a predetermined pressure.
For example, the first vacuum deposition source 120 is disposed in the vacuum chamber 110 and the first deposition material 121 is accommodated therein, and the second vacuum deposition source 122 is disposed in the interior of the second vacuum deposition source 122. The vapor deposition material 123 is accommodated.

For example, the deposition target substrate 130 is held in the vacuum chamber 110 by a substrate holder so as to be rotatable.
Further, a light projecting unit 141 that projects monitor light L onto the film formation target substrate 130 is provided in the vacuum chamber 110, and a light receiving unit that receives the monitor light L that has passed through the film formation target substrate 130. 150 is provided outside the vacuum chamber 110.

In the first vacuum vapor deposition source 120 and the second vacuum vapor deposition source 122, the vapor deposition material is heated by resistance heating, electron beam heating, laser beam heating, etc., and ejected from the first vacuum vapor deposition source 120 and the second vacuum vapor deposition source 122. When the vapor of the deposited material reaches the surface of the deposition target substrate 130 and solidifies, a thin film of the deposition material is formed on the surface of the deposition target substrate 130.
Here, the optical multilayer film having the above-described configuration can be formed by alternately repeating the deposition of the deposition material from the first vacuum deposition source 120 and the deposition of the deposition material from the second vacuum deposition source 122. .

In the vacuum vapor deposition apparatus of FIG. 11A, the monitor light L is projected from the light projecting unit 141 to the film formation target substrate 130 and is transmitted through the film formation target substrate 130 during the formation of each thin film. The light L is received by the light receiving unit 150, and the change in light transmittance due to interference is captured, thereby monitoring the film thickness of the thin film being formed.
The light projecting unit 141 is configured to project, for example, light guided from a light source (not shown) provided outside the vacuum chamber 110 toward the film formation target substrate 130.
Since the film thickness is monitored by receiving the monitor light L transmitted through the film formation target substrate 130, the film thickness monitoring method having the configuration shown in FIG. 11A is referred to as a direct film thickness monitoring method.

FIG. 11B is a diagram schematically showing a configuration of a vacuum deposition apparatus using an indirect film thickness monitoring method according to a conventional example. Note that in FIG. 11B, the same components as those in FIG. 11A are denoted by the same reference numerals for easy understanding.
For example, an exhaust pipe and a vacuum pump (not shown) are connected to the vacuum chamber 110 so that the inside can be reduced to a predetermined pressure.
For example, the first vacuum deposition source 120 is disposed in the vacuum chamber 110 and the first deposition material 121 is accommodated therein, and the second vacuum deposition source 122 is disposed in the interior of the second vacuum deposition source 122. The vapor deposition material 123 is accommodated.

For example, in the vacuum chamber 110, a plurality of film formation target substrates 130 are held by a dome-shaped substrate holder 131 that can rotate and move.
The monitor substrate 132 is held in the central opening of the substrate holder 131 so that one surface (front surface) is a vapor deposition surface.
Further, by projecting a monitor light L _I against the opposite side of the deposition surface of the monitor substrate 132 (the back side), light emitting and receiving unit 151 for receiving the reflected light L _R from the monitor substrate 132 is provided.

In the vacuum vapor deposition apparatus of FIG. 11B, an optical multilayer film can be formed in the same manner as the vacuum vapor deposition apparatus of FIG.
In the vacuum evaporation apparatus of FIG. 11 (b), during the formation of the thin film, and projecting a monitor light _{L I} to the monitor substrate 132 from the light emitting and receiving parts 151, the reflected light _{L R} from the monitoring substrate 132 The light projecting / receiving unit 151 receives the light and monitors the change in the light reflectance.
To estimate the thickness of the thin film of the film-forming target on a substrate from a change in the reflected light L _R from the monitoring substrate 132 is intended to monitor the thickness of the film thickness monitoring method of the configuration shown in FIG. 11 (b) of the indirect This is called a monitoring method.

  Fig.12 (a) is a principal part schematic diagram of the vacuum evaporation system of Fig.11 (a). The film formation target substrate 130 is rotatably held by the substrate holder, and the monitor light L is projected onto the film formation target substrate 130 from a light projection unit (not shown), and the monitor that has passed through the film formation target substrate 130 The light L is received by the light receiving unit 150.

FIG. 12B is a schematic plan view of the deposition target substrate in FIG. For example, the projection spot SP _L of the monitor light L with respect to the film formation target substrate 130 held by rotation is located in the vicinity of the outer peripheral portion of the film formation target substrate 130. A region R the projected light spot SP _L on the deposition target substrate 130 traces becomes good distribution region.

JP 05-93811 A JP 2003-82462 A JP 2002-340527 A JP 2002-303510 A

  However, in the case of using the vacuum deposition apparatus by the direct film thickness monitoring method shown in FIG. 11A, the film is formed by holding one film formation target substrate on the substrate holder. There is a disadvantage that mass production is difficult.

In addition, in a vacuum deposition apparatus using a direct film thickness monitoring method, when an optical filter that does not include an absorption film is produced, a plurality of small peaks appear in the temporal change in the light transmittance of the monitor light. It corresponds to each layer of the corresponding thin film, and the thickness of each layer can be monitored by monitoring the light transmittance.
However, since the above-described absorption type ND filter includes an absorption film formed of a non-oxidized metal oxide film, the first layer is laminated in the change in light transmittance as shown in FIG. In this case, the first peak appears, but the next peak does not appear (cannot be seen) even if a thin film is laminated thereafter, so there is a disadvantage that the optical film thickness cannot be monitored.

In the vacuum deposition apparatus using the indirect type film thickness monitoring method shown in FIG. 11B, a large number of deposition target substrates are held on a dome-shaped substrate holder, and an optical multilayer film is deposited on the numerous substrates simultaneously. Therefore, it is suitable for mass production of optical thin films.
Further, according to the indirect type film thickness monitoring method, since the film thickness of the thin film on the film formation target substrate is estimated and monitored from the change in the reflected light from the monitor substrate, the ND filter including the absorption film is also used. It is possible to monitor an optical thin film.

However, when an absorption type ND filter is manufactured using a vacuum deposition apparatus based on an indirect film thickness monitoring method corresponding to mass production as described above, there are the following disadvantages.
That is, the method of estimating and monitoring the film thickness of the thin film on the deposition target substrate from the change in the reflected light on the surface (back surface) opposite to the vapor deposition surface of the monitor substrate 132 limits the control accuracy of the thin film thickness. Therefore, it is difficult to manufacture an optical multilayer film having a desired transmission band with a high yield.

One reason for this is thought to be that the reflectance on the back surface of the ND filter is highly wavelength-dependent.
For example, the reflectance of the back surface is about 10% in the wavelength range of 350 nm to 550 nm, whereas the reflectance of the back surface increases from about 10% to about 20% in the wavelength range of 550 nm to 800 nm. The change (variation) in reflectance depending on the wavelength limits the accuracy of thin film thickness control, making it difficult to manufacture optical multilayer films having a desired transmission band with a high yield. It is done.

  The above problem is not limited to the ND filter, but is common to all optical filters in which it is important to control the film thickness with high accuracy.

On the other hand, the reflectivity on the surface on the vapor deposition surface side of the ND filter is as small as about 1% to 5% in the above-described wavelength range of 350 nm to 800 nm.
Therefore, by adopting a method of estimating and monitoring the film thickness of the thin film on the film formation target substrate from the change in the reflected light on the vapor deposition surface side (front surface) of the monitor substrate 132, the control accuracy of the film thickness of the thin film is adopted. Therefore, it becomes possible to manufacture an optical multilayer film having a desired transmission band with a high yield.

In this case, for example, as shown in FIG. 14, the optical system forms a large through hole 111 for allowing light to pass through on the lower surface side of the chamber 110, and the light source 170 and the reflection mirrors 171, 172 are formed outside the lower surface side of the chamber 110. The light receiving unit 173 is arranged.
However, in this case, there are disadvantages that the optical path length is long and it is difficult to stabilize optically and over time, and the optical system becomes large, resulting in high cost.

  Further, in the method of estimating and monitoring the film thickness of the thin film on the film formation target substrate from the change in the reflected light on the vapor deposition surface side (surface) of the monitor substrate 132, the film formation is performed while monitoring the film thickness. Although it is possible, it is difficult to monitor the progress of the reaction during film formation.

  The present invention can improve the yield in a vacuum film forming process for manufacturing an optical thin film while suppressing an increase in size and cost of an optical system while supporting mass production even if an absorption film is included. It is another object of the present invention to provide a thin film forming apparatus and a thin film forming method capable of monitoring the progress of the reaction during film formation as required.

  A thin film forming apparatus according to a first aspect of the present invention includes a film formation chamber, a film formation material supply unit disposed in the film formation chamber, and a plurality of film formation target substrates disposed in the film formation chamber. Is held so that the film-forming surface faces the film-forming material supply unit side, and has a dome shape or a flat disk shape, and is rotated around the top of the dome or the center of the flat disk as a rotation center And a light projecting unit that projects monitor light onto the film formation target substrate held on the outer periphery of the substrate holder, and of the monitor light, reflected on the surface side that is a film formation surface of the film formation target substrate A first light-receiving unit that receives the reflected monitor light and outputs a first light-receiving signal; a trigger signal output unit that outputs a trigger signal synchronized with the rotation of the substrate holder; the first light-receiving signal and the trigger signal Perform predetermined signal processing based on And a signal processing unit that acquires the change information of the reflected monitor light of the film-forming target each substrate.

  Preferably, the signal processing unit further includes a second light receiving unit that receives transmission monitor light transmitted to the back side of the film formation target substrate and outputs a second light reception signal. Then, predetermined signal processing based on the second light receiving signal and the trigger signal is performed to obtain change information of the transmission monitor light for each film formation target substrate.

  Preferably, the signal processing unit generates information for estimating and monitoring a film thickness of the thin film on the film formation target substrate based on change information of the reflection monitor light on the surface side of the film formation target substrate. To process.

Preferably, the signal processing unit generates information for estimating and monitoring a film thickness of the thin film on the film formation target substrate based on change information of the reflection monitor light on the surface side of the film formation target substrate. And processing is performed so as to generate information for monitoring the progress of the reaction during the deposition of each film based on the change information of the transmitted monitor light transmitted to the back side of the deposition target substrate.

Preferably, the signal processing unit can perform processing according to a mode, and in the first mode, the film formation target substrate is based on change information of the reflection monitor light on the surface side of the film formation target substrate. Processing to generate information for estimating and monitoring the film thickness of the thin film on the top, and in the second mode, based on the change information of the transmitted monitor light transmitted to the back side of the film formation target substrate Processing is performed so as to generate information for estimating and monitoring the thickness of the thin film on the deposition target substrate.

Preferably, in the first mode, the signal processing unit is in a progress state of a reaction during film formation based on change information of the transmission monitor light transmitted to the back surface side of the film formation target substrate. Process to generate information to monitor.

  The thin film forming method according to the second aspect of the present invention has a film forming material supply section and a dome-like shape or a flat disk shape inside, and is rotated around the top of the dome or the center of the flat disk as a rotation center. A plurality of deposition target substrates are held on the substrate holder of the deposition chamber in which the substrate holder is disposed so that the film formation surface faces the deposition material supply unit, and the top of the dome or the center of the flat disk is positioned. A step of rotating as a center of rotation, a step of supplying a film forming material from the film forming material supply unit to form a film of the film forming material on the substrate to be formed, and an outer peripheral portion of the substrate holder. Projecting the monitor light onto the film formation target substrate, and receiving the reflected monitor light reflected on the surface side, which is the film formation surface of the film formation target substrate, of the monitor light to receive the first light reception signal And the rotation of the substrate holder. A and a step of acquiring a trigger signal, and a step of obtaining the first light receiving signal and the said change information of the reflected monitor light by performing predetermined signal processing based on the trigger signal the film-forming target each substrate.

  An optical thin film monitoring apparatus according to a third aspect of the present invention is disposed in a film formation chamber, holds a plurality of film formation target substrates so that the film formation surface faces the film formation material supply unit, and has a dome shape. A light projecting unit that projects monitor light onto the film formation target substrate held on the outer periphery of the substrate holder that has a shape or a planar disk shape and is rotated around the top of the dome or the center of the planar disk A first light receiving unit that receives reflected monitor light reflected from the surface of the film formation target substrate, which is a film forming surface, of the monitor light, and outputs a first light reception signal; and rotation of the substrate holder A trigger signal output unit that outputs a trigger signal synchronized with the signal, and performs predetermined signal processing based on the first light reception signal and the trigger signal to obtain change information of the reflection monitor light for each film formation target substrate A signal processing unit.

  According to the present invention, in a vacuum film forming process for manufacturing an optical thin film, even if an absorption film is included, the yield is improved while suppressing the increase in size and cost of the optical system while supporting mass production. Is possible. Further, the progress of the reaction during film formation can be monitored as necessary.

FIG. 1 is a diagram schematically showing a configuration example of an ion beam assisted vacuum deposition apparatus according to an embodiment of the present invention. 2A is a schematic diagram of a main part of the vacuum vapor deposition apparatus of FIG. 1, and FIG. 2B is a schematic plan view of a film formation target substrate in FIG. FIG. 3 is a schematic cross-sectional view of an absorption ND filter manufactured by the vacuum film forming apparatus according to this embodiment. FIG. 4 is a diagram showing a monitor example of the progress of the reaction during the formation of each film of the optical filter (ND filter) including the absorption layer (light absorption film) by the transmission monitor light in this embodiment. FIG. 5 is a diagram showing a monitor example of a progress state of a reaction when a predetermined dielectric film of an optical filter (ND filter) is formed by transmission monitor light in the present embodiment. FIG. 6 is a diagram for explaining an example of signal processing according to the vacuum deposition apparatus of the present embodiment. FIGS. 7A and 7B are schematic views of the main part of the vacuum vapor deposition apparatus of FIG. FIG. 8 is a flowchart for explaining a method of producing an optical thin film such as an absorption ND filter in the vacuum film forming apparatus of this embodiment. FIGS. 9A and 9B are schematic views of main parts of a modification of the vacuum vapor deposition apparatus of FIG. FIG. 10 is a flowchart for explaining a monitor control function of a chemical reaction when an optical thin film is produced in the present embodiment. FIG. 11A and FIG. 11B are diagrams schematically showing a configuration of a vacuum deposition apparatus according to a conventional example. 12A is a schematic diagram of a main part of the vacuum vapor deposition apparatus of FIG. 11A, and FIG. 12B is a schematic plan view of the film formation target substrate in FIG. FIG. 13 is a diagram showing a change in light transmittance at the time of forming each film of the absorption ND filter including an absorption film formed of a non-oxidized metal film that is not completely oxidized. FIG. 14 is a schematic configuration example of a vacuum deposition apparatus in a case where a method of estimating and monitoring the thickness of a thin film on a deposition target substrate from a change in reflected light on the surface (surface) on the deposition surface side of the monitor substrate is employed. FIG.

  Embodiments of a vacuum film forming apparatus as a thin film forming apparatus of the present invention and a vacuum film forming method as a thin film forming method using the same will be described below with reference to the drawings.

[Configuration of vacuum deposition system]
FIG. 1 is a diagram schematically illustrating a configuration example of an ion beam assisted vacuum deposition apparatus which is a vacuum film forming apparatus according to the present embodiment.
For example, an exhaust pipe 11 and a vacuum pump 12 are connected to a vacuum chamber 10 that is a film forming chamber, and the inside can be reduced to a predetermined pressure. The back pressure in the vacuum chamber 10 during film formation by vacuum deposition is, for example, about 10 ⁻² to 10 ⁻⁵ Pa.

For example, a first vacuum vapor deposition source 20 is arranged as a film forming material supply unit 200 on the lower side of the inside of the vacuum chamber 10, and the first vapor deposition material 21 is accommodated in the first vacuum vapor deposition source 20. A source 22 is disposed and a second vapor deposition material 23 is accommodated therein.
First deposition material 21 is, for example, SiO _2, the second deposition material 23 is, for example, Ti, TiO ₂ and the like.
When an absorption type ND filter is manufactured, for example, SiO ₂ is selected as the antireflection film for the first vapor deposition material 21, and for example, Ti, TiO ₂ or the like is selected as the absorption film for the second vapor deposition material 23.

  Each vacuum deposition source is provided with heating means such as resistance heating, electron beam heating, and laser beam heating (not shown). When the deposition material is heated and vaporized in the vacuum deposition source, vapor of the deposition material is ejected. .

For example, the substrate holder unit 300 is disposed on the upper side in the vacuum chamber 10. The substrate holder unit 300 has a plurality of film formation target substrates 30 in the direction in which the vapors of the vapor deposition materials of the first vacuum vapor deposition source 20 and the second vacuum vapor deposition source 22 are ejected, and the film formation surface is on the film material supply unit 200 side. A substrate holder 31 that has a dome shape and is rotated around the top of the dome as a rotation center is provided.
For example, the substrate holder 31 is rotatably supported by the holder support portions (32, 33), and is rotationally driven by driving a motor 34 installed outside the vacuum chamber 10.

  For example, when vapor of the vapor deposition material ejected from each vacuum vapor deposition source reaches the surface of the film formation target substrate 30 and solidifies, a thin film of the vapor deposition material is formed on the surface of the film formation target substrate.

For example, the ion source 24 for irradiating the film formation target substrate 30 with ions such as oxygen ions is provided in the vacuum chamber 10, and ion beam assisted vacuum deposition can be performed.
By irradiating the film forming surface of the film formation target substrate 30 with ions from the ion source 24, a film is formed by the vapor deposition material supplied from the film formation material supply unit 200 and the film thickness is increased. It is possible to form a film while a part of the area near the surface of the film is sputtered by ions irradiated from the ion source 24 and the process of reducing the film thickness is simultaneously performed.
At this time, in the case where a film thickness difference occurs depending on the density distribution of the film forming material supplied from the film forming material supply unit 200 in the surface of the film formation target substrate 30, a condition for canceling the film thickness difference By performing sputtering using ions irradiated from the ion source 24, a multilayer film having a uniform in-plane film thickness distribution can be obtained.

For example, a light projecting unit 400 configured to project the monitor light L onto the film formation target substrate 30 held on the outer periphery of the substrate holder 31 is provided.
The light projecting unit 400 is provided in the vacuum chamber 10 with the light source 40 installed outside the vacuum chamber 10, for example, and projects the light from the light source 40 onto the film formation target substrate 30 as the monitor light L to form a film. There is a light projecting head 41 that acquires the reflected light from the target substrate 30 separately from the monitor light L.
Further, the light projecting unit 400 includes a light projecting optical system 42 such as an optical fiber that transmits light from the light source 40 to the light projecting head 41, a light projecting head support unit 43 that supports the light projecting head 41, and the like. . As the light source 40 (and the projection head 41), for example, a halogen lamp can be used.
Light from the light source 40 is transmitted to the light projecting head 41 by the light projecting optical system 42, and is projected (irradiated) to the film formation target substrate 30 as the monitor light L.

  The light projecting head 41 is formed by, for example, a half mirror, a dichroic mirror, a dichroic prism, or the like, transmits the monitor light L and emits it toward the film formation target substrate 30, and the reflected monitor light LR by the surface of the film formation target substrate 30. Is reflected and reflected in a direction different from the emission direction of the monitor light L, for example, a direction orthogonal thereto.

  In the present embodiment, the monitor light L is transmitted through the film formation target substrate 30 from the front surface side facing the film formation material supply unit 200 to the back surface side, and the film formation target. It is separated into reflected monitor light LR reflected by the surface of the substrate 30.

  Further, for example, as the light projecting head support portion 43, existing equipment can be used for the vacuum chamber 10 such as a correction plate used for correcting the film thickness distribution.

The vacuum film formation apparatus according to the present embodiment receives, for example, the reflection monitor light LR reflected by the surface side of the film formation target substrate 30 and acquired by the reflected light acquisition unit 411, and outputs the first light reception signal _SR1 . a first light receiving portion 500 to the second light receiving unit 600 for outputting a second light receiving signal S _R2 for receiving the transmitted monitor light LT transmitted to the rear surface side of the deposition target substrate 30 is provided.

For example, the first light receiving unit 500 is provided in the vacuum chamber 10, receives the reflected monitor light LR reflected by the surface of the film formation target substrate 30 and acquired by the reflected light acquiring unit 411 of the light projecting head 41. The first light receiving head 50, the first light splitting unit 51 that splits the reflected monitor light received by the first light receiving head 50, and the first light detection unit 52 that detects the light split by the first light splitting unit 51. And a first light receiving optical system 53 such as an optical fiber that transmits the reflected monitor light LR received by the first light receiving head 50 to the first beam splitting unit 51.

For example, the first light detection unit 52 has a configuration in which light receiving pixels that convert received light into electrical signals are arranged in a matrix, and a CCD sensor or the like can be used as the first light detection unit 52.
The reflection monitor light LR reflected by the surface side of the film formation target substrate 30 is received by the first light receiving head 50, transmitted to the first beam splitting unit 51 by the first light receiving optical system 53, and dispersed and split. The light is detected by the first light detection unit 52.
In the present embodiment, for example, the reflection monitor light LR reflected by the surface of the film formation target substrate 30 is split by the first beam splitting unit 51, and the split light is detected by first light detection in which light receiving pixels are arranged in a matrix. The first light receiving signal _SR1 is output by detection by the unit 52. The first light detection unit 52 can acquire a continuous spectrum of the reflected monitor light LR, that is, can detect the reflected monitor light LR with multiple wavelengths.

  For example, the light receiving head 50 is provided so as not to hinder the rotational drive of the substrate holder 31 and the holder support portions (32, 33).

  For example, the second light receiving unit 600 is provided in the vacuum chamber 10, and is received by the second light receiving head 60 that receives the transmission monitor light LT transmitted through the film formation target substrate 30 to the back surface side, and the second light receiving head 60. The second light splitting unit 61 that splits the transmitted monitor light LT, the second light detection unit 62 that detects the light split by the second light splitting unit 61, and the transmission monitor light LT received by the second light receiving head 60 The optical system includes a second light receiving optical system 63 such as an optical fiber that transmits to the second light splitting unit 61, a light receiving head support unit 64 that supports the second light receiving head 60, and the like.

For example, the second light detection unit 62 has a configuration in which light receiving pixels that convert received light into electrical signals are arranged in a matrix, and a CCD sensor or the like can be used as the second light detection unit 62.
The transmission monitor light LT transmitted through the film formation target substrate to the back surface side is received by the second light receiving head 60, transmitted to the second beam splitting unit 61 by the second light receiving optical system 63, and dispersed and split. It is detected by the second light detection unit 62.
The transmission monitor light LT transmitted through the film formation target substrate to the back surface side is split by the second beam splitting unit 61, and the split light is detected by the second light detection unit 62 in which the light receiving pixels are arranged in a matrix. 2 The light reception signal _SR2 is output. The second light detection unit 62 can acquire a continuous spectrum of the transmission monitor light, that is, can detect the transmission monitor light LT with multiple wavelengths.

  For example, the light receiving head support portion 64 that supports the light receiving head 60 is provided so as not to hinder the rotational drive of the substrate holder 31 and the holder support portions (32, 33).

FIG. 2A is a schematic diagram of a main part of the vacuum vapor deposition apparatus of FIG.
For example, a plurality of deposition target substrates 30 are held on a substrate holder 31 that has a dome shape and is rotated about the top of the dome as a center of rotation so that the film formation surface faces the film formation material supply unit. ing.
A monitor light L is projected from a light projection unit (not shown) to the film formation target substrate 30, and the reflected monitor light LR reflected by the surface of the film formation target substrate 30 is received by the first light receiving head 50. Transmission monitor light LT transmitted to the back side of the film formation target substrate 30 is received by the second light receiving head 60.

FIG. 2B is a schematic plan view of the deposition target substrate in FIG.
For example, the projected light spot SP _L of the monitor light L is arranged to be irradiated on the film-forming target substrate 30 disposed on the outer peripheral portion of the substrate holder 31. The vicinity of the region R traced by the projection spot SP _L is a non-defective product distribution region.

In this embodiment, for example, connected to a motor 34 for rotating the substrate holder 31, the trigger signal output section 35 for outputting a trigger signal S _T in synchronism with the rotation of the substrate holder 31 is provided.
In the present embodiment, for example, the signal received by the first light receiving signal _{S R1} by the first light receiving portion 500, the trigger signal _{S T} of the second light receiving portion 600 by the second light receiving signal _{S R2} and the trigger signal output section 35, is supplied A processing unit 70 is provided.

  In the present embodiment, the signal processing unit 70 is configured to receive a mode signal MD by a control system (not shown) and perform signal processing according to, for example, the first mode MD1 or the second mode MD2.

[Processing in the first mode of the signal processing unit]
For example, when the mode signal MD indicates an operation in the first mode MD1, the signal processing unit 70 includes an absorption film that is difficult to deal with film thickness control with transmission monitor light, for example, as shown in FIG. The following processing is performed for forming the ND filter 90.
That is, the signal processing section 70, in the first mode MD1, formed by performing predetermined signal processing based on the first light receiving signal S _R1 and the trigger signal S _T corresponding to the reflected monitor light LR of the first light receiving portion 500 The light reflectance (change information of the reflected monitor light LR) for each film target substrate 30 is acquired.
Further, the signal processing unit 70 acquires a light reflection spectrum for each film formation target substrate by acquiring a continuous spectrum of the reflected monitor light as described above.
In the present embodiment, feedback can be performed through a control system (not shown) during film formation so as to change the film formation conditions so as to obtain desired optical characteristics from the obtained light reflectance or light reflection spectrum. .

In the present embodiment, in the first mode MD1, the second light receiving signal S _R2 and predetermined signal processing based on the trigger signal S _T corresponding to the transmitted monitor light LT of the second light receiving unit 600 as needed To obtain the light transmittance (change information of the transmission monitor light LT) for each film formation target substrate 30.
The signal processing unit 70 generates information for estimating and monitoring the film thickness of the thin film on the film formation target substrate from the change in the reflection monitor light on the deposition surface side surface (front surface) of the film formation target substrate 30. Based on the acquired information of the light transmittance (change in the transmission monitor light LT), information for monitoring the progress of the reaction during the film formation of each film is generated.

  As described above, the vacuum film forming apparatus according to the present embodiment increases the size and cost of the optical system while supporting mass production even in the case of including an absorption film in the vacuum film forming process for manufacturing an optical thin film. It is possible to improve the yield while suppressing, and to monitor the progress of the reaction during film formation as necessary.

  FIG. 3 is a schematic cross-sectional view of an absorption ND filter manufactured by the vacuum film forming apparatus according to the present embodiment.

  The absorption ND filter 90 of FIG. 3 includes a first dielectric film 92, a first light absorption film 93, a second dielectric film 94, a second light absorption film 95, and a first dielectric film 92 on a substrate 91 such as glass or plastic. The three dielectric films 96 are configured as a laminated structure in which the films are formed in the order shown.

The first dielectric film 92 is formed of, for example, SiO ₂ and the film thickness is controlled to about 60 nm.
The first light absorption film 93 contains, for example, metal Ti and its saturated oxide TiO ₂ as main components, and other residual components such as lower oxides Ti ₂ O ₃ and TiO, and by-products such as metal compounds TiN. doing. The film thickness of the first light absorption film 93 is controlled to about 30 nm.
The second dielectric film 94 is formed, for example by SiO _2, the thickness is controlled to about 50nm.
The second light absorption film 95 contains, for example, metal Ti and its saturated oxide TiO ₂ as main components, and other residual components such as lower oxides Ti ₂ O ₃ and TiO, and by-products such as metal compounds TiN. doing. The film thickness of the second light absorption film 95 is controlled to about 25 nm.
The third dielectric film 96 is formed of, for example, SiO ₂ and the film thickness is controlled to about 80 nm.

  In the ND filter 90, the third dielectric film 96 side corresponds to the outermost surface side.

Note that the stacked configuration shown in FIG. 3 is an example, and other configurations may be used.
In the case of an optical thin film, a ceramic material that is transparent at a normal use wavelength is expressed as a dielectric film. By laminating dielectrics having a thickness (about several times the wavelength) in which the light interference effect appears, optical characteristics such as reflection amount, transmission amount, and polarization of incident light can be adjusted.
By adopting the configuration shown in FIG. 3, the ND filter is provided with an antireflection function.

In the present embodiment, for example, an ND filter having a structure as shown in FIG. 3 corresponds to change information of the reflected monitor light LR reflected on the surface side of the film formation target substrate 30 of the monitor light L in the first mode MD1. It is manufactured while estimating and monitoring the thickness of the thin film on the deposition target substrate.
Then, in the first mode, the signal processing unit 70 changes the reaction at the time of film formation from the change (change in the amount of light) of the transmitted monitor light LT transmitted through the film formation target substrate 30 of the monitor light L to the back surface side. Process to generate information to monitor progress.

FIG. 4 is a diagram showing a monitor example of the progress of the reaction during the formation of each film of the optical filter (ND filter) including the absorption layer (light absorption film) by the transmission monitor light in the present embodiment.
FIG. 5 is a diagram illustrating a monitor example of a reaction progress state when a predetermined dielectric film of an optical filter (ND filter) is formed by transmission monitor light in the present embodiment.

The monitor example based on the information in FIG. 4 shows a change in the light amount of the transmission monitor light LT after each film of the ND filter 90 in FIG. 3 is formed.
However, this is only an example, and it is possible to monitor the progress of the reaction during film formation by monitoring the change in the light amount of the transmission monitor light LT each time a film is formed.

4, layer 1 corresponds to the SiO ₂ film that is the third dielectric film 96 of FIG. 3, and layer 2 corresponds to the absorption film made of Ti or the like of the second light absorption film 95 of FIG. Corresponds to the SiO ₂ film as the second dielectric film 94 in FIG. 3, the layer 4 corresponds to the absorption film made of Ti or the like of the first light absorption film 93 in FIG. 3, and the layer 5 corresponds to the first film in FIG. This corresponds to the SiO ₂ film which is the dielectric film 92.

In the monitor based on the information of FIG. 4, in the SiO ₂ film that is the third dielectric film 96, the change in the light amount of the transmitted monitor light LT is almost constant without attenuation, and the light amount is maintained at about 95%. As shown in FIGS. 4 and 5, it is confirmed that the SiO ₂ film as the third dielectric film 96 exhibits an antireflection function and the degree of progress of the reaction during the film formation is good.

  The second light absorption film 95 made of Ti or the like exhibits a light absorption function, and the amount of the transmitted monitor light LT is greatly reduced from about 95% to about 31% according to the film thickness. It is confirmed that the second light absorption film 95 exhibits a good light absorption function and the degree of progress of the reaction during film formation is good.

In the SiO ₂ film, which is the next second dielectric film 94, the change in the light amount of the transmitted monitor light LT is almost constant without being attenuated, and the light amount is maintained at about 31%. It is confirmed that the SiO ₂ film as the second dielectric film 94 exhibits an antireflection function, and the degree of progress of the reaction during film formation is good.

  The first light absorption film 93 made of Ti or the like exhibits a light absorption function, and the amount of transmitted monitor light LT is reduced from about 31% to about 11% according to the film thickness. It is confirmed that the first light absorption film 93 exhibits a good light absorption function and the degree of progress of the reaction during film formation is good.

In the SiO ₂ film, which is the next first dielectric film 92, the change in the light amount of the transmitted monitor light LT is substantially constant without attenuation, and the light amount is maintained at about 11%. It is confirmed that the SiO ₂ film as the first dielectric film 92 exhibits an antireflection function and the degree of progress of the reaction during film formation is good.

  As described above, the vacuum film forming apparatus according to the present embodiment increases the size and cost of the optical system while supporting mass production even in the case of including an absorption film in the vacuum film forming process for manufacturing an optical thin film. While suppressing, the yield can be improved, and the progress of the reaction during film formation can be monitored.

[Processing in second mode of signal processor]
In the above-described first mode, the absorption ND filter includes an absorption film formed of a non-oxidized metal film that is not completely oxidized. Therefore, when the first layer is stacked in a change in light transmittance, Although the first peak appears, the next peak does not appear (cannot be seen) even if the thin film is laminated thereafter, so that the control is performed to monitor the optical film thickness of each film mainly using the reflection monitor light LR.
In the vacuum film forming apparatus according to the present embodiment, when producing an optical filter that does not include an absorption film, a plurality of small peaks appear in the temporal change in the light transmittance of the monitor light. The film thickness of each layer can be monitored by monitoring (monitoring) the light transmittance using the transmission monitor light LT.
In the present embodiment, this process is performed in the second mode MD2.

For example, when the mode signal MD indicates an operation in the second mode MD2, the signal processing unit 70 is an optical thin film such as an NBP filter (narrowband bandpass filter) that can handle film thickness control with transmission monitor light. As the film is formed, the following processing is performed.
That is, the signal processing section 70, when the second mode MD2, formed by performing predetermined signal processing based on the second light receiving signal S _R2 and the trigger signal S _T corresponding to the transmitted monitor light LT of the second light receiving portion 600 The light transmittance for each film target substrate 30 is acquired.
Further, the signal processing unit 70 acquires a light transmission spectrum for each film formation target substrate by acquiring a continuous spectrum of the transmission monitor light as described above.
In the present embodiment, feedback can be performed through a control system (not shown) during film formation so as to change the film formation conditions so as to obtain desired optical characteristics from the obtained light transmittance or light transmission spectrum. .

For example, in the second mode MD2, it is possible to produce an NBP filter in which 66 layers of SiO ₂ / TiO ₂ are alternately laminated on an optical glass substrate using the ion beam assisted vacuum deposition apparatus of the above embodiment. . For example, the center wavelength of the transmission band is 827 nm, and the bandwidth is 12 nm or less.
In this case, the film thickness of the thin film can be controlled with high accuracy by the direct film thickness monitoring method.

In the above description, in the first mode MD1, control is performed by monitoring using the main reflection monitor light LR and the transmission monitor light LT for confirming reaction progress, and in the second mode MD2, the transmission monitor light LT is used. An example of performing control by a monitor was explained.
However, the vacuum film forming apparatus according to the present embodiment can have various modes such as using only the reflected monitor light LR and using the reflected monitor light LR in addition to the main transmitted monitor light LT according to the application. is there.

  Next, the signal processing of this embodiment including a trigger signal will be described.

FIG. 6 is a diagram for explaining an example of signal processing according to the vacuum vapor deposition apparatus of the present embodiment.
Projected light spot SP _L of the monitor light L, by the substrate holder 31 is rotated, a plurality of deposition target substrate _{(30 1} disposed on an outer peripheral portion of the substrate holder 31, 30 _2, 30 3 ... 30 _n ) Pass over.
By receiving the monitor light L reflected or transmitted through the moving deposition target substrates (30 ₁ , 30 ₂ , 30 ₃ ... 30 _n ), each deposition target substrate (30 ₁ , 30 ₂ , 30 _3. · · 30 _n) light reflectance or light transmittance are acquired intermittently reflect received light signal S _R.
Here, the trigger signal S _T in synchronism with the rotation of the substrate holder 31, by specifying the position of the substrate holder 31 rotates, the light reflectance or light transmittance of the film formation target substrate 30 is intermittently reflect In addition, it is possible to specify which part of the received light signal SR _(1,2) has the light reflectance or light transmittance with respect to which film formation target substrate. The trigger signal _ST is output once per rotation period of the substrate holder 31 or output many times.
By receiving the signal S _R throat portion of said to identify whether the light reflectance or light transmittance to any of the film-forming target substrate, the light receiving signals S ₁ with respect to the light receiving signal S _R, the deposition target substrate 30 _1, receiving signal _{S 2} for the deposition target substrate 30 _2, the light receiving signal _S 3 for the deposition target substrate 30 _3, it is possible to obtain a light reception signal _{S n} for ... deposition target substrate 30 _n.

  For example, when the starting radius of the center of the deposition target substrate located on the outer periphery of the substrate holder is 450 mm, the diameter of the deposition target substrate is 30 mm, and the rotation speed of the substrate holder is 30 rpm, the monitor light is handled as a point light source. The monitoring time per rotation of the substrate holder per sheet deposition target substrate is 21 ms. Since the spot diameter of the monitor light has a certain size, the monitoring time is further shortened. In order to ensure high film thickness controllability within this limited time, high light detection sensitivity is required.

  For example, by using a CCD sensor or the like as the light detection units 52 and 62, the amount of information obtained by obtaining information on light reflectance or light transmittance at multiple wavelengths can be increased. The accuracy of the transmittance can be increased and the S / N ratio can be improved.

  Next, the structural example of the principal part of the vacuum evaporation apparatus of FIG. 1 is further demonstrated.

FIGS. 7A and 7B are schematic views of the main part of the vacuum vapor deposition apparatus of FIG.
For example, as described above, the monitor light L is projected from the light projecting head 41 constituting the light projecting unit onto the film formation target substrate 30 held on the outer periphery of the substrate holder 31.
The reflection monitor light LR reflected by the surface of the film formation target substrate 30 is received by the first light receiving head 50 constituting the light reception optical system, and the transmission monitor light LT transmitted through the film formation target substrate 30 to the back surface side is received by the light reception optical system. The light is received by the second light receiving head 60 constituting the.
The substrate holder 31 shown in FIG. 7A and the substrate holder 31 shown in FIG. 7B have different diameters and different numbers and sizes of deposition target substrates that can be held.
In the above configuration, for example, the position of the second light receiving head 60 of the light receiving optical system is variably provided.

For example, the light receiving head support portion 64 is provided so as to be expandable / contractable, bendable, or expandable / contractable, and is configured so that the position of the light receiving head of the light receiving optical system can be changed.
For example, when the relatively large substrate holder 31 shown in FIG. 7A is used, the second light receiving head 60 receives the transmission monitor light LT transmitted through the film formation target substrate 30 held on the outer periphery of the substrate holder 31. The light receiving head support portion 64 is extended so as to reach the position where it moves.
On the other hand, for example, when the relatively small substrate holder 31 shown in FIG. 7B is used, the light receiving head 60 receives the monitor light L transmitted through the film formation target substrate 30 held on the outer periphery of the substrate holder 31. The light receiving head support 64 is contracted or bent so as to reach the position.

For example, as shown in FIG. 1, a heater is provided in the vicinity of the substrate holder and the light receiving optical system. Heating with the heater 80 can prevent unnecessary vapor deposition material from being deposited on the inner wall surface of the vacuum chamber 10 near the substrate holder.
For the heater 80, a resistance heating member made of, for example, a halogen lamp or nickel chrome can be used.
In this case, for example, by using a light receiving optical system having heat resistance against heating by the heater, damage due to the heater of the light receiving optical system can be suppressed.

[Vacuum deposition method]
Next, an ion beam assisted vacuum deposition method will be described as a vacuum film formation method according to the present embodiment. The vacuum film forming method according to the present embodiment is performed using the vacuum film forming apparatus of the present embodiment described above.
FIG. 8 is a flowchart for explaining a method of producing an optical thin film such as an absorption ND filter in the vacuum film forming apparatus of this embodiment.

First, for example, a plurality of sheets are formed on the substrate holder 31 of the vacuum chamber 10 in which the film forming material supply unit 200 and the substrate holder having a dome-like shape and having the top of the dome rotated about the rotation center are provided. The film target substrate 30 is held (step ST1).
Here, the film formation target substrate 30 is held such that the film formation surface (front surface side) faces the film formation material supply unit 200 side.
For example, the substrate holder 31 holding the film formation target substrate 30 is rotated about the top of the dome as the rotation center (step ST2).

Next, a film forming material is supplied from the film forming material supply unit 200 to form a film of the film forming material on the film formation target substrate 30 (step ST3).
Next, for example, the monitor light L is projected onto the film formation target substrate 30 held on the outer peripheral portion of the substrate holder 31 (step ST4).
Next, the signal processing unit 70 determines whether or not the operation mode is the first mode MD1 (step ST5).
In the case of the first mode MD1, the signal processing unit 70 transmits the first light reception signal S _R1 obtained by receiving the reflection monitor light LR on the surface of the film formation target substrate 30 and the film formation target substrate 30 to the back surface side. The second light reception signal _SR2 obtained by receiving the transmitted transmission monitor light LT is acquired (step ST6).
The signal processing unit 70 obtains the trigger signal _{S T} in synchronism with the rotation of the substrate holder 31 (step ST7).

In the first mode MD1, the signal processing section 70, the first light receiving signal S _R1 and the trigger signal S film-forming target substrate by performing a predetermined signal processing based on the _T corresponding to the reflected monitor light LR of the first light receiving portion 500 The light reflectance (change information of the reflected monitor light LR) for every 30 is acquired (step ST8).
Further, the signal processing unit 70 acquires a light reflection spectrum for each film formation target substrate by acquiring a continuous spectrum of the reflected monitor light as described above.
Based on this, during the film formation, for example, in the control system, the film formation conditions are changed so that desired optical characteristics can be obtained from the obtained light reflectance (change information of the reflected monitor light LR) or the light reflection spectrum. Is fed back through.

The signal processing unit 70, in the first mode MD1, by performing predetermined signal processing based on the second light receiving signal S _R2 and the trigger signal S _T corresponding to the transmitted monitor light LT of the second light receiving portion 600 deposited The light transmittance (change information of transmission monitor light LT) for each target substrate 30 is acquired (step ST9).
The signal processing unit 70 generates information for estimating and monitoring the film thickness of the thin film on the film formation target substrate from the change in the reflection monitor light LR on the vapor deposition surface side surface (front surface) of the film formation target substrate 30. At the same time, based on the acquired information on the light transmittance (change in the transmission monitor light LT), processing is performed so as to generate information for monitoring the progress of the reaction during film formation (step ST10).

  As described above, the vacuum film forming apparatus according to the present embodiment has a large optical system in the first mode MD1 while accommodating an absorption film in a vacuum film forming process for manufacturing an optical thin film, even if it includes an absorption film. The yield can be improved while suppressing the increase in cost and cost, and the progress of the reaction during film formation can be monitored.

On the other hand, when it is determined in step ST5 that the mode is not the first mode MD1 but the second mode MD2, the signal processing unit 70 is obtained, for example, by receiving the transmission monitor light LT transmitted through the film formation target substrate to the back side. The second light receiving signal _SR2 is acquired (step ST11).
Then, the signal processing unit 70 obtains the trigger signal _{S T} in synchronism with the rotation of the substrate holder 31 (step ST12).
Then, for example, by the second light receiving signal S _R2 and the trigger signal S _T and the signal processing to obtain the light transmittance of the film-forming target each substrate.
The signal processing unit 70, in the second mode MD2, based on the second light receiving signal S _R2 and the trigger signal S _T corresponding to the transmitted monitor light LT of the second light receiving portion 600, the film-forming target by performing predetermined signal processing The light transmittance for each substrate 30 is acquired (step ST13).
The signal processing unit 70 generates information for estimating and monitoring the film thickness of the thin film on the film formation target substrate from the change in the light transmittance of the transmission monitor light LT transmitted to the back surface side of the film formation target substrate 30. (ST14).
Further, the signal processing unit 70 acquires a light transmission spectrum for each film formation target substrate by acquiring a continuous spectrum of the transmission monitor light.
Based on this, feedback is made, for example, through a control system during film formation so that the film formation conditions are changed so as to obtain desired optical characteristics from the obtained light transmittance or light transmission spectrum.

  In the second mode MD2, the vacuum film formation apparatus of the present embodiment holds a plurality of film formation target substrates on the substrate holder, and projects monitor light onto the film formation target substrates held on the outer periphery of the substrate holder. In this process, the light transmittance of each film formation target substrate is acquired by receiving the monitor light that has passed through this, and in the vacuum film formation process for manufacturing the optical filter, the yield can be improved while accommodating mass production. it can.

In the present embodiment, for example, as the light receiving unit, a light receiving optical system that receives and transmits monitor light transmitted through the film formation target substrate, a spectroscopic unit that splits the monitor light, and light that has been split by the spectroscopic unit. It is configured to have a light detection unit such as a CCD sensor for detection, and monitor light can be detected with multiple wavelengths.
For example, by increasing the light detection sensitivity, the accuracy of the signal can be improved and the S / N ratio can be improved. Further, the amount of information obtained by obtaining information on light transmittance at multiple wavelengths using a CCD sensor or the like can be increased. It is possible to improve the accuracy of light transmittance and improve the S / N ratio.

For example, a light receiving optical system provided with a variable position can be used.
The position of the light receiving head of the light receiving optical system can be changed by using the light receiving head support portion 64 provided to be extendable, bendable, or extendable and bendable, even when using a substrate holder having a different curved shape, The light transmittance or spectral accuracy of the film formation target substrate held on the outer periphery of the substrate holder can be increased.

FIGS. 9A and 9B are schematic views of main parts of a modification of the vacuum vapor deposition apparatus of FIG.
For example, the monitor light L is projected from the light projecting head 41 constituting the light projecting unit on the film formation target substrate 30 held on the outer periphery of the planar disk-shaped substrate holder 36.
The reflection monitor light LR reflected by the surface of the film formation target substrate 30 is received by the first light receiving head 50 constituting the light reception optical system, and the transmission monitor light LT transmitted through the film formation target substrate 30 to the back surface side is received by the light reception optical system. The light is received by the second light receiving head 60 constituting the.
Both the substrate holder 36 shown in FIG. 9A and the substrate holder 36 shown in FIG. 9B have a flat disk shape, but have different diameters and different numbers and sizes of deposition target substrates that can be held. Yes.
In the above configuration, for example, the position of the second light receiving head 60 of the light receiving optical system is variably provided.

For example, the light receiving head support portion 64 is provided so as to be expandable / contractable, bendable, or expandable / contractable, and is configured so that the position of the light receiving head of the light receiving optical system can be changed.
For example, when the relatively large substrate holder 36 shown in FIG. 9A is used, the transmitted monitor light is transmitted through the film formation target substrate 30 held on the outer peripheral portion of the substrate holder 36 by the second light receiving head 60 to the back surface side. The light receiving head support 64 is extended so as to reach the position for receiving LT.
On the other hand, for example, when the relatively small substrate holder 36 shown in FIG. 9B is used, the second light receiving head 60 transmits the film formation target substrate 30 held on the outer peripheral portion of the substrate holder 36 to the back side. The light receiving head support portion 64 is contracted or bent so as to reach a position for receiving the monitor light LT.
When using a light receiving head support 64 provided to be extendable, bendable, or extendable and bendable, the position of the light receiving head of the light receiving optical system can be changed, and a substrate holder having a planar shape and a different diameter is used. However, the light transmittance or spectral accuracy of the film formation target substrate held on the outer peripheral portion of the substrate holder can be increased.

For example, the light projecting unit projects the monitor light so as to enter the film forming surface of the film formation target substrate substantially perpendicularly.
Thereby, the light transmittance or spectrum accuracy of the deposition target substrate can be increased.

For example, heating with a heater provided in the vicinity of the substrate holder and the light receiving optical system can prevent unnecessary vapor deposition material from being deposited on the inner wall surface of the vacuum chamber 10 in the vicinity of the substrate holder.
In this case, for example, by using a light receiving optical system having heat resistance against heating by the heater, damage due to the heater of the light receiving optical system can be suppressed.

As described above, according to the present embodiment, the following configuration is provided.
That is, according to the vacuum film forming apparatus of the present embodiment, the signal processing unit 70 responds to the reflection monitor light LR of the first light receiving unit 500 in the first mode MD1 when producing an ND filter including an absorption film. first light receiving signal S _R1 and the trigger signal S given optical reflectance of the film-forming target substrate 30 each performs signal processing based on _T (change information of the reflected monitor light LR) to obtain a.
Further, the signal processing unit 70 acquires a light reflection spectrum for each film formation target substrate by acquiring a continuous spectrum of the reflected monitor light as described above.
In the present embodiment, feedback can be performed through a control system (not shown) during film formation so as to change the film formation conditions so as to obtain desired optical characteristics from the obtained light reflectance or light reflection spectrum. .

In the present embodiment, in the first mode MD1, formed by performing predetermined signal processing based on the second light receiving signal S _R2 and the trigger signal S _T corresponding to the transmitted monitor light LT of the second light receiving portion 600 The light transmittance (change information of the transmission monitor light LT) for each film target substrate 30 is acquired.
The signal processing unit 70 generates information for estimating and monitoring the film thickness of the thin film on the film formation target substrate from the change in the reflection monitor light on the deposition surface side surface (front surface) of the film formation target substrate 30. Based on the acquired information on the light transmittance (change in the transmission monitor light LT), processing is performed so as to generate information for monitoring the progress of the reaction during film formation.

  As described above, the vacuum film forming apparatus according to the present embodiment increases the size and cost of the optical system while supporting mass production even in the case of including an absorption film in the vacuum film forming process for manufacturing an optical thin film. There is an advantage that the yield can be improved while suppressing, and the progress of the reaction during film formation can be monitored.

The signal processing unit 70, the case of producing an optical thin film containing no absorption film, in the second mode MD2, the second light receiving signal S _R2 and the trigger signal S _T corresponding to the transmitted monitor light LT of the second light receiving portion 600 Based on the above, predetermined signal processing is performed to obtain the light transmittance for each film formation target substrate 30.
Further, the signal processing unit 70 acquires a light transmission spectrum for each film formation target substrate by acquiring a continuous spectrum of the transmission monitor light as described above.
In the present embodiment, feedback can be performed through a control system (not shown) during film formation so as to change the film formation conditions so as to obtain desired optical characteristics from the obtained light transmittance or light transmission spectrum. .
As described above, in the second mode MD2, the transmission monitor light transmitted through the film formation target substrate to the back side is received and the light transmittance of each film formation target substrate is obtained, and the vacuum for manufacturing the optical filter is obtained. In the film formation process, the yield can be improved while accommodating mass production.

The present invention is not limited to the above description.
For example, the present invention is not limited to the ion beam assisted vacuum deposition apparatus and method, and can be applied to other vacuum film forming apparatuses and methods. Further, in addition to vacuum film formation, the present invention can be applied to other thin film forming apparatuses and methods such as film formation by sputtering or film formation by CVD (chemical vapor deposition).
The trigger signal may be output once per cycle of the substrate holder rotation or multiple times.
Further, the rotation position of the rotation axis of the substrate holder is detected using an encoder, and the obtained position information of the substrate holder is input to the signal processing unit to obtain the light reflectance or light transmittance for each film formation target substrate. A configuration is also possible.
In the above embodiment, the light projecting unit, the light receiving unit, the trigger signal output unit, and the signal processing unit are formed on the film formation target substrate by obtaining the light reflectance or light transmittance of each film formation target substrate. And an apparatus for monitoring the optical film thickness of the thin film. As an optical thin film monitoring device, the optical film thickness of the thin film formed on the film formation target substrate can be monitored by being detached from the vacuum film forming device and attached to another thin film forming device.

  In the above-described embodiments, the monitor (monitoring) control function during film formation has been described. However, the apparatus according to the present invention is not limited to a monitor control function such as a film thickness during film formation, but also a chemical by reaction gas. It also has a reaction control function.

FIG. 10 is a flowchart for explaining a monitor control function of a chemical reaction when an optical thin film is produced in the present embodiment.
For example, while the film formation process is stopped (step ST21), a reactive gas such as oxygen (O ₂ ) is flowed (step ST22) to change the light transmittance of the substrate (change in the transmission monitor light LT). Information) is acquired (step ST23).
Specifically, in the apparatus of FIG. 1, the second light receiving signal S _R2 and the trigger signal deposition target substrate 30 by performing predetermined signal processing based on S _T corresponding to the transmitted monitor light LT of the second light receiving portion 600 Get the light transmittance for each.
The signal processing unit generates information for monitoring the progress of the reaction during the chemical reaction processing of the film based on the acquired information on the light transmittance (change in the transmission monitor light LT).
For example, when the light transmittance of the substrate changes due to oxidation or reaches a certain light transmittance (step ST24), the oxidation process is terminated (step ST25), and the process proceeds to the next process (step).
The present invention may be configured to have such a monitor control function of a chemical reaction by a reaction gas.

  In addition, various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Vacuum chamber, 11 ... Exhaust pipe, 12 ... Vacuum pump, 200 ... Film formation material supply part, 20 ... 1st vacuum evaporation source, 21 ... 1st vapor deposition material, 22 ... second vacuum deposition source, 23 ... second deposition material, 24 ... ion source, 300 ... substrate holder, 30,30 ₁ ~30 _n ... ·· deposition target substrate, 31 ... Substrate holder, 32, 33 ... Holder support part, 34 ... Motor, 35 ... Trigger signal output part, 36 ... Substrate holder, 400 ... Projection part, 40 ... Light source, 41... Projection head, 411... Reflected light acquisition unit, 42... Projection optical system, 43 ... Projection head support unit, 500. First light receiving head, 51... First beam splitting unit, 52... First light detection unit, 53. 00 ... second light receiving unit, 60 ... second light receiving head, 61 ... second light splitting unit, 62 ... second light detection unit, 63 ... second light receiving optical system, 64 ... light receiving Head support part 70 ... Signal processing part 110 ... Vacuum chamber 120 ... First vacuum deposition source 121 ... First deposition material 122 ... Second vacuum deposition source 123 ..Second vapor deposition material, 130 ... Substrate to be deposited, 131 ... Substrate holder, 132 ... Monitor substrate, 141 ... Light emitter, 150 ... Light receiver, 151 ... Throw receiving unit, L · · · monitor light, LR · · · reflected monitor light, LT · · · transmission monitor _light, S 1 _{to S} n · · · receiving _{signal, S R1} · · · first light receiving _{signal, S R2} · ... the second light receiving _{signal, S} T ··· trigger signal, _SP L ··· projected light spot.

Claims (6)

A deposition chamber;
A film forming material supply unit disposed in the film forming chamber;
Arranged in the film forming chamber, holds a plurality of film forming target substrates so that the film forming surface faces the film forming material supply unit side, and has a dome shape or a planar disk shape, A substrate holder that is rotated about the center of the top or plane disc, and
A light projecting unit that projects monitor light onto the film formation target substrate held on the outer periphery of the substrate holder;
Of the monitor light, a first light receiving unit that receives reflected monitor light reflected on a surface side that is a film forming surface of the film formation target substrate and outputs a first light reception signal;
A second light receiving unit that receives the transmitted monitor light transmitted to the back side of the film formation target substrate and outputs a second light reception signal among the monitor light;
A trigger signal output unit for outputting a trigger signal synchronized with the rotation of the substrate holder;
A signal processing unit that performs predetermined signal processing based on the first light reception signal and the trigger signal to obtain change information of the reflection monitor light for each film formation target substrate;
Have
The signal processing unit
A function of performing predetermined signal processing based on the second received light signal and the trigger signal to obtain change information of the transmission monitor light for each film formation target substrate;
Process to generate information for estimating and monitoring the thickness of the thin film on the film formation target substrate based on the change information of the reflection monitor light on the surface side of the film formation target substrate,
A thin film forming apparatus that performs processing so as to generate information for monitoring a progress state of a reaction during film formation based on change information of the transmission monitor light transmitted to the rear surface side of the film formation target substrate. In the state where the film formation process is stopped and the reactive gas is flown during the film formation process stop,
The signal processing unit
The thin film forming apparatus according to claim 1, wherein processing is performed so as to generate information for monitoring a progress state of a chemical reaction of the film based on change information of the transmission monitor light transmitted to the rear surface side of the film formation target substrate. A deposition chamber;
A film forming material supply unit disposed in the film forming chamber;
Arranged in the film forming chamber, holds a plurality of film forming target substrates so that the film forming surface faces the film forming material supply unit side, and has a dome shape or a planar disk shape, A substrate holder that is rotated about the center of the top or plane disc, and
A light projecting unit that projects monitor light onto the film formation target substrate held on the outer periphery of the substrate holder;
Of the monitor light, a first light receiving unit that receives reflected monitor light reflected on a surface side that is a film forming surface of the film formation target substrate and outputs a first light reception signal;
A trigger signal output unit for outputting a trigger signal synchronized with the rotation of the substrate holder;
A signal processing unit that performs predetermined signal processing based on the first light reception signal and the trigger signal to obtain change information of the reflection monitor light for each film formation target substrate;
Have
In the state where the film formation process is stopped and the reactive gas is flown during the film formation process stop,
The signal processing unit
Thin film forming device for processing to generate information to monitor the progress of chemical reactions of the film based on the transmission of change information transparently monitor light on the back side of the film-forming target substrate. The substrate holder of the film forming chamber, in which a film forming material supply unit and a substrate holder having a dome-like shape or a flat disk shape and being rotated around the top of the dome or the center of the flat disk are arranged. Holding a plurality of film formation target substrates so that the film formation surface faces the film formation material supply unit side, and rotating the top of the dome or the center of the flat disk as a rotation center;
Supplying a film forming material from the film forming material supply unit to form a film of the film forming material on the film formation target substrate;
Projecting monitor light onto the film formation target substrate held on the outer periphery of the substrate holder;
Receiving the reflected monitor light reflected on the surface side which is the film forming surface of the film formation target substrate among the monitor lights, and obtaining a first received light signal;
Receiving the transmitted monitor light transmitted to the back side of the film formation target substrate among the monitor light and obtaining a second received light signal;
Obtaining a trigger signal synchronized with the rotation of the substrate holder;
Performing predetermined signal processing based on the first light reception signal and the trigger signal to obtain change information of the reflection monitor light for each film formation target substrate; based on the second light reception signal and the trigger signal Performing predetermined signal processing to obtain change information of the transmission monitor light for each of the deposition target substrates;
Have
Process to generate information for estimating and monitoring the thickness of the thin film on the film formation target substrate based on the change information of the reflection monitor light on the surface side of the film formation target substrate,
A method for forming a thin film, wherein processing is performed so as to generate information for monitoring the progress of a reaction during film formation on the basis of change information of the transmission monitor light transmitted to the rear surface side of the film formation target substrate. In the state where the film formation process is stopped and the reaction gas is flown during the film formation process stop,
The thin film formation method according to claim 4, wherein processing is performed so as to generate information for monitoring a progress state of a chemical reaction of the film based on change information of the transmission monitor light transmitted to the rear surface side of the deposition target substrate. The substrate holder of the film forming chamber, in which a film forming material supply unit and a substrate holder having a dome-like shape or a flat disk shape and being rotated around the top of the dome or the center of the flat disk are arranged. Holding a plurality of film formation target substrates so that the film formation surface faces the film formation material supply unit side, and rotating the top of the dome or the center of the flat disk as a rotation center;
Supplying a film forming material from the film forming material supply unit to form a film of the film forming material on the film formation target substrate;
Projecting monitor light onto the film formation target substrate held on the outer periphery of the substrate holder;
Receiving the reflected monitor light reflected on the surface side which is the film forming surface of the film formation target substrate among the monitor lights, and obtaining a first received light signal;
Obtaining a trigger signal synchronized with the rotation of the substrate holder;
Performing a predetermined signal processing based on the first light reception signal and the trigger signal to obtain change information of the reflection monitor light for each film formation target substrate, and
In the state where the film formation process is stopped and the reaction gas is flown during the film formation process stop,
Thin film formation method of processing to generate information to monitor the progress of chemical reactions of the film based on the transmission of change information transparently monitor light on the back side of the film-forming target substrate.

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