JP2011060891A - Method of controlling composition of multi-source deposit thin film, and manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust a composition ratio of two or more materials at high precision to form a thin film such as CIGS film. <P>SOLUTION: According to a method of controlling the composition of a multi-source deposit thin film, a first material (Se) supplied in a chamber 11 is kept in a heated state in a film forming process. In the same film forming process, the composition ratio of two or more materials (Ga, In) supplied in the chamber 11 is detected based on a change in an oscillation frequency from a deposit on a vibrator 25 placed in the chamber 11 to control the composition ratio. In a different film forming process, the composition ratio of two or more materials (Ga, In, Cu) supplied in the chamber 11 in multiple steps is controlled by detecting the film thickness of a deposit on a measuring board 33 placed in the chamber 11 through light interference with the thin film. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a composition control method and a manufacturing apparatus for a multi-source vapor deposition thin film, and more particularly to a composition control method and a production apparatus for a multi-source vapor deposition thin film suitable for forming a CIGS film functioning as a light absorption layer in a solar cell.

The solar cell has a light absorption film.
The light absorption film absorbs sunlight and generates electric charges due to the photovoltaic effect.
The solar cell extracts this charge from the light absorption film and outputs it as electric power.
A silicon-based material or a non-silicon-based material is used for the light absorption film of the solar cell.
Examples of the silicon-based material include single crystal silicon, polycrystalline silicon, and amorphous silicon.
Non-silicon materials include, for example, GaAs, CIS (CuInSe ₂ ), CIGS (Cu (In, Ga) Se ₂ ), and organic materials.
The CIGS film is disclosed in Patent Document 1.

JP-A-8-222750

The CIGS film is a layer containing four elements of copper (Cu: copper), indium (In), gallium (Ga), and selenium (Se).
In the CIGS film, the light absorption rate (power generation efficiency) can be improved by adjusting the composition ratio of copper, indium, gallium, and selenium.
In the CIGS film, the band gap (Eg) of the CIGS film can be adjusted by the composition ratio.
Therefore, in manufacturing the CIGS film, it is necessary to optimize the composition ratio of the CIGS film.

  As described above, there is a demand for a method and an apparatus for forming a thin film by adjusting the composition ratio of two or more substances with high accuracy in a thin film made of two or more substances such as a CIGS film.

According to a first aspect of the present invention, there is provided a method for controlling a composition of a multi-source vapor deposition thin film by supplying a first substance and at least three substances to a substrate housed in a chamber, thereby forming a thin film of at least four substances on the substrate. This is a method for controlling the composition of a multi-source deposited thin film to be deposited.
In the composition control method, the first substance is supplied into the chamber, and the chamber is heated to a temperature at which the first substance does not adhere to the substrate. The composition ratio of two or more substances supplied into the chamber in the same film forming step is controlled by detecting the change in the oscillation frequency due to the deposit of the vibrator disposed in the chamber. The composition ratio of two or more substances, which are supplied into the chamber in multiple stages in different film forming steps among the at least three component substances, is determined as a deposit film on the measuring plate disposed in the chamber. The thickness is controlled by detecting by thin film interference of light.

  Preferably, the first material may be a material that does not saturate in the chamber at the heated temperature.

  Suitably, the first material may be selenium, sulfur, arsenic, or phosphorus.

  Preferably, the first material is selenium, the at least three materials are indium, gallium, and copper, and the thin film deposited on the substrate is a CIGS film that generates power by absorbing sunlight. May be.

An apparatus for producing a multi-source vapor deposition thin film according to a first aspect of the present invention accommodates a substrate on which a thin film containing at least four component substances including a first substance, a second substance, a third substance, and a fourth substance is formed. A first supply unit that supplies the first material to the chamber, a second supply unit that supplies the second material to the chamber, and the chamber in the same film formation process as the second material. A third supply unit configured to supply a third substance; a fourth supply unit configured to supply the fourth substance to the chamber in a film forming process different from the second substance and the third substance; and disposed in the chamber. An attached amount detection unit that detects the amount of attached matter that adheres to the vibrator based on a change in the oscillation frequency of the vibrator due to attached matter attached to the vibrator; Has a measuring plate disposed in the chamber. Has a thickness detector for detecting a thickness of the deposits adhering to the measurement plate by a thin film interference of light, and a heater for heating the chamber.
The manufacturing apparatus supplies the first substance into the chamber, and heats the chamber to a temperature at which the first substance does not adhere to the substrate by the heater. The second substance and the third substance Are sequentially supplied into the chamber, the composition ratio of the second substance and the third substance is controlled based on the adhesion amount detected by the adhesion amount detection unit.
Further, the manufacturing apparatus supplies the first substance into the chamber, and heats the chamber to a temperature at which the first substance does not adhere to the substrate by the heater, and the second substance and the third substance. On the basis of the film thickness detected by the film thickness detection unit when supplied into the chamber and the film thickness detected by the film thickness detection unit when supplying the fourth substance into the chamber. The composition ratio of the fourth substance to the second substance and the third substance is controlled.

Preferably, the manufacturing apparatus includes a control unit that controls the first supply unit, the second supply unit, the third supply unit, the fourth supply unit, and the heater, and executes the following control. Also good.
That is, the control unit heats the chamber to a heating temperature at which the first substance does not adhere to the substrate by the heater while the first substance is supplied from the first supply unit into the chamber.
In addition, the control unit supplies the second substance from the second supply unit at a temperature equal to or higher than the heating temperature, and causes the adhesion amount detection unit to detect the adhesion amount of the deposit based on the second substance.
In addition, the control unit supplies the third substance from the third supply unit at a temperature equal to or higher than the heating temperature, and causes the adhesion amount detection unit to detect the adhesion amount of the deposit based on the third substance.
Further, the control unit is configured to determine the second substance and the adhesion based on the adhesion amount of the deposit based on the second substance detected by the adhesion amount detection unit and the adhesion amount of the deposit based on the third substance. The supply rate of the second substance and the supply rate of the third substance are changed so that the third substance has a predetermined composition ratio, and the second substance and the third substance are simultaneously changed by the changed supply rate. Supply a thin film on the substrate.

Suitably, the said control part may perform the following control.
That is, the control unit heats the chamber to a heating temperature at which the first material does not adhere to the substrate with the heater while the first material is supplied from the first supply unit into the chamber.
The controller may simultaneously supply the second substance and the third substance from the second supply part and the third supply part at a temperature equal to or higher than the heating temperature, so that the second substance and the second substance are supplied to the substrate. A film of three substances is deposited.
In addition, the control unit supplies the fourth substance from the fourth supply unit at a temperature equal to or higher than the heating temperature, and deposits a film of the fourth substance on the substrate.
In addition, the control unit is configured to set the film thickness of the deposit detected by the film thickness detection unit and the film of the fourth material to the substrate during a period in which the film of the second material and the third material is deposited on the substrate. The composition ratio of the fourth substance to the second substance and the third substance is controlled based on the film thickness of the deposit detected by the film thickness detector during the deposition period.

  Preferably, the first material is selenium, the second material is indium, the third material is gallium, and the fourth material is copper, and is deposited on the substrate. The thin film may be a CIGS film that generates power by absorbing sunlight.

  In the present invention, a thin film made of two or more substances such as a CIGS film can be formed by adjusting the composition ratio of the two or more substances with high accuracy.

FIG. 1 is an overall view of a thin film forming apparatus according to an embodiment of the present invention. FIG. 2 is a schematic partial cross-sectional view of an example of a solar cell panel. FIG. 3 is a schematic configuration diagram of an example of the optical film thickness meter of FIG. FIG. 4 is an explanatory diagram of the film thickness measurement principle of the optical film thickness meter of FIG. FIG. 5 is a schematic configuration diagram of an example of the quartz film thickness meter of FIG. FIG. 6 is an explanatory diagram of the film thickness measurement principle of the quartz film thickness meter of FIG. FIG. 7 shows a computer apparatus as an example of the control unit shown in FIG. FIG. 8 is a comparison diagram of output characteristics of the optical film thickness meter and the crystal film thickness meter of FIG. FIG. 9 is an overall flowchart of an example of a thin film manufacturing process by the thin film forming apparatus of FIG. FIG. 10 is a time chart of the entire thin film manufacturing process by the three-stage method of FIG. FIG. 11 is a time chart in which the period A in FIG. 10 is enlarged.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall view of a thin film forming apparatus 1 according to an embodiment of the present invention.
The thin film forming apparatus 1 in FIG. 1 forms a light absorption layer 103 made of a CIGS film on a substrate 101 of a solar cell panel 100.

FIG. 2 is a schematic partial cross-sectional view of an example of the solar cell panel 100 having the light absorption layer 103 made of a CIGS film.
In the solar cell panel 100 of FIG. 2, a back electrode 102, a light absorption layer 103 using a CIGS film, a first buffer layer 104, a second buffer layer 105, a transparent electrode 106, and a reflection protective film 107 are sequentially formed on a substrate 101. It has a laminated substrate structure.
Further, extraction electrodes 108 and 109 are laminated on the back electrode 102 and the transparent electrode 106.
Note that some solar cell panels 100 do not have the first buffer layer 104.

  For the substrate 101, soda lime glass or the like is used. The substrate 101 may be hard or soft.

For the back electrode 102, molybdenum (Mo) or the like is used.
Molybdenum is formed on one surface of soda lime glass by sputtering, for example.
The back electrode 102 may be formed to a thickness of about 0.5 to 2.0 micrometers, for example.

The light absorption layer 103 made of a CIGS film absorbs sunlight and generates electric charges due to a photoelectric conversion effect. The light absorption layer 103 includes a CIS film in addition to the CIGS film.
The CIGS film is a kind of chalcopyrite type compound.
What is necessary is just to form the light absorption layer 103 in the thickness of 0.5-5.0 micrometers, for example.
The light absorption layer 103 by the CIGS film contains four elements of Cu, In, Ga, and Se.
CIGS _{film, Cu (In 1-x,} Ga x) is denoted as Se _2.
The CIGS film has a composition in which a part of indium (In) in the CIS film is replaced with gallium (Ga).

In the CIGS film, it is important to optimize the composition ratio of copper (kappa), indium, gallium, and selenium in order to improve the light absorption rate (power generation efficiency) and optimize the energy gap Eg.
In addition, since the CIGS film can be made thinner than the conventional light absorption film, it is important to form the CIGS film with a uniform thickness in order to take advantage of the characteristics.
The CIGS film is generally formed to a thickness of 2 to 4 micrometers.

CIGS film manufacturing methods include a selenization method, a four-element co-evaporation method, and a three-step method.
In these methods, a CIGS film is formed on the substrate 101 (hereinafter simply referred to as the substrate 101) on which the back electrode 102 is formed.
In the selenization method, a CIG (Cu (In, Ga)) film serving as a precursor is formed on the substrate 101 by a sputtering method or the like. In the selenization method, the CIG film is heat-treated in a hydrogen selenide (H ₂ Se) atmosphere. Thereby, a CIGS film is formed.
In the four element simultaneous vapor deposition method, the substrate 101 is accommodated in the vacuum chamber 11. In the four-element simultaneous vapor deposition method, four elements of Cu, In, Ga and Se are vapor-deposited simultaneously from different vapor deposition sources in the vacuum chamber 11. Thereby, a CIGS film is formed.
In the three-stage method, the substrate 101 is accommodated in the vacuum chamber 11. In the three-stage method, first, In, Ga, and Se are deposited. Next, Cu and Se are vapor-deposited. Next, In, Ga, and Se are deposited. As a result, a CIGS film having copper, indium, gallium and selenium as composition components is formed.
Hydrogen selenide, which is a toxic gas, is not used in multi-source deposition methods such as the four-element simultaneous deposition method and the three-stage method.

For the first buffer layer 104, cadmium sulfide (CdS) or the like is used.
The CdS layer is formed on the light absorption layer 103 by a chemical precipitation method such as a CBD method.
The first buffer layer 104 may be formed to a thickness of about several tens of nanometers, for example.

For the second buffer layer 105, zinc oxide (ZnO) or the like is used.
The ZnO layer is formed on the CdS layer by an evaporation method or the like.
The second buffer layer 105 may be formed to a thickness of about several tens of nanometers to 0.5 micrometers, for example.

As the transparent electrode 106, AZO obtained by adding alumina (Al ₂ O ₃ ) to zinc oxide (ZnO), indium tin oxide (ITO), or the like is used.
The transparent electrode 106 is formed on the first buffer layer 104 by sputtering, CVD, or the like.
The transparent electrode 106 may be formed to a thickness of about 0.1 to 2.0 micrometers, for example.

For the extraction electrodes 108 and 109, nickel (Ni), aluminum (Al), or the like is used.
The extraction electrodes 108 and 109 are formed by a vacuum deposition method, a screen printing method, a plating method, or the like.

For the reflection protective film 107, for example, magnesium fluoride (MgF ₂ ) is used.

The thin film forming apparatus 1 in FIG. 1 forms a light absorption layer 103 by a CIGS film on the substrate 101 in FIG. 2 (the substrate 101 on which the back electrode 102 is formed) or the like.
1 includes a chamber 11, a motor 12, a rotating plate 13, a pump 14, a heater 15, a first vapor deposition source 16, a second vapor deposition source 17, a third vapor deposition source 18, a fourth vapor deposition source 19, and an optical device. It has a film thickness meter (OMS) 20, a crystal film thickness meter (QCM) 21, and a control unit (CTRL) 22.
In the chamber 11, a temperature sensor 23, a probe head 24, and a crystal resonator 25 are disposed.

The chamber 11 has an internal space 11b in the housing 11a.
The chamber 11 has an opening / closing door (not shown) for taking the substrate 101 into and out of the internal space 11b.

The motor 12 is attached to the upper part of the housing 11a of the chamber 11, for example.
And the rotating shaft 12a of the motor 12 penetrates the housing 11a, and protrudes in the internal space 11b.
A rotating plate 13 is attached to the lower end of the rotating shaft 12 a of the motor 12.
The substrate 101 of FIG. 2 is attached to the rotating plate 13.
The motor 12 is connected to the control unit 22.
The motor 12 rotates the rotating plate 13 when a drive signal is input from the control unit 22.

The pump 14 is attached to the left surface of the housing 11a of the chamber 11 in FIG.
The pump 14 is connected to the control unit 22.
When the drive signal is input from the control unit 22, the pump 14 discharges air from the internal space 11b.
Thereby, the inside of the chamber 11 is depressurized and is in a substantially vacuum state.

The heater 15 is attached to the upper part of the inner surface of the housing 11a.
For example, the heater 15 is preferably capable of heating the atmosphere in the chamber 11 and the substrate 101 to about 600 degrees.
The heater 15 is connected to the control unit 22. The heater 15 heats the internal space 11b when a drive signal is input from the control unit 22.
Thereby, the temperature in the chamber 11 rises. The chamber 11 and the substrate 101 are heated.
Further, when the heating by the heater 15 is finished, the temperature in the chamber 11 slowly drops. The chamber 11 and the substrate 101 are cooled.

The temperature sensor 23 is disposed in the housing 11a.
The temperature sensor 23 is attached at the same height as the rotating plate 13.
Thereby, the temperature sensor 23 can detect the temperature of the substrate 101 attached to the rotating plate 13.

The first vapor deposition source 16 includes a first crucible 16a, a first heater 16b, and a first shutter 16c.
Selenium is accommodated in the first crucible 16a.
The selenium in the first crucible 16a evaporates (vaporizes) by the heating of the first heater 16b.
The selenium evaporated from the first crucible 16a diffuses into the chamber 11.
Thereby, evaporated selenium is supplied from the first vapor deposition source 16 into the chamber 11.
The first shutter 16c closes the opening of the first crucible 16a.
Thereby, evaporation of selenium from the first crucible 16a into the chamber 11 is stopped.
The first vapor deposition source 16 receives a drive signal from the control unit. By this drive signal, the first shutter 16c is controlled to open and close, and the selenium heating temperature by the first heater 16b is controlled.
Selenium evaporates from the first vapor deposition source 16 into the chamber 11 at a rate corresponding to the heating temperature. Thereby, the evaporation amount (supply amount) per unit time of selenium, that is, the supply rate is controlled.
In this embodiment, as will be described later, selenium is evaporated during the entire CIGS film formation period. In this case, the first shutter 16c is controlled to be in an open state throughout the CIGS film formation period.

The second vapor deposition source 17 includes a second crucible 17a, a second heater 17b, and a second shutter 17c.
Indium is accommodated in the second crucible 17a.
The indium in the second crucible 17a evaporates (vaporizes) by the heating of the second heater 17b.
Indium evaporated from the second crucible 17 a diffuses into the chamber 11.
Thereby, evaporated indium is supplied from the second vapor deposition source 17 into the chamber 11.
The second shutter 17c closes the opening of the second crucible 17a.
Thereby, the evaporation of indium from the second crucible 17a into the chamber 11 is stopped.
A driving signal from the control unit is input to the second vapor deposition source 17. By this drive signal, the second shutter 17c is controlled to open and close, and the heating temperature of indium by the second heater 17b is controlled.
Indium evaporates from the second vapor deposition source 17 into the chamber 11 at a rate corresponding to the heating temperature. Thereby, the evaporation amount (supply amount) per unit time of indium, that is, the supply rate is controlled.

The third vapor deposition source 18 includes a third crucible 18a, a third heater 18b, and a third shutter 18c.
Gallium is accommodated in the third crucible 18a.
Gallium in the third crucible 18a evaporates (vaporizes) by the heating of the third heater 18b.
The gallium evaporated from the third crucible 18 a diffuses into the chamber 11.
Thereby, evaporated gallium is supplied from the third vapor deposition source 18 into the chamber 11.
The third shutter 18c closes the opening of the third crucible 18a.
Thereby, the evaporation of gallium from the third crucible 18a into the chamber 11 is stopped.
A driving signal from the control unit is input to the third vapor deposition source 18. By this drive signal, the third shutter 18c is controlled to be opened and closed, and the heating temperature of gallium by the third heater 18b is controlled.
Gallium evaporates from the third vapor deposition source 18 into the chamber 11 at a rate corresponding to the heating temperature. Thereby, the evaporation amount (supply amount) per unit time of gallium, that is, the supply rate is controlled.

The fourth vapor deposition source 19 includes a fourth crucible 19a, a fourth heater 19b, and a fourth shutter 19c.
Copper is accommodated in the fourth crucible 19a.
Copper in the fourth crucible 19a evaporates (vaporizes) by the heating of the fourth heater 19b.
Copper evaporated from the fourth crucible 19 a diffuses into the chamber 11.
Thereby, evaporated copper is supplied from the third vapor deposition source 18 into the chamber 11.
The fourth shutter 19c closes the opening of the fourth crucible 19a.
Thereby, the evaporation of copper from the fourth crucible 19a into the chamber 11 is stopped.
The fourth vapor deposition source 19 receives a drive signal from the control unit. By this drive signal, the fourth shutter 19c is controlled to open and close, and the heating temperature of copper by the fourth heater 19b is controlled.
Copper evaporates from the fourth vapor deposition source 19 into the chamber 11 at a rate corresponding to the heating temperature. Thereby, the evaporation amount (supply amount) per unit time of copper, that is, the supply rate is controlled.

FIG. 3 is a schematic configuration diagram of an example of the optical film thickness meter 20 of FIG.
The optical film thickness meter 20 of FIG. 3 includes a halogen lamp 31, an input optical fiber 32, a probe head 24, an output optical fiber 34, a spectroscope 35, and a light receiving unit 36.

The probe head 24 has a measurement plate 33.
The probe head 24 is disposed in the chamber 11.
The probe head 24 is disposed, for example, at a position close to the center of the rotating plate 13.
For example, a compound of indium and selenium, a compound of gallium and selenium, a compound of copper and selenium, and the like adhere to the measurement plate 33.
An adhesion film grows on the surface of the measurement plate 33 due to the deposit 38.

The halogen lamp 31 outputs white light.
White light is light on which light components having a plurality of wavelengths are superimposed.
By using the halogen lamp 31 that outputs white light, it is not necessary to switch the wavelength of the light source during the CIGS film formation period.
One end of the input optical fiber 32 faces the halogen lamp 31. The other end faces the surface on which the adhesion film is formed on the measurement plate 33.
The input optical fiber 32 transmits the white light from the halogen lamp 31 to the probe head 24.
Thereby, white light is irradiated onto the measurement plate 33 and the attached film attached to the measurement plate 33.
One end of the output optical fiber 34 faces the surface on which the adhesion film is formed on the measurement plate 33. The other end is connected to the spectroscope 35.
The output optical fiber 34 transmits the light reflected from the adhesion film and the measurement plate 33 to the spectroscope 35.

The spectroscope 35 has a prism, for example, and separates the light input from the output optical fiber 34 for each wavelength component. The spectroscope 35 extracts a wavelength component for measuring the intensity.
The light receiving unit 36 is a sensor that receives light having a wavelength component extracted by the spectroscope 35.
The light receiving unit 36 detects the intensity of the received wavelength component. This intensity varies depending on the film thickness of the deposit 38 and the wavelength.
The light receiving unit 36 is connected to the control unit 22 and outputs a signal including information on the detected light reception intensity to the control unit 22.

FIG. 4A is an explanatory diagram of the state of incidence and reflection of light on the measurement plate 33 and the deposit 38.
As shown in FIG. 4A, when white light is incident obliquely from above on the measurement plate 33 to which the attached matter 38 is attached, a part of the light is reflected on the surface of the attached matter 38.
Further, the light incident on the deposit 38 is subjected to multiple reflection in the deposit 38.
Part of the multiple reflected light passes through the surface of the deposit 38.
For this reason, the light component reflected at the time of incidence on the surface of the deposit 38 and a part of the light component multiple-reflected by the deposit 38 enter the output optical fiber 34.
Then, a light component reflected at the time of incidence on the surface of the attached matter 38 and a part of the light component reflected multiple times in the attached matter 38 cause a phase difference corresponding to the wavelength and the optical path length difference.
Thereby, the light incident on the output optical fiber 34 becomes stronger or weaker for each wavelength.

Further, the optical path length difference is determined by the thickness of the deposit 38.
For this reason, the light incident on the spectroscope 35 through the output optical fiber 34 has a wavelength spectrum (intensity distribution) having a different intensity for each wavelength of light as shown in FIG. 4B, for example.
In addition, the wavelength spectrum of the light incident on the spectroscope 35 varies depending on the amount of deposit 38, as shown in FIGS.
4B to 4D are explanatory diagrams of an optical spectrum corresponding to the amount of deposit 38 on the measurement plate 33. The horizontal axis is the wavelength. The vertical axis is intensity.
The wavelength spectrum changes from the wavelength spectrum of FIG. 4 (B) to the wavelength spectrum of FIG. 4 (D) when the adhesion amount of the measurement plate 33 increases.

Then, the spectroscope 35 separates the reflected light having a different wavelength spectrum according to the adhesion amount for each wavelength component, and extracts a predetermined wavelength component.
The light receiving unit 36 detects the intensity of the extracted wavelength component light.
The control unit 22 specifies the film thickness of the deposit 38 on the measurement plate 33 based on the light intensity detected by the light receiving unit 36.

FIG. 5 is a schematic configuration diagram of an example of the quartz film thickness meter 21 of FIG.
The crystal film thickness meter 21 in FIG. 5 includes a crystal resonator 25, a transmission circuit 41, a counter 42, and a conversion unit (CVT) 43.

The crystal resonator 25 is connected to the transmission circuit 41. The crystal unit 25 transmits by the power supplied from the transmission circuit 41.
The oscillation frequency of the crystal unit 25 is stable and generally has an accuracy of the order of 8 digits.
The crystal resonator 25 is disposed in the chamber 11.
The crystal unit 25 is arranged side by side with the probe head 24 at a position close to the center of the rotating plate 13, for example.
For example, a compound of indium and selenium, a compound of gallium and selenium, a compound of copper and selenium, or the like adheres to the crystal unit 25 disposed in the chamber 11.

FIG. 6 is an explanatory diagram of the frequency characteristics corresponding to the amount of deposit 44 of the crystal resonator 25 of FIG.
The horizontal axis is frequency. The vertical axis represents the conductance of the crystal unit 25.
Then, as exemplified by f1, f2, and f3 in FIG. 6, the oscillation frequency of the crystal resonator 25 changes according to the amount of the deposit 44 attached.
Specifically, the transmission frequency of the crystal unit 25 decreases as the amount of deposit 44 increases.

The transmission circuit 41 is connected to the counter 42.
The transmission circuit 41 supplies power to the crystal unit 25, amplifies the vibration signal generated by the crystal unit 25, and outputs the amplified signal to the counter 42.
The counter 42 counts the period of the vibration signal input from the transmission circuit 41 every unit time.
The counter 42 is connected to the conversion unit 43 and outputs the count value to the conversion unit 43.
The conversion unit 43 converts the count value into the film thickness value of the deposit 44 attached to the crystal unit 25 based on the frequency change characteristic data of FIG.
The conversion unit 43 is connected to the control unit 22 in FIG. 1, and outputs a signal including the converted film thickness value of the deposit 44 of the crystal resonator 25 to the control unit 22.
Since the oscillation frequency of the crystal unit 25 is stable, the film thickness value output to the control unit 22 has high accuracy.

FIG. 7 shows a computer apparatus 50 as an example of the control unit 22 of FIG.
7 includes a CPU (Central Processing Unit) 51, a memory (MEM) 52, an operation unit (KEY) 53, a display unit (DISP) 54, an input / output port (I / O) 55, and a connection between them. System bus 56.

The memory 52 stores a program for executing a flowchart of a thin film manufacturing process shown in FIG. 9 to be described later.
The CPU 51 reads a program from the memory 52 and executes it.
Thereby, the CPU 51 functions as the control unit 22 of the thin film forming apparatus 1.
And CPU51 as the control part 22 of the thin film formation apparatus 1 will start a thin film manufacturing process, if the film thickness, composition ratio, etc. of the CIGS film (light absorption layer 103) to form are input from the operation part 53, for example. .
During the thin film manufacturing process, the CPU 51 displays measurement data shown in FIG. 10 or FIG.

The input / output port 55 is connected to the pump 14, the heater 15, the motor 12, the first vapor deposition source 16, the second vapor deposition source 17, the third vapor deposition source 18, and the fourth vapor deposition source 19.
The control unit 22 outputs a control signal to these devices.
The input / output port 55 is connected to the temperature sensor 23, the optical film thickness meter 20, and the crystal film thickness meter 21.
Then, the control unit 22 detects the temperature of the chamber 11 and the substrate 101 detected by the temperature sensor 23, the film thickness of the deposit 38 on the measurement plate 33 detected by the optical film thickness meter 20, and the crystal film thickness meter 21. Based on the film thickness of the deposit 44 of the quartz crystal resonator 25, control is performed to form a CIGS film having a desired film thickness and a desired composition ratio on the substrate 101.

FIG. 8 is a comparison diagram between the output characteristics of the optical film thickness meter (OMS) 20 and the output characteristics of the crystal film thickness meter (QCM) 21.
The upper stage of FIG. 8 shows output characteristics when selenium and metal (copper, indium, or gallium) are present in the chamber 11.
The lower part of FIG. 8 shows the output characteristics when only selenium is present in the chamber 11.
The output characteristics of FIG. 8 are output characteristics when the temperature in the chamber 11 is about 200 degrees or more.

When the temperature in the chamber 11 is, for example, normal temperature, the selenium evaporated in the chamber 11 can adhere to the measurement plate 33 of the optical film thickness meter 20 or the crystal resonator 25 of the crystal film thickness meter 21.
However, when the temperature in the chamber 11 is about 200 ° C. or more, the selenium in the vacuum chamber 11 is immediately attached to the measurement plate 33 of the optical film thickness meter 20 or the crystal resonator 25 of the crystal film thickness meter 21. Evaporate.
That is, selenium cannot be deposited and grown on the substrate 101 or the like.
For this reason, at about 200 degrees or more, the deposit 38 does not grow on the measurement plate 33 of the optical film thickness meter 20 in the chamber 11.
If the deposit 38 does not grow, light thin film interference does not occur on the measurement plate 33.
As a result, when only selenium is present in the chamber 11 of about 200 degrees or more, the quartz film thickness meter 21 can measure the amount of selenium in the chamber 11 as shown in the lower part of FIG. 20 cannot measure the amount of selenium in the chamber 11.

When selenium and metal are evaporated in the chamber 11, a compound of selenium and metal is combined in the chamber 11.
This compound adheres to the measurement plate 33 of the optical film thickness meter 20 or the crystal resonator 25 of the crystal film thickness meter 21 even when the inside of the chamber 11 is about 200 degrees or more.
Further, the deposit 38 grows on the measurement plate 33 of the optical film thickness meter 20.
For this reason, when selenium and metal exist in the chamber 11 of about 200 degrees or more, the deposit 38 grows on the measurement plate 33. Then, as shown in the upper part of FIG. 8, the film thickness of the deposit 38 grown on the substrate 101 can be measured by the optical film thickness meter 20.
When selenium and metal are present in the chamber 11 at about 200 degrees or more, the amount of deposits 38 and 44 in the chamber 11 and the supply amount can be measured by the crystal film thickness meter 21 and the optical film thickness meter 20.

  The controller 22 controls the composition ratio of the CIGS film grown on the substrate 101 with high accuracy by using the quartz film thickness meter 21 and the optical film thickness meter 20 having such output characteristics in a suitable combination. . The control unit 22 controls the thickness of the CIGS film grown on the substrate 101 with high accuracy.

Next, a thin film manufacturing method using the thin film forming apparatus 1 of FIG. 1 will be described.
In the following description of the manufacturing method, a case where a CIGS film (light absorption layer 103) is formed with a desired film thickness and a desired composition ratio on the substrate 101 (the substrate 101 on which the back electrode 102 is formed) in FIG. Explained as an example.

FIG. 9 is an overall flowchart of an example of a thin film manufacturing process executed by the control unit 22 of the thin film forming apparatus 1 of FIG. FIG. 9 is an example of a thin film manufacturing process based on the three-stage method.
The thin film manufacturing process of FIG. 9 is executed by, for example, the control unit 22 of FIG.
Note that the thin film manufacturing process of FIG. 9 may be executed based on a manual operation on the control unit 22.

FIG. 10 is a time chart of the entire thin film manufacturing process by the three-stage method of FIG. The horizontal axis is time (in seconds). The vertical axis is temperature.
A characteristic curve C <b> 1 (Temp) in FIG. 10 is a temperature characteristic curve of the substrate 101 in the chamber 11 detected by the temperature sensor 23.
For the sake of explanation, FIG. 10 also shows a characteristic curve C1 (OMS) of the output characteristic of the optical film thickness meter 20 and a characteristic curve C2 (QCM) of the output characteristic of the crystal film thickness meter 21.

As shown in FIG. 10, in the three-stage method using the thin film forming apparatus 1 of FIG. 1, after the heating period in which the inside of the chamber 11 is heated to a predetermined temperature (200 ° C. or more), It becomes a production period.
The CIGS film manufacturing period by the three-stage method includes a first period T1 for forming a thin film made of indium, gallium and selenium, a second period T2 for forming a thin film made of copper and selenium, and a thin film made of indium, gallium and selenium. The third period T3.

As shown in FIG. 10, in the first period T1 to the third period T3, the detection value of the optical film thickness meter 20 takes a plurality of peak values.
Specifically, in FIG. 10, the detected value of the optical film thickness meter 20 has eight peaks from P1 to P8 in the first period T1. In the second period T2, four peaks from P9 to P12 are obtained. In the third period T3, there are two peaks from P13 to P14.
The number of peaks in the second period T2 with respect to the number of peaks in the sum of the number of peaks in the first period T1 and the number of peaks in the third period T3 is the composition ratio of copper to indium and gallium.
Each time the optical film thickness meter 20 detects this peak, the optical film thickness meter 20 switches the operating state of the optical film thickness meter 20, for example, the wavelength used for detection.
Further, after the manufacturing period of the CIGS film by the three-stage method, there are an annealing and cooling period.

FIG. 11 is a time chart in which the period A during the thin film manufacturing process of FIG. 10 is enlarged.
The horizontal axis in FIG. 11 is time. The vertical axis on the left side of FIG. 11 is the output value of the optical film thickness meter 20. This output value is expressed as a percentage. The vertical axis on the right side of FIG. 11 is the output value of the quartz film thickness meter 21. This output value is a rate (A / s) display.
FIG. 11 shows an output characteristic characteristic curve C1 (OMS) of the optical film thickness meter 20 and an output characteristic characteristic curve C2 (QCM) of the quartz film thickness meter 21.

A period A in FIG. 10 is a period after the heating step. The period A is a period before starting the thin film formation with indium, gallium and selenium in the first step.
FIG. 11 shows a period until the optical film thickness meter 20 takes the first peak P1 in the first step.

  The detected value of the quartz film thickness meter 21 changes from the base rate L1 to the formation rate L2 during the first period T1. The base rate L1 is a detection value level in an atmosphere in which only selenium is evaporated in the chamber 11. The formation rate L2 is a detection value level in an atmosphere in which indium, gallium, and selenium are evaporated in the chamber 11.

  Further, the detection value of the quartz film thickness meter 21 has a plurality of rectangular waveforms during the period of the base rate L1. In FIG. 11, the low rectangular waveform and the high rectangular waveform appear alternately.

In the rectangular waveform having a low protrusion amount from the base rate L1, only the third shutter 18c of the third vapor deposition source 18 is opened in the selenium atmosphere, and only gallium is evaporated at a predetermined supply rate R (Ga). Is a rectangular waveform.
When gallium is evaporated in the selenium atmosphere, a compound of gallium and selenium (Ga ₂ Se ₃ ) is generated and adheres to the substrate 101, the measurement plate 33, and the crystal unit 25.
For this reason, the gallium compound supplied at the supply rate R (Ga) adheres to the crystal unit 25, the oscillation frequency of the crystal unit 25 changes, and a low rectangular waveform appears at the output of the crystal film thickness meter 21. appear.
Then, as indicated by hatching in the lower rectangular waveform at the right end in FIG. 11, the height (relative rate) of the lower rectangular waveform protruding from the base rate L1 enters the chamber 11 at a predetermined supply rate R (Ga). Corresponds to the supplied amount of gallium.

In the rectangular waveform having a high protrusion amount from the base rate L1, only the second shutter 17c of the second vapor deposition source 17 was opened in the selenium atmosphere, and only indium was evaporated at a predetermined supply rate R (In). Is a rectangular waveform.
When indium is evaporated in the selenium atmosphere, a compound of indium and selenium (In ₂ Se ₃ ) is generated and adheres to the substrate 101, the measurement plate 33, and the crystal unit 25.
For this reason, the gallium compound supplied at the supply rate R (In) adheres to the crystal unit 25, the oscillation frequency of the crystal unit 25 changes, and a high rectangular waveform appears at the output of the crystal film thickness meter 21. appear.
Then, as shown by hatching in the high rectangular waveform at the right end in FIG. 11, the height (relative rate) of the high rectangular waveform protruding from the base rate L1 enters the chamber 11 at a predetermined supply rate R (In). This corresponds to the supplied amount of indium.

In this way, during the base rate L1, indium and gallium are alternately and intermittently supplied into the chamber 11, and the amount of the deposited compound is measured using the quartz film thickness meter 21, thereby enabling the environment of the first step. Below, the supply amount of indium and the supply amount of gallium supplied into the chamber 11 can be measured with high accuracy.
Further, the composition ratio of indium and gallium can be adjusted with high accuracy by the height ratio between the height of the high rectangular waveform and the height of the low rectangular waveform in FIG.

As shown in FIG. 9, when a CIGS film is formed on the substrate 101, the composition ratio, film thickness, and the like of the CIGS thin film are input to the control unit 22 from the operation unit 53 (step ST1).
Thereby, the control part 22 starts a thin film manufacturing process.

When the thin film manufacturing process is started, the control unit 22 determines parameters in each step of the three-stage method based on the input composition ratio and film thickness (step ST2).
The parameters in the first step include indium supply rate, gallium supply rate, and the number of detection peaks of the optical film thickness meter 20.
The parameter in the second step includes the number of detection peaks of the optical film thickness meter 20.
The parameters in the third step include indium supply rate, gallium supply rate, and the number of detection peaks of the optical film thickness meter 20.

These parameters may be determined as follows, for example.
The film thickness grown on the measurement plate 33 is substantially the same as the film thickness grown on the substrate 101.
The output peak level (film thickness on the measurement plate 33) that can be detected by the optical film thickness meter 20 is also known in advance.
Therefore, for example, the number of peaks detected by the optical film thickness meter 20 in each process is determined from the total film thickness of the CIGS film formed on the substrate 101.
The controller 22 determines the number of detected peaks of the optical film thickness meter 20 in each step of the three-stage method. Thereby, the supply peak number by the 2nd process which supplies copper with respect to the total detection peak number of the 1st process and 3rd process which supplies indium and gallium is determined.
FIG. 10 shows an example in which the total number of detected peaks when supplying indium and gallium is 10 (= 8 + 2) and the number of detected peaks when supplying copper is four. In this case, the composition ratio of copper to indium and gallium is 4/10.

Moreover, the control part 22 determines the total supply amount of each component in each process from the composition ratio of a CIGS film | membrane. Moreover, the control part 22 determines the supply rate of each component in each process. Thereby, the supply rate of indium and the supply rate of gallium are determined.
Further, the controller 22 determines the heating temperatures of the first vapor deposition source 16, the second vapor deposition source 17, the third vapor deposition source 18, and the fourth vapor deposition source 19 from the supply rate of each component.
Through the above arithmetic processing, the control unit 22 determines control parameters (control target values) in the first step, the second step, and the third step.

After determining the control target value in step ST2, the control unit 22 starts actual control.
The control unit 22 drives the motor 12 to rotate the rotating plate 13 and the substrate 101. Further, the control unit 22 outputs a drive signal to the pump 14 to depressurize the chamber 11. Moreover, the control part 22 outputs a drive signal to the heater 15, and heats the inside of the chamber 11 (step ST3). Thereby, the temperature in the chamber 11 is heated to the temperature shown in the heating period of FIG. In FIG. 10, it is heated to about 300 degrees.
Moreover, the control part 22 heats the 1st vapor deposition source 16, the 2nd vapor deposition source 17, the 3rd vapor deposition source 18, and the 4th vapor deposition source 19 to each heating temperature.

When the heating process ends, the control unit 22 starts the first process.
Since the temperature at the end of this heating step is 200 ° C. or more, the selenium evaporated in the chamber 11 does not reach a saturated vapor pressure.
In the first step, first, the control unit 22 supplies the indium supply rate and the gallium supply so that the actual gallium supply amount and the indium supply amount become the desired gallium supply amount and the indium supply amount. Adjust the rate.
Specifically, the control unit 22 opens and closes the third shutter 18c of the third vapor deposition source 18 (step ST4).
Thereby, gallium is supplied into the chamber 11 at a supply rate corresponding to the heating temperature.
Thereafter, the control unit 22 acquires the output of the quartz film thickness meter 21 (step ST5).
At this time, the output value of the quartz film thickness meter 21 is the first low rectangular waveform in FIG.
Subsequently, the control unit 22 opens and closes the second shutter 17c of the second vapor deposition source 17 (step ST6).
Thereby, indium is supplied into the chamber 11 at a supply rate corresponding to the heating temperature.
Then, the control part 22 acquires the output of the quartz film thickness meter 21 (step ST7).
The output value of the quartz crystal thickness meter 21 at this time is the first high rectangular waveform in FIG.
From the height of the first rectangular waveform in FIG. 11 detected by the quartz film thickness meter 21 and the height of the high rectangular waveform, the control unit 22 actually supplies evaporated gallium, supplied indium, and These ratios are calculated (step ST8).
Further, the control unit 22 determines whether or not the ratio and the supply amount based on the measurement correspond to the composition ratio of each component input in step ST1 (step ST9).

If the measured ratio does not correspond to the composition ratio, the control unit 22 adjusts the indium supply rate and the gallium supply rate (step ST10).
Specifically, the control unit 22 adjusts the temperature of the second vapor deposition source 17 and the temperature of the third vapor deposition source 18.
For example, when the supply rate of gallium is higher than the supply rate of indium, the control unit 22 raises the temperature of the second heater 17b of the second evaporation source 17. Alternatively, the control unit 22 decreases the temperature of the third heater 18 b of the third vapor deposition source 18.
The controller 22 repeats the adjustment process of steps ST4 to ST10 until a supply ratio corresponding to a desired composition ratio is obtained in step ST9.
With this adjustment process, the quartz film thickness meter 21 detects a high rectangular waveform and a low rectangular waveform alternately during the base rate period of FIG.
In FIG. 11, the above adjustment process is repeated eight times during the base rate period.

When a desired indium supply rate and a gallium supply rate suitable for the composition ratio of indium and gallium are obtained by adjusting the heating temperature of the vapor deposition source in steps ST4 to ST10, the control unit 22 applies the substrate 101 to the substrate 101. The process for forming the first film is started (step ST11).
The controller 22 opens the second shutter 17c of the second vapor deposition source 17, and opens the third shutter 18c of the third vapor deposition source 18 (step ST12). Thereby, indium and gallium are supplied at a supply rate according to their composition ratio.
As a result, the output of the quartz film thickness meter 21 changes from the base rate L1 to the formation rate L2 as shown in FIG.
Moreover, the control part 22 acquires the output of the optical film thickness meter 20 (step ST13).
And the control part 22 judges whether the output value of the optical film thickness meter 20 showed the peak value (step ST14).
An adhesion film grows on the measurement plate 33 in the same manner as the substrate 101.
The output value of the optical film thickness meter 20 increases according to the film thickness of the deposit 38 that grows on the measurement plate 33.
And when time passes after supply of indium and gallium starts, the output value of the optical film thickness meter 20 shows a peak value.

The output peak value of the optical film thickness meter 20 also varies depending on the film thickness composition of the deposit 38 that grows on the measurement plate 33. In this case, it varies depending on the composition ratio of the compound of indium and selenium and the compound of gallium and selenium. This is because these materials have different characteristics such as refractive index.
For this reason, the control part 22 may confirm whether an output peak value is a value of a desired composition ratio in step ST14. Further, when the output peak value is not the desired composition ratio, the control unit 22 adjusts the indium supply rate and the gallium supply rate so that the output peak value approaches the desired composition ratio. Also good.

When the output value of the optical film thickness meter 20 shows a peak value, the control unit 22 counts the number of detected peaks, and determines whether or not this count value matches the number of peaks in the first step (Step S22). ST15).
The control unit 22 repeats steps ST12 to ST15 until a predetermined number of peaks are counted.
And the control part 22 will complete | finish a 1st process, if the peak number of 8 times from P1 to P8 is counted as shown in FIG.
The control unit 22 closes the second shutter 17c and the third shutter 18c.
As a result, a first film made of a compound of indium and selenium and a compound of gallium and selenium is formed on the substrate 101 with a desired film thickness and composition ratio.

When the first step is finished, the control unit 22 starts the second step (step ST16).
In the second step, the control unit 22 opens the fourth vapor deposition source 19.
Thereby, copper is supplied into the chamber 11.
Moreover, the control part 22 starts the heating by the heater 15, as shown in FIG.
Thereby, the temperature in the chamber 11 begins to rise slowly.
Further, the control unit 22 acquires the output of the optical film thickness meter 20.
And the control part 22 judges whether the output value of the optical film thickness meter 20 showed the peak value.

An adhesion film grows on the measurement plate 33 in the same manner as the substrate 101.
The output value of the optical film thickness meter 20 increases according to the film thickness of the deposit 38 that grows on the measurement plate 33.
And when time passes after supply of copper starts, the output value of the optical film thickness meter 20 shows a peak value.
When the output value of the optical film thickness meter 20 shows a peak value, the control unit 22 counts the number of detected peaks, and determines whether or not this count value matches the number of peaks in the second step.
And the control part 22 will complete | finish a 2nd process, if the peak number of 8 times from P9 to P12 is counted, as shown in FIG. The control unit 22 closes the fourth vapor deposition source 19.
Thereby, a second film made of a compound of copper and selenium is formed on the first film with a desired film thickness and composition ratio.

When the second step is finished, the control unit 22 starts the third step (step ST17).
In the third step, the controller 22 opens the second shutter 17 c of the second vapor deposition source 17 and the third shutter 18 c of the third vapor deposition source 18. Thereby, indium and gallium are supplied at the supply rate adjusted in the first step.
Further, the control unit 22 acquires the output of the optical film thickness meter 20.
And the control part 22 judges whether the output value of the optical film thickness meter 20 showed the peak value.
An adhesion film grows on the measurement plate 33 in the same manner as the substrate 101.

The output value of the optical film thickness meter 20 increases according to the film thickness of the deposit 38 that grows on the measurement plate 33.
And when time passes after supply of indium and gallium starts, the output value of the optical film thickness meter 20 shows a peak value.
When the output value of the optical film thickness meter 20 indicates a peak value, the control unit 22 counts the number of detected peaks, and determines whether or not this count value matches the number of peaks in the third step.
And the control part 22 will complete | finish a 3rd process, if the number of peaks of 2 times from P13 to P14 is counted, as shown in FIG.
The control unit 22 closes the second shutter 17c and the third shutter 18c.
Thereby, a third film made of a compound of indium and selenium and a compound of gallium and selenium is formed on the second film with a desired film thickness and composition ratio.

When the third step is finished, the control unit 22 performs annealing and cooling processing (steps ST18 and ST19).
In the annealing and cooling process, the control unit 22 continues heating by the heater 15.
When the temperature in the chamber 11 reaches about 550 degrees, the control unit 22 ends the heating by the heater 15.
Thereafter, the control unit 22 performs natural cooling.
Thereby, the temperature in the chamber 11 falls to about 200 degrees.
The controller 22 ends the cooling process before the temperature in the chamber 11 becomes 200 degrees or less.
The control unit 22 stops the motor 12.
When the cooling process is completed, the substrate 101 is taken out from the chamber 11.

In the present embodiment, a CIGS film is formed on the substrate 101 by the above thin film manufacturing process.
In the present embodiment, the crystal thickness meter 21 is used at the beginning of the first step of the three-stage method so that the actual supply amount of indium, the actual supply amount of gallium, and the ratio thereof become target values. adjust.
Thereby, the composition ratio in the CIGS film formed on the substrate 101 in this embodiment coincides with the composition ratio set in the control unit 22 with high accuracy.

In the present embodiment, the film thickness formed on the measurement plate 33 is detected by the optical film thickness meter 20 in all the steps from the first step to the third step of the three-stage method, and each step is performed according to the detected number of peaks. The film thickness to be formed is controlled.
Thereby, the film thickness of the CIGS film formed on the substrate 101 in this embodiment coincides with the film thickness set in the control unit 22 with high accuracy.

In this embodiment, for example, the film thickness of the compound of copper and selenium can be controlled with 1 nanometer accuracy by the monitor wavelength of the optical film thickness meter 20.
In the present embodiment, the combination of the optical film thickness meter 20 and the quartz film thickness meter 21 can control the Cu / (In + Ga), Ca / (In + Ga) composition ratio in the CIGS film on the order of 1/1000.

On the other hand, for example, in the conventional three-stage method or four-source simultaneous vapor deposition method, film thickness control using the optical film thickness meter 20 and time control are common.
These conventional methods cannot control the composition ratio of the CIGS film with high accuracy.
In addition, with the time control, the thickness of the CIGS film cannot be controlled with high accuracy.

  The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications or changes can be made without departing from the scope of the invention.

For example, in the above embodiment, the CIGS film (light absorption layer 103) is formed by a three-stage method as shown in FIG.
In addition, for example, a CIGS film (light absorption layer 103) may be formed by a four-source simultaneous vapor deposition method.
In this case, the controller 22 adjusts the supply rate of gallium, the supply rate of indium, and the supply rate of copper according to a desired composition ratio at the beginning of the quaternary co-evaporation process after heating, and the adjusted supply The quaternary supply may be performed at a rate.

The thin film forming apparatus 1 of the above embodiment forms a CIGS film (light absorption layer 103) in the chamber 11 as shown in FIG. The thin film forming apparatus 1 in FIG. 1 is a batch type.
In addition, for example, the present invention can be applied to the thin film forming apparatus 1 that forms the CIGS film (light absorption layer 103) by a continuous process.
For example, when the CIGS film formation is started by the continuous process thin film forming apparatus 1, the gallium supply rate, the indium supply rate, and the copper supply rate may be adjusted.

In the above-described embodiment, the CIGS film (light absorption layer 103) is formed as a thin film.
In addition to this, for example, the thin film forming apparatus 1 and the method of the present invention can be applied to the case of forming a CIS film or a CIG film.
In addition to selenium, sulfur, arsenic, phosphorus, or the like may be used as a substance to be evaporated in the chamber before supplying the metal.
By supplying the metal into the chamber 11 in a state where the substance to be evaporated in the chamber is heated to a temperature at which the saturated vapor pressure is not reached before supplying the metal, a compound with the metal is generated, and a thin film made of the compound or the like Can be grown on the substrate.

DESCRIPTION OF SYMBOLS 1 ... Thin film formation apparatus (manufacturing apparatus of a multi-source vapor deposition thin film), 11 ... Chamber, 15 ... Heater, 16 ... 1st vapor deposition source (1st supply part), 16c ... 1st shutter, 17 ... 2nd vapor deposition source (1st 2 supply part), 17c ... 2nd shutter, 18 ... 3rd vapor deposition source (3rd supply part), 18c ... 3rd shutter, 19 ... 4th vapor deposition source (4th supply part), 19c ... 4th shutter, 20 ... Optical film thickness meter (film thickness detection unit), 21 ... Quartz film thickness meter (adhesion amount detection unit), 22 ... Control unit, 25 ... Crystal resonator (vibrator), 33 ... Measurement plate, 101 ... Substrate, 103 ... light absorption layer (CIGS layer), T1 ... first period (first process period), T2 ... second period (second process period), T3 ... third period (third process period), T ( In) ... first measurement period (period of the first measurement process), T (Ga) ... second measurement period (period of the second measurement process)

Claims (8)

A method of controlling composition of a multi-source vapor deposition thin film by depositing a thin film of at least four substances on the substrate by supplying a first substance and at least three substances to a substrate housed in a chamber,
In the state where the first substance is supplied into the chamber and the inside of the chamber is heated to a temperature at which the first substance does not adhere to the substrate.
Among the at least three component substances, the composition ratio of two or more substances supplied into the chamber in the same film forming step is changed to a change in oscillation frequency due to an adhering substance of a vibrator disposed in the chamber. Control by detecting based on
Among the at least three component substances, the composition ratio of two or more substances supplied into the chamber in different stages in different film forming steps is used to determine the film thickness of the deposit on the measuring plate disposed in the chamber. The composition control method of the multi-source vapor deposition thin film is controlled by detecting light by thin film interference of light. The first substance is
The composition control method for a multi-source deposited thin film according to claim 1, wherein the material is not saturated in the chamber at the heated temperature. The first substance is
The composition control method for a multi-source vapor deposition thin film according to claim 2, wherein the composition is selenium, sulfur, arsenic, or phosphorus. The first substance is selenium;
The at least three materials are indium, gallium, and copper;
The composition control method of a multi-source vapor deposition thin film according to claim 1, wherein the thin film deposited on the substrate is a CIGS film that generates power by absorbing sunlight. A chamber containing a substrate on which a thin film including at least four component substances including a first substance, a second substance, a third substance, and a fourth substance is formed;
A first supply unit for supplying the first substance to the chamber;
A second supply unit for supplying the second substance to the chamber;
A third supply unit for supplying the third substance to the chamber in the same film forming step as the second substance;
A fourth supply unit for supplying the fourth substance to the chamber in a film forming process different from the second substance and the third substance;
The vibrator has a vibrator disposed in the chamber, and detects the amount of deposits attached to the vibrator based on a change in the oscillation frequency of the vibrator caused by the deposits attached to the vibrator. An adhesion amount detection unit;
A film thickness detector that includes a measurement plate disposed in the chamber, and detects a film thickness of an adhering substance attached to the measurement plate by light thin film interference;
A heater for heating the inside of the chamber,
The first material is supplied into the chamber, the chamber is heated to a temperature at which the first material does not adhere to the substrate by the heater, and the second material and the third material are sequentially added to the chamber. The composition ratio of the second substance and the third substance is controlled based on the adhesion amount detected by the adhesion amount detection unit when supplied into the chamber,
The first substance is supplied into the chamber, the inside of the chamber is heated to a temperature at which the first substance does not adhere to the substrate by the heater, and the second substance and the third substance are supplied into the chamber. In this case, based on the film thickness detected by the film thickness detector and the film thickness detected by the film thickness detector when the fourth substance is supplied into the chamber, the second substance and the An apparatus for producing a multi-source vapor deposition thin film in which a composition ratio of the fourth substance to a third substance is controlled. The multi-source vapor deposition thin film manufacturing apparatus comprises:
A control unit for controlling the first supply unit, the second supply unit, the third supply unit, the fourth supply unit, and the heater;
The controller is
With the first substance supplied from the first supply unit into the chamber, the heater heats the chamber to a heating temperature at which the first substance does not adhere to the substrate,
Supplying the second substance from the second supply unit at a temperature equal to or higher than the heating temperature, and causing the adhesion amount detection unit to detect the adhesion amount of the deposit based on the second substance;
Supplying the third substance from the third supply unit at a temperature equal to or higher than the heating temperature, and causing the adhesion amount detection unit to detect an adhesion amount of the deposit based on the third substance;
Based on the adhesion amount of the deposit based on the second substance detected by the adhesion amount detection unit and the adhesion amount of the deposit based on the third substance, the second substance and the third substance are predetermined. The supply rate of the second substance and the supply rate of the third substance are changed so that the composition ratio becomes
The apparatus for producing a multi-source vapor deposition thin film according to claim 5, wherein the second material and the third material are simultaneously supplied at the changed supply rate to form a thin film on the substrate. The controller is
With the first substance supplied from the first supply unit into the chamber, the heater heats the chamber to a heating temperature at which the first substance does not adhere to the substrate,
The second material and the third material are simultaneously supplied from the second supply unit and the third supply unit at a temperature equal to or higher than the heating temperature, and a film made of the second material and the third material is deposited on the substrate. Let
Supplying the fourth substance from the fourth supply unit at a temperature equal to or higher than the heating temperature, and depositing a film of the fourth substance on the substrate;
The film thickness of the deposit detected by the film thickness detector during the period in which the film of the second substance and the third substance is deposited on the substrate, and the period in which the film of the fourth substance is deposited on the substrate. The apparatus for producing a multi-source vapor deposition thin film according to claim 6, wherein the composition ratio of the fourth substance to the second substance and the third substance is controlled based on the film thickness of the deposit detected by the film thickness detector. . The first substance is selenium;
The second material is indium;
The third substance is gallium;
The fourth material is copper;
The apparatus for producing a multi-source vapor deposition thin film according to any one of claims 5 to 7, wherein the thin film deposited on the substrate is a CIGS film that generates power by absorbing sunlight.

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