JP2012117127A - Film deposition device, film deposition substrate manufacturing method, and film deposition substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film deposition device which can deposit a molybdenum layer suitably removable when performing patterning using a LASER scribe method, and a film deposition substrate manufacturing method and a film deposition substrate.SOLUTION: In a film deposition chamber 11B, a pressure gradient of inert gas is generated from upstream side to downstream side along the substrate transfer direction D. This pressure gradient is formed such that the inert gas pressure of upstream side is higher than the inert gas pressure of downstream side. By performing film deposition of molybdenum layer in the film deposition chamber 11B having the pressure gradient, the molybdenum layer having metal density gradient along the substrate side to the surface side can be deposited. In this metal density gradient, along the thickness direction of the molybdenum layer, the density gradient is formed such that the density may become lower accompanied by approaching from the surface side into the substrate side. If the LASER scribe method is applied to the molybdenum layer having such a density gradient, the molybdenum layer can be suitably removed.

Description

  The present invention relates to a film formation apparatus, a method for manufacturing a film formation substrate, and a film formation substrate.

  Conventionally, a film formation substrate in which Cu is formed as a metal film on a substrate is known (see Patent Document 1). In such a film formation substrate, as shown in FIG. 7A, a low density film region 101 is thinly deposited immediately above the substrate, and a high density film region 102 is thickly deposited on the low density film region. ing. Further, as shown in FIG. 7B, a film formation substrate is known in which a film region 103 having a constant density is formed on a substrate.

JP 11-315374 A

  However, when a molybdenum layer is formed on a substrate using a conventional film formation method and patterned by applying the LASER scribe method to this film formation substrate, the film thickness region to be removed is not sufficiently removed and the residue May occur.

  FIG. 6B shows an SEM photograph after the LASER scribe method is applied to a conventional film formation substrate. As shown in FIG. 6B, when the LASER scribing method is applied to a conventional film formation substrate, a residue is generated, and there is a possibility that adjacent film formation regions are electrically connected to each other with the removal region interposed therebetween. is there.

  The present invention has been made to solve such problems, and provides a film forming apparatus capable of forming a molybdenum layer which can be suitably removed when patterning is performed using the LASER scribe method. Objective.

  In addition, the present invention has been made to solve such problems, and a method for manufacturing a deposition substrate capable of forming a molybdenum layer that can be suitably removed when patterning is performed using the LASER scribe method. The purpose is to provide.

  In addition, the present invention has been made to solve such problems, and provides a deposition substrate on which a molybdenum layer that can be suitably removed when patterning is performed using the LASER scribe method. For the purpose.

  As a result of intensive studies to achieve the above object, the present inventors have provided a metal density gradient in the film thickness direction of the molybdenum layer so that the density decreases as it approaches the substrate side from the surface side of the molybdenum layer. It was found that the molybdenum layer can be suitably removed when patterning using the LASER scribe method by forming a molybdenum layer.

  Therefore, a film forming apparatus according to the present invention is a film forming apparatus for forming a molybdenum layer on a substrate, and a film forming material for forming the molybdenum layer is provided, and the molybdenum layer is formed on the substrate. An inert gas is introduced into the film chamber and the film formation chamber, and the pressure of the inert gas in the film formation chamber is reduced from the first pressure state to a second pressure state lower than the first pressure state. A pressure gradient forming means capable of forming a pressure gradient, and the film formation chamber is formed in a first pressure state in an atmosphere in which the pressure of the inert gas decreases along the pressure gradient, It is characterized by forming a film in a pressure state.

  In such a film forming apparatus, a pressure gradient is generated that lowers the pressure of the inert gas in the film forming chamber from the first pressure state to a second pressure state lower than the first pressure state. The pressure gradient may be a pressure gradient according to the position in the transport direction or a pressure gradient according to the passage of time. By forming a molybdenum layer in a film formation chamber in which such a pressure gradient has occurred, a molybdenum layer having a metal density gradient formed from the substrate side to the surface side can be formed. This metal density gradient increases with increasing distance from the substrate side. In other words, in the film thickness direction of the molybdenum layer, a density gradient is formed so that the density decreases as it approaches the substrate side from the surface side. When the LASER scribe method is applied to the molybdenum layer having such a density gradient, the molybdenum layer is preferably removed. Since the density of the molybdenum layer decreases as the depth increases from the surface side, the molybdenum layer can be suitably removed even when the LASER intensity is attenuated according to the depth, and good pattern formation is realized. Here, the “density of the molybdenum layer” refers to the distribution ratio of molybdenum per unit area or the mass of molybdenum per unit volume. same as below.

  The film forming apparatus further includes a substrate transfer means for transferring the substrate in the film forming chamber, and the pressure gradient forming means sets the upstream side in the substrate transfer direction to the first pressure state and the downstream side in the substrate transfer direction to the first pressure state. It is preferable to form a pressure gradient with a pressure state of 2.

  In such a film forming apparatus, a pressure gradient of an inert gas (argon gas) is generated in the film forming chamber from the upstream side to the downstream side in the substrate transport direction. This pressure gradient is formed such that the upstream inert gas pressure is high and the downstream inert gas pressure is low. By forming a molybdenum layer in a film formation chamber in which such a pressure gradient has occurred, a molybdenum layer having a metal density gradient formed from the substrate side to the surface side can be formed. This metal density gradient increases with increasing distance from the substrate side. In other words, in the film thickness direction of the molybdenum layer, a density gradient is formed so that the density decreases as it approaches the substrate side from the surface side. When the LASER scribe method is applied to the molybdenum layer having such a density gradient, the molybdenum layer is preferably removed. Since the density of the molybdenum layer decreases as the depth increases from the surface side, the molybdenum layer can be suitably removed even when the LASER intensity is attenuated according to the depth, and good pattern formation is realized.

  In addition, a plurality of film forming materials are arranged in the substrate transport direction, and a gas inlet for introducing an inert gas into the film forming chamber is provided upstream of the central film forming material in the substrate transport direction. It is suitable. Thus, when a plurality of film forming materials are provided, an inert gas is introduced upstream of the center in the substrate transport direction of the plurality of film forming materials, so that the inert gas on the upstream side The pressure gradient can be formed so that the pressure is high and the pressure of the inert gas downstream is low.

  Further, it is preferable that a gas introduction port for introducing an inert gas into the deposition chamber is provided on the upstream side of the deposition material. In this way, by introducing an inert gas upstream of the film forming material, a pressure gradient is formed so that the upstream inert gas pressure is high and the downstream inert gas pressure is low. can do.

  Further, the gas introduction port is a first gas introduction port, and an inert gas having a gas amount smaller than the gas amount introduced through the first gas introduction port is provided downstream of the first gas introduction port. It is preferable that a second gas introduction port to be introduced into the film formation chamber is provided. Thus, by providing the auxiliary second gas inlet on the downstream side of the first inlet, the pressure of the inert gas downstream in the substrate transport direction can be corrected.

  In addition, it is preferable that a gas discharge port for discharging the gas in the film formation chamber to the outside is provided on the downstream side of the gas introduction port in the substrate transfer direction. Thus, the gas in the film forming chamber is discharged by the gas discharge port provided on the downstream side in the substrate transport direction, so that the pressure of the inert gas on the upstream side is high and the pressure of the inert gas on the downstream side is low. A pressure gradient can be formed as follows.

  Further, the pressure gradient forming means may be configured to form a pressure gradient by reducing the pressure of the inert gas in the film forming chamber as time elapses. As a result, the pressure gradient that lowers the pressure in the film formation chamber from the first pressure state to the second pressure state in a state where the substrate is stationary without transporting the substrate as the film formation time elapses. Can be formed. As a result, it is possible to reduce the length of the film forming chamber and to reduce the size of the film forming apparatus, as compared with the case where a pressure gradient is formed from the upstream side to the downstream side in the transfer direction with the transfer unit. it can. Further, one gas inlet connected to the film formation chamber can be provided. Thereby, the mechanism for introducing gas can be simplified.

  Further, it is preferable that the pressure gradient forming means gradually decreases the pressure of the inert gas from the start of film formation. Thereby, a density gradient region in which the density gradually increases from the surface of the substrate can be formed as the molybdenum layer.

  In addition, a method for manufacturing a film formation substrate according to the present invention is a method for manufacturing a film formation substrate in which a molybdenum layer is formed on a substrate, in which a film formation material for forming a molybdenum layer is provided. A film forming step for forming a molybdenum layer on the substrate in the chamber, an inert gas is introduced into the film forming chamber, and the pressure of the inert gas in the film forming chamber is changed from the first pressure state to the first pressure state. A pressure gradient forming step capable of forming a pressure gradient to be lowered to a second pressure state lower than the pressure state, wherein the film forming step is performed in an atmosphere in which the pressure of the inert gas decreases along the pressure gradient. The film is formed in the second pressure state after being formed in the first pressure state.

  In such a method for manufacturing a film formation substrate, an inert gas is introduced into the film formation chamber to generate a pressure gradient that lowers the first pressure state to a second pressure state lower than the first pressure state. . The pressure gradient may be a pressure gradient according to the position or a pressure gradient according to the passage of time. By forming a molybdenum layer in a film formation chamber in which such a pressure gradient has occurred, a molybdenum layer having a metal density gradient formed from the substrate side to the surface side can be formed. This metal density gradient increases with increasing distance from the substrate side. In other words, in the film thickness direction of the molybdenum layer, a density gradient is formed so that the density decreases as it approaches the substrate side from the surface side. When the LASER scribe method is applied to the molybdenum layer having such a density gradient, the molybdenum layer is preferably removed. Since the density of the molybdenum layer decreases as the depth increases from the surface side, the molybdenum layer can be suitably removed even when the LASER intensity is attenuated according to the depth, and good pattern formation is realized.

  The film formation substrate manufacturing method further includes a substrate transfer step of transferring the substrate in the film formation chamber, and the pressure gradient forming step sets the upstream side in the substrate transfer direction to the first pressure state and the downstream side in the substrate transfer direction. It is preferable to form a pressure gradient with the second pressure state.

  In such a method for manufacturing a deposition substrate, an inert gas is introduced into the deposition chamber, and the pressure of the inert gas on the upstream side in the substrate transport direction is higher than the pressure of the inert gas on the downstream side in the substrate transport direction. The pressure gradient is formed so as to be higher. This pressure gradient is formed such that the upstream inert gas pressure is high and the downstream inert gas pressure is low. By forming a molybdenum layer in a film formation chamber in which such a pressure gradient has occurred, a molybdenum layer having a metal density gradient formed from the substrate side to the surface side can be formed. This metal density gradient increases with increasing distance from the substrate side. In other words, in the film thickness direction of the molybdenum layer, a density gradient is formed so that the density decreases as it approaches the substrate side from the surface side. When the LASER scribe method is applied to the molybdenum layer having such a density gradient, the molybdenum layer is preferably removed. Since the density of the molybdenum layer decreases as the depth increases from the surface side, the molybdenum layer can be suitably removed even when the LASER intensity is attenuated according to the depth, and good pattern formation is realized.

  In the film forming chamber, a plurality of film forming materials are arranged in the substrate transfer direction, and the pressure gradient forming process introduces an inert gas upstream of the central film forming material in the substrate transfer direction. It is preferable to do. Thus, when a plurality of film forming materials are provided, an inert gas is introduced upstream of the center in the substrate transport direction of the plurality of film forming materials, so that the inert gas on the upstream side The pressure gradient can be formed so that the pressure is high and the pressure of the inert gas downstream is low.

  In the pressure gradient forming step, it is preferable to introduce an inert gas upstream of the film forming material in the film transport direction in the film forming chamber. In this way, by introducing an inert gas upstream of the film forming material, a pressure gradient is formed so that the upstream inert gas pressure is high and the downstream inert gas pressure is low. can do.

  Further, the pressure gradient forming step may introduce an inert gas at a plurality of different positions in the substrate transport direction, and introduce an inert gas having a smaller gas amount at the downstream introduction position than at the upstream introduction position. preferable. Accordingly, the pressure of the downstream inert gas can be corrected by introducing the inert gas supplementarily at the downstream introduction position.

  In the pressure gradient forming step, it is preferable to discharge the gas in the film forming chamber to the outside from the downstream side in the substrate transfer direction. As a result, by discharging the gas in the film forming chamber on the downstream side in the substrate transfer direction, a pressure gradient is formed so that the pressure of the inert gas on the upstream side is high and the pressure of the inert gas on the downstream side is low. can do.

  Further, the pressure gradient forming step may be configured such that the pressure gradient is formed by reducing the pressure of the inert gas in the film forming chamber as time elapses. As a result, the pressure gradient that lowers the pressure in the film formation chamber from the first pressure state to the second pressure state in a state where the substrate is stationary without transporting the substrate as the film formation time elapses. Can be formed. As a result, the length of the film forming chamber can be shortened and the film forming apparatus can be downsized as compared with the case where a pressure gradient is formed from the upstream side to the downstream side in the transfer direction with the transfer step. it can. Further, one gas inlet connected to the film formation chamber can be provided. Thereby, the mechanism for introducing gas can be simplified.

  In the pressure gradient forming step, it is preferable to gradually reduce the pressure of the inert gas from the start of film formation. As a result, a density gradient region in which the density gradually decreases from the surface of the substrate can be formed as the molybdenum layer.

  The film formation substrate according to the present invention includes a substrate and a molybdenum layer formed on the substrate, and the molybdenum layer has a density gradient region in which the density decreases as the substrate approaches the substrate in the film thickness direction. It is a feature.

  In such a film formation substrate, in the film thickness direction of the molybdenum layer, a density gradient is formed so that the density decreases as it approaches the substrate side from the surface side. When the LASER scribe method is applied to the molybdenum layer having such a density gradient, the molybdenum layer is preferably removed. Since the density of the molybdenum layer decreases as the depth increases from the surface side, the molybdenum layer can be suitably removed even when the LASER intensity is attenuated according to the depth, and good pattern formation is realized.

  ADVANTAGE OF THE INVENTION According to this invention, when patterning using a LASER scribe method, the film-forming apparatus which can form the molybdenum layer which can be removed suitably can be provided.

  Furthermore, according to the present invention, it is possible to provide a method for manufacturing a deposition substrate capable of forming a molybdenum layer that can be suitably removed when patterning is performed using the LASER scribe method.

  In addition, according to the present invention, it is possible to provide a deposition substrate on which a molybdenum layer that can be suitably removed when patterning is performed using the LASER scribe method.

It is sectional drawing of the photovoltaic cell which concerns on embodiment of this invention. 1 is a schematic cross-sectional configuration diagram illustrating a film forming apparatus according to an embodiment of the present invention. It is a schematic block diagram which shows the pressure gradient formation means which concerns on embodiment of this invention. It is a graph which shows the relationship between the position of the board | substrate conveyance direction in a film-forming chamber, and the pressure of argon gas. It is a graph which shows the relationship between the film thickness and film density of the film-forming board | substrate which concerns on embodiment of this invention. It is the SEM photograph which image | photographed the film-forming board | substrate after applying a LASER scribe method. It is a graph which shows the relationship between the film thickness and film density of the film-forming board | substrate which concerns on the conventional embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a film forming apparatus, a film forming substrate manufacturing method, and a film forming substrate according to the present invention will be described with reference to the drawings. The film formation substrate of the present invention is used, for example, as a back electrode of a solar battery cell. FIG. 1 is a cross-sectional view of a solar battery cell according to an embodiment of the present invention. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

(Deposition substrate)
A solar battery cell 1 shown in FIG. 1 is a CIGS solar battery, and a back electrode layer 3, a CIGS layer 4, a buffer layer 5, and a transparent electrode layer 6 are sequentially laminated on a glass substrate 2.

  The glass substrate 2 is soda glass containing sodium (Na). The CIGS layer 4 is a power generation layer made of a semiconductor containing copper (Cu), indium (In), gallium (Ga), and selenium (Se).

  The back electrode layer 3 includes an adhesion layer 3a formed on the surface of the glass substrate 2, and a molybdenum layer 3b formed on the surface of the adhesion layer 3a.

The adhesion layer 3a is formed in a first atmosphere containing oxygen and has molybdenum oxide. A small amount of oxygen is added to the adhesion layer 3a. The film thickness of the adhesion layer 3a is, for example, about 10 nm to 100 nm. The sheet resistance value of the adhesion layer 3a is, for example, about 10Ω / □ to 100Ω / □. The gas contained in the first atmosphere may be a gas other than oxygen, and carbon monoxide (CO), carbon dioxide (CO ₂ ), steam (H ₂ O), nitrogen trioxide (NO ₃ ), dioxide A gas that acts as an oxidizing gas in plasma such as nitrogen (NO ₂ ), nitrous oxide (N ₂ O), and ozone (O ₃ ) may be used.

  The molybdenum layer 3b is a molybdenum layer formed in a second atmosphere having a lower oxygen content than the first atmosphere. The film thickness of the molybdenum layer 3b is, for example, about 400 nm to 900 nm. The sheet resistance value of the molybdenum layer 3b is, for example, about 0.2Ω / □ to 0.5Ω / □.

  The adhesion layer 3a functions as an adhesion layer disposed between the glass substrate 2 and the molybdenum layer (molybdenum main layer) 3b. The molybdenum layer 3b is formed so as to be thicker than the adhesion layer 3a. Further, the sheet resistance value of the molybdenum layer 3b is formed to be lower than the sheet resistance value of the first molybdenum 3a.

  Here, the molybdenum layer 3b of the film formation substrate 1 is configured to have a density gradient region in which the density decreases as the glass substrate 2 is approached in the film thickness direction. In addition, although the film-forming substrate 1 of this embodiment is the structure provided with the contact | adherence layer 3a used as an contact | adherence layer, the structure which has a single molybdenum layer and has a density gradient area | region in the said molybdenum layer may be sufficient.

  The film formation substrate 1 may have a structure having a density gradient region in the molybdenum layer, or may have a structure having a uniform density in the film thickness direction. In general, when crystal grains and grain boundaries of a metal film (molybdenum layer) are compared, the density of the crystal grains is higher, and the density of the molybdenum layer and the size of the crystal grains have a one-to-one correlation. That is, the higher the density of the molybdenum layer, the larger the crystal grains. Thereby, the cross-sectional SEM (scanning electron microscope) photograph of the molybdenum layer is observed, and the change in the density of the molybdenum layer (density gradient region) is confirmed by checking the size of the crystal grains in the film thickness direction (ratio of the cross-sectional area). Presence or absence).

FIG. 5 is a graph showing the relationship between the film thickness and the film density of the film formation substrate according to the embodiment of the present invention. In FIG. 5, the horizontal axis indicates the film thickness of the molybdenum layer, and the vertical axis indicates the film density. Position F ₁ in the film thickness direction is the most of the glass substrate 2 side position of the molybdenum layer 3b, the position F ₂ in the thickness direction is the position of the most front side of the molybdenum layer 3b (CIGS layer 4 side). As shown in FIG. 5, in the molybdenum layer 3 b of the film formation substrate 1, a density gradient is formed in which the density decreases in the film thickness direction as it approaches the glass substrate 2.

(Deposition system)
Next, a film forming apparatus 10 for forming a molybdenum layer on the glass substrate 2 will be described with reference to FIG. A film forming apparatus 10 shown in FIG. 2 is an apparatus for forming a film by a sputtering method. Plasma is generated in a dilute argon atmosphere in a vacuum, and positive ions in the plasma are applied to a film forming material (Mo target) 21. By colliding, metal atoms are ejected and deposited on the substrate to form a film.

  The film forming apparatus 10 includes first and second film forming chambers (vacuum chambers) 11A and 11B in which a film forming process is performed, and a substrate preparation chamber (exhaust chamber) 12A is connected to the inlet side of the first film forming chamber 11A. In addition, a substrate take-out chamber (vent chamber) 12B is connected to the outlet side of the second film formation chamber 11B. A gas separation chamber 12C is connected between the first film formation chamber 11A and the second film formation chamber 11B. The inlet side of the gas separation chamber 12C is connected to the outlet side of the first film forming chamber 11A, and the inlet side of the second film forming chamber 11B is connected to the outlet side of the gas separation chamber 12C.

  The substrate preparation chamber 12A is a chamber for taking a substrate under atmospheric pressure into the apparatus and evacuating the chamber. The substrate take-out chamber 12B is a chamber for taking out a film formation substrate in a vacuum (a glass substrate on which a molybdenum layer is formed) into an atmospheric pressure environment. The gas separation chamber 12C is a chamber for changing the partial pressure ratio between oxygen gas and argon gas by gas replacement.

  Hereinafter, the substrate preparation chamber 12A, the first film formation chamber 11A, the gas separation chamber 12C, the second film formation chamber 11B, and the substrate take-out chamber 12B may be referred to as chambers 11 and 12, respectively. These chambers 11 and 12 are constituted by vacuum containers, and gate valves GV are provided at the entrances and exits of the chambers 11 and 12. The gate valve GV is a valve having a relatively large valve body for separating a vacuum environment and an atmospheric pressure environment. When the pressures on both sides of the gate valve GV are equal, the gate valve GV is opened to allow the adjacent chambers 11 and 12 to communicate with each other and allow the substrate 2 to pass.

  In each chamber 11, 12, a substrate transport roller 14 (substrate transport means) for transporting the substrate 2 is installed, and a heater 15 for heating the substrate 2 is installed. The heater 15 heats the substrate so that the substrate temperature is constant, for example, in the range of 70 ° C to 350 ° C.

  Furthermore, a rotary pump 16 is connected to the substrate preparation chamber 12A and the substrate take-out chamber 12B, and a TMP (turbo molecular pump) 17 is connected to the chambers 11 and 12. The rotary pump 16 is a pump used for exhausting in a viscous flow region from atmospheric pressure to 1 Pa, and the TMP 17 is a pump used for exhausting in a molecular flow region of 1 Pa or less.

  The film forming apparatus 10 has a sputtering cathode (holding unit) (not shown) for holding a sputtering target in the first and second film forming chambers 11A and 11B. The Mo target 21 which is a sputtering target is disposed on the first and second film forming chambers 11A and 11B. In the second film formation chamber 11 </ b> B, a plurality of Mo targets 21 are arranged along the transport direction of the substrate 2. The Mo target 21 is electrically connected to the DC power source 23. The DC power source 23 is a power source that supplies DC power.

  Here, the first film formation chamber 11A is a film formation chamber in which the adhesion layer 3a is formed on the surface of the glass substrate 2 in a first atmosphere containing a predetermined amount of oxygen. The second film formation chamber 11B is a film formation chamber in which the molybdenum layer 3b is formed on the surface of the adhesion layer 3a in a second atmosphere having a lower oxygen content than the first atmosphere.

  Then, the film forming apparatus 10 uses the first film forming chamber 11A as a first atmosphere containing a predetermined amount of oxygen, and the second film forming chamber 11B has a higher oxygen content than the first atmosphere. Gas concentration adjusting devices (oxygen concentration control units) 30A and 30B for providing a low second atmosphere are provided.

  The gas concentration adjusting device 30A supplies gas into the first film forming chamber 11A and adjusts the oxygen concentration in the first film forming chamber 11A. The gas concentration adjusting device 30A includes a mass flow controller 31 for adjusting the amount of oxygen gas introduced into the first film forming chamber 11A, a mass flow controller 32 for adjusting the amount of argon gas introduced into the first film forming chamber 11A, and a first component. A gas supply path 33 connected to the film chamber 11A for introducing oxygen gas and / or argon gas, an oxygen concentration meter 34 for detecting the oxygen concentration in the first film formation chamber 11A, and the oxygen concentration in the first film formation chamber 11A A control unit 35 for controlling the mass flow controller 31 is provided.

  The gas concentration adjusting device (gas concentration adjusting device) 30B supplies gas into the second film forming chamber 11B and adjusts the oxygen concentration in the second film forming chamber 11B. The gas concentration adjusting device 30B includes a mass flow controller 31 that adjusts the amount of oxygen gas introduced into the second film forming chamber 11B, a mass flow controller 32 that adjusts the amount of argon gas introduced into the second film forming chamber 11B, and a second component. A gas supply path 33 connected to the film chamber 11B for introducing oxygen gas and / or argon gas, an oxygen concentration meter 34 for detecting the oxygen concentration in the second film formation chamber 11B, and an oxygen concentration in the second film formation chamber 11B A control unit 35 for controlling the mass flow controller 31 is provided.

  The gas concentration adjusting device 30C supplies oxygen gas and / or argon gas into the gas separation chamber 12C and adjusts the oxygen concentration according to the state of the gate valve GV adjacent to the gas separation chamber 12C. That is, when the gate valve GV on the first film formation chamber 11A side is open, the oxygen concentration is adjusted to be the same as that in the first film formation chamber 11A, and when the gate valve GV on the second film formation chamber 11B side is open. Is adjusted to the same oxygen concentration as in the second film formation chamber 11B. The gate valve GV on the first film formation chamber 11A side and the gate valve GV on the second film formation chamber 11B side are controlled so as not to open simultaneously.

  An oxygen cylinder for supplying oxygen gas is connected to the mass flow controller 31 for adjusting the oxygen gas introduction amount, and an argon gas cylinder for supplying argon gas is connected to the mass flow controller 32 for adjusting the argon gas introduction amount. The oxygen gas and the argon gas whose flow rates are adjusted by the mass flow controllers 31 and 32 pass through the gas supply path 33 and are introduced into the first film formation chamber 11A and the second film formation chamber 11B, and the film formation chambers 11A and 11B. The oxygen partial pressure inside is kept constant. As the flow rate regulator for adjusting the oxygen gas introduction amount and the argon gas introduction amount, a thermal valve type, electromagnetic valve type, or piezo valve type flow rate regulator can be used.

  Further, the control unit 35 of the gas concentration adjusting devices 30A and 30B controls the mass flow controllers 31 and 32 based on the oxygen concentrations in the first film forming chamber 11A and the second film forming chamber 11B detected by the oxygen concentration meter 34. Can be controlled. For example, the control unit 35 adjusts the oxygen concentration in the film forming chamber 11 by controlling the oxygen gas introduction amount while keeping the introduction amount of argon gas constant. For example, the oxygen partial pressure in the first film formation chamber 11A is preferably controlled to about 0.003 Pa to 0.05 Pa, and the oxygen partial pressure in the second film formation chamber 11B is about 0 to 0.002 Pa. It is preferable to be controlled.

(Pressure gradient forming means)
The film forming apparatus 10 according to the embodiment of the present invention introduces an argon gas (inert gas) into the second film forming chamber 11B for forming the molybdenum layer 3b, and the substrate in the second film forming chamber 11B. Pressure gradient forming means is provided for forming a pressure gradient such that the pressure of the argon gas upstream in the transport direction is higher than the pressure of the argon gas downstream in the substrate transport direction. The pressure gradient forming unit is configured to be able to form a pressure gradient that lowers the pressure of the argon gas in the second film forming chamber 11B from the first pressure state to the second pressure state.

  The gas concentration adjusting device 30B of the present embodiment functions as pressure gradient forming means. FIG. 3 is a schematic view showing pressure gradient forming means according to the embodiment of the present invention. The pressure gradient forming means includes gas introducing portions 41A and 41B for introducing argon gas into the second film forming chamber 11B, and TMPs 17A and 17B.

  As shown in FIG. 3, for example, three Mo targets 21 </ b> A to 21 </ b> C are arranged along the substrate transport direction D in the second film formation chamber 11 </ b> B. The pressure gradient forming means includes, as an argon gas introduction portion, a first gas introduction portion (gas introduction port) 41A provided on the upstream side of the most upstream Mo target 21 in the substrate transport direction D, and the first gas introduction portion 41A. And a second gas introduction part 41B provided on the downstream side of the gas introduction part 41A.

  The first gas introduction part 41A and the second gas introduction part 41B have, for example, a cylindrical shape, and are arranged in a direction in which the longitudinal direction intersects the substrate transport direction D. A plurality of inlets for introducing argon gas into the room are formed on the peripheral surface of the cylindrical gas inlet. The first gas introduction part 41A and the second gas introduction part 41B are arranged, for example, above the position where the substrate is transferred (on the Mo target side than the substrate) in the vertical direction.

  The first gas introduction part 41A functions as a main gas introduction part, and the supply flow rate of argon gas in the first gas introduction part 41A is, for example, about 500 sccm. The second gas introduction unit 41B introduces a gas amount smaller than the gas amount introduced by the first gas introduction unit 41A, and the supply amount of the argon gas of the second gas introduction unit 41B is, for example, About 50 sccm.

  The first gas introduction part 41A may be provided on the upstream side of the central Mo target 21B in the substrate transport direction D. Further, the first gas introduction part 41 </ b> A may be provided in the upstream side of the intermediate position between the Mo target 21 on the most upstream side and the Mo target 21 on the most downstream side in the substrate transport direction D. Moreover, it is good also as a pressure gradient formation means which is not provided with the 2nd gas introduction part 41B.

  In addition, a gas discharge part (gas discharge port) for discharging the gas in the second film formation chamber 11B to the outside is provided in the substrate transport direction D on the downstream side of the first gas introduction part 41A. The pressure gradient forming means of the present embodiment includes a TMP 17A disposed on the upstream side and a TMP 17B disposed on the downstream side as gas discharge portions. The TMP 17A discharges gas from the discharge port on the upstream side of the first gas introduction part 41A, and the TMP 17B discharges gas from the discharge port on the downstream side of the Mo target 21C on the most downstream side. By adjusting the amount of exhaust gas by the TMPs 17A and 17B, the pressure gradient in the substrate transport direction D in the room can be adjusted.

(Operation of film forming apparatus and manufacturing method of film forming substrate)
Next, the operation of the film forming apparatus 10 and the method for manufacturing the film forming substrate will be described. The method for manufacturing a film formation substrate according to the present embodiment is a method for manufacturing a film formation substrate in which molybdenum is formed on a glass substrate 2, in a first atmosphere containing a predetermined amount of oxygen. In the first film formation step of forming the adhesion layer 3a on the surface of the substrate 2 and the second atmosphere having a lower oxygen content than the first atmosphere, the molybdenum layer 3b is formed on the surface of the adhesion layer 3a. And a second film forming step. The first film forming process is performed in the first film forming chamber 11A of the film forming apparatus 10, and the second film forming process is performed in the second film forming chamber 11B of the film forming apparatus 10.

First, as a pretreatment for the first film formation process and the second film formation process, the rotary film 16 and the TMP 17 are used to evacuate the first film formation chamber 11A and the second film formation chamber 11B to make a vacuum state. The pressure in the first film formation chamber 11A and the second film formation chamber 11B is preferably, for example, 5 × 10 ⁻⁴ Pa or less.

Next, the heaters 15 are turned on, and the set values in the heaters 15 are stabilized so that the temperature of the substrate 2 introduced into the chambers 11 to 13 is constant within a range of 70 ° C. to 350 ° C. . When the temperature of the heater 15 rises from a normal temperature to a set value (for example, 200 ° C.), gas such as H ₂ O and CO ₂ adhering to the heater 15 itself and the vacuum chambers 11 and 12 is desorbed, and The pressure of 12 rises temporarily.

After confirming that the pressure in the first film formation chamber 11A is a desired vacuum pressure (5 × 10 ⁻⁴ Pa or less), the control unit 35 of the gas concentration adjusting device 30A drives the mass flow controllers 31 and 32. Then, supply of oxygen gas and argon gas into the first film formation chamber 11A is started. The mass flow controllers 31 and 32 maintain the pressure in the first film forming chamber 11A at an arbitrary value within the range of 0.1 Pa to 1 Pa. In the first film formation step, the supply amounts of oxygen gas and argon gas are adjusted so that the oxygen content is 0.3% to 5.0%.

After confirming that the pressure in the second film forming chamber 11B is a desired vacuum pressure (5 × 10 ⁻⁴ Pa or less), the control unit 35 of the gas concentration adjusting device 30B drives the mass flow controllers 31 and 32. Then, supply of oxygen gas and / or argon gas into the second film forming chamber 11B is started. The mass flow controllers 31 and 32 maintain the pressure in the second film forming chamber 11B at an arbitrary value within the range of 0.1 Pa to 1 Pa. In the second film forming step, the supply amount of oxygen gas and / or argon gas is adjusted so that the oxygen content is 0.0% to 0.2%.

  Thereafter, the DC power source 23 is turned on to generate plasma in the film forming chamber 11.

When plasma discharge in the first film formation chamber 11A is started, sputtering of the Mo target 21 starts. At this time, DC power supply 23, the power density for the Mo target 21 ^is controlled to maintain an arbitrary value within the range of ^{1W / cm 2 ~5W / cm 2} .

When the plasma discharge in the second film forming chamber 11B is started, the sputtering of the Mo target 21 starts. At this time, DC power supply 23, the power density for the Mo target 21 ^is controlled to maintain an arbitrary value within the range of ^{5W / cm 2 ~30W / cm 2} .

  Here, the control unit 35 of the gas concentration adjusting devices 30A and 30B controls the mass flow controller 31 so that the oxygen gas introduction flow rate is, for example, 1/1000 to 1/10 of the argon gas introduction flow rate. Control to maintain any value within range.

  The glass substrate 2 which is a film formation substrate is introduced into the substrate preparation chamber 12A. When the glass substrate 2 is introduced into the substrate preparation chamber 12A, the rotary pump 16 and the TMP 17 are evacuated, and the inside of the substrate preparation chamber 12A is in a vacuum state. When the inside of the substrate preparation chamber 12A is in a vacuum state, the gate valve GV disposed between the substrate preparation chamber 12A and the first film formation chamber 11A is opened, and the substrate preparation chamber 12A and the first film formation chamber 11A communicate with each other. The glass substrate 2 is introduced into the first film forming chamber 11A.

  In the first film forming chamber 11A, the substrate transport speed by the substrate transport roller 14 is controlled to a constant value, and the film thickness of the adhesion layer 3a formed on the glass substrate 2 is controlled. In the first film formation chamber 11 </ b> A, a space in which molybdenum is sputtered is formed immediately below the Mo target 21. Then, the adhesion layer 3 a is formed on the glass substrate 2 by allowing the glass substrate 2 to pass through the sputtering space. In the first film forming chamber 11A in which the first film forming process is performed, it is preferable that the transport speed is controlled so that the average value of the film thickness of the adhesion layer 3a is, for example, 10 nm or more.

  The glass substrate 2 after completion of film formation in the first film formation step is transferred to the gas separation chamber 12C. In the gas separation chamber 12C, the partial pressure ratio between oxygen gas and argon gas is changed by gas replacement, and the glass substrate 2 is transferred into the second film forming chamber 11B.

  In the second film forming chamber 11B, the substrate transfer speed by the substrate transfer roller 14 is controlled to a constant value (substrate transfer step), and the film thickness of the molybdenum layer 3b formed on the glass substrate 2 is controlled. In the second film forming chamber 11 </ b> B, a space in which molybdenum is sputtered is formed immediately below the Mo target 21. Then, the molybdenum layer 3 b is formed on the glass substrate 2 by allowing the glass substrate 2 to pass through the sputtering space. In the second film forming chamber 11B in which the second film forming process is performed, it is preferable that the transport speed is controlled so that the average value of the film thickness of the molybdenum layer 3b is, for example, 400 nm or more.

  The glass substrate 2 after completion of film formation in the second film formation step is transferred to the substrate take-out chamber 12B. In the substrate take-out chamber 12B, air is introduced into the chamber, and the glass substrate 2 is transferred to the outside of the substrate take-out chamber 12B when the pressure in the chamber changes from vacuum to atmospheric pressure. In order to prepare for the introduction of the next glass substrate 2 after the completion of film formation, the substrate extraction chamber 12B after the glass substrate 2 is extracted is evacuated by the rotary pump 16 and the TMP 17 to be in a vacuum state. The The film forming apparatus 10 may have a configuration in which a sequence is incorporated so that various steps in the method for manufacturing a film forming substrate automatically proceed sequentially.

(Pressure gradient forming process)
The film formation substrate manufacturing method according to the present embodiment introduces argon gas into the second film formation chamber 11B, and the pressure of the argon gas upstream in the substrate transport direction D within the second film formation chamber 11B. A pressure gradient forming step of forming a pressure gradient so that P ₂ (see FIG. 4) becomes higher than the pressure P ₃ of the argon gas downstream in the substrate transport direction D is provided. In this pressure gradient forming step, argon gas is introduced into the chamber upstream of the most upstream Mo target 21A to form a pressure gradient. In the pressure gradient forming step, the pressure of the argon gas in the second film forming chamber 11B is changed from the first pressure state (pressure P ₂ ) to the second pressure state (pressure P ₃ ) lower than the first pressure state. Create a pressure gradient that reduces to

  In the pressure gradient forming step, argon gas may be introduced at other positions to form a pressure gradient. For example, argon gas may be introduced upstream of the central Mo target 21B in the substrate transport direction D. Moreover, you may introduce | transduce argon gas upstream from the intermediate position of the Mo target of the most upstream side and Mo target of the most downstream side.

  In the pressure gradient forming step, argon gas is introduced at a plurality of different positions in the substrate transport direction D, and an argon gas having a smaller gas amount is introduced at the downstream introduction position than at the upstream introduction position. The argon gas introduction position may be one or a plurality of positions in the substrate transport direction D. When there are a plurality of argon gas introduction positions, the main introduction position is provided on the upstream side. In the pressure gradient forming step, the gas in the second film formation chamber 11B is discharged to the outside from the downstream side of the argon gas introduction position.

FIG. 4 is a graph showing the relationship between the position in the substrate transport direction in the film forming chamber and the pressure of the argon gas. In FIG. 4, the horizontal axis indicates the position in the transport direction in the second film formation chamber 11B, and the vertical axis indicates the argon gas pressure in the second film formation chamber 11B. Position D ₁ is the most upstream position of the second film forming chamber 11B, the position D ₂ is the position of the first gas inlet, the position D ₃ is the most downstream position. As shown in FIG. 4, the pressure of argon gas toward position _{D 2} from the position _{D 1} is increased from the pressure _{P 1} to a pressure _{P 2,} the pressure of argon gas toward position _{D 3} from the position _{D 2,} from the pressure _{P 2} as lowered to the pressure P _3, the pressure gradient is formed.

  FIG. 6 is an SEM photograph of the film formation substrate after the LASER scribe method is applied. FIG. 6A is an SEM photograph of the film formation substrate according to the embodiment of the present invention, and FIG. 6B is an SEM photograph of the film formation substrate of the conventional example. As shown in FIG. 6A, it can be seen that when the LASER scribing method is applied to the film formation substrate of the present embodiment, the molybdenum layer 3b is suitably removed without generating a residue.

  As described above, in the film forming apparatus and the film forming substrate manufacturing method of the present embodiment, the argon gas pressure gradient is generated in the film forming chamber from the upstream side to the downstream side in the substrate transport direction. This pressure gradient is formed so that the pressure of the upstream argon gas is high and the pressure of the downstream argon gas is low. By forming a molybdenum layer in a film formation chamber in which such a pressure gradient has occurred, a molybdenum layer having a metal density gradient formed from the substrate side to the surface side can be formed. This metal density gradient increases with increasing distance from the substrate side. In other words, in the film thickness direction of the molybdenum layer, the density gradient is formed so that the density decreases as it approaches the substrate side from the surface side.

  In addition, since the introduction port for introducing argon gas into the film formation chamber is provided upstream of the film formation material, a suitable pressure gradient can be formed in the substrate transport direction.

  In the film formation substrate of this embodiment, the density gradient is formed so that the density of the molybdenum layer decreases as the depth increases from the surface side. Thereby, when the LASER scribe method is applied to the film formation substrate, the molybdenum layer can be suitably removed even if the LASER intensity is attenuated according to the depth in the film thickness direction. As a result, good pattern formation is realized.

  In the film formation substrate of this embodiment, the adhesion layer 3a containing oxygen is formed on the surface of the glass substrate 2, and the glass substrate 2 and the adhesion layer 3a are firmly adhered to each other. A molybdenum layer 3b having a lower oxygen content than the adhesion layer 3a is formed on the surface of the adhesion layer 3a, and the adhesion layer 3a and the molybdenum layer 3b are firmly adhered to each other. That is, the molybdenum layer 3b is formed on the glass substrate 2 through the adhesion layer 3a, and the adhesion between the molybdenum layer 3b and the glass substrate 2 is improved. As a result, it is possible to suppress a decrease in yield when manufacturing solar cells. In addition, the quality of the solar battery cell can be improved.

  Here, the sheet resistance value of the molybdenum layer 3b is preferably lower than the sheet resistance value of the adhesion layer 3a, and molybdenum having a sheet resistance value lower than the sheet resistance value of the adhesion layer 3a is formed on the surface of the adhesion layer 3a. By forming the layer 3b, it is possible to improve the adhesion while reducing the resistance and improving the function as an electrode film.

  Further, the molybdenum layer 3b is preferably thicker than the adhesion layer 3a, and a molybdenum layer having a low sheet resistance value can be formed by forming the molybdenum layer 3b having a thickness larger than that of the adhesion layer 3a. Therefore, in the solar cell 1 provided with the film formation substrate, low resistance and high conversion rate can be realized. Further, by making the adhesion layer 3a having a high sheet resistance thinner than the molybdenum layer 3b, it is possible to suppress an increase in the resistance value of the entire deposition substrate while enhancing the adhesion between the glass substrate 2 and the adhesion layer 3a.

  Further, the film forming apparatus 10 of the present embodiment includes a first film forming chamber 11A for forming the adhesion layer 3a on the surface of the glass substrate 2, and the first film forming chamber 11A contains a first oxygen containing oxygen. As an atmosphere, an adhesion layer 3 a can be formed on the glass substrate 2. Thereby, the glass substrate 2 and the contact | adherence layer 3a can be firmly stuck. Further, the film forming apparatus 10 includes a second film forming chamber 11B for forming the molybdenum layer 3b on the surface of the adhesion layer 3a, and the oxygen content in the second film forming chamber 11B is higher than that in the first atmosphere. As a second atmosphere having a low temperature, the molybdenum layer 3b can be formed on the surface of the adhesion layer 3a. Thereby, the adhesion layer 3a and the molybdenum layer 3b can be firmly adhered. That is, the molybdenum layer 3b is formed on the glass substrate 2 through the adhesion layer 3a, and the adhesion between the molybdenum layer 3b and the glass substrate 2 is improved. Note that a film forming apparatus including a film forming chamber serving as both the first film forming chamber 11A and the second film forming chamber 11B may be used.

  Moreover, in the manufacturing method of the film-forming board | substrate of this embodiment, the contact | adherence layer 3a is formed into a film on the surface of the glass substrate 2 in the 1st atmosphere containing oxygen, and the contact | adherence layer 3a adheres to the glass substrate 2 firmly. To do. Then, a molybdenum layer 3b is formed on the surface of the adhesion layer 3a, and the molybdenum layer 3b is firmly adhered to the adhesion layer 3b. That is, the molybdenum layer 3b is formed on the glass substrate via the adhesion layer 3a, and the adhesion force between the molybdenum layer 3b and the glass substrate 2 is improved.

  When the film formation substrate of this embodiment is used for a solar battery cell, the molybdenum layers 3a and 3b are peeled off even when exposed to high temperatures (for example, 600 ° C.) in other steps after the molybdenum film formation step. Can be prevented. In addition, the molybdenum layers 3a and 3b can be prevented from being peeled off when LASER scribing is performed on the deposition substrate. Therefore, it is possible to improve the adhesion of the molybdenum layer.

  In the film formation substrate of this embodiment, since the adhesion of the molybdenum layer is improved, the sodium content in the glass substrate 2 suitably passes through the molybdenum layer and reaches the CIGS layer 4 that adheres to the molybdenum layer. The power generation efficiency in the CIGS layer 4 can be improved.

  As mentioned above, although this invention was concretely demonstrated based on the embodiment, this invention is not limited to the said embodiment. In the above-described embodiment, the film formation is performed by the sputtering method. However, for example, the physical vapor deposition method or the ion plating method may be applied, or the film formation may be performed by using other film formation methods.

  Moreover, in the said embodiment, although the film-forming board | substrate of this invention is applied to the CIGS type solar cell, even if it applies the film-forming board | substrate of this invention to other solar cells, such as a dye-sensitized type, for example. Good. Furthermore, you may apply the film-forming board | substrate of this invention to the board | substrate used for a touch panel, a liquid crystal display (liquid crystal display element), an organic EL element, etc.

  In the above embodiment, the pressure gradient that reduces the pressure of the inert gas in the film forming chamber 11B is formed in the longitudinal direction (substrate transport direction) of the film forming chamber 11B. The pressure gradient may be formed by lowering the pressure of the inert gas in the film formation chamber 11B with the passage of the film formation time while the substrate is stationary. Accordingly, it is not necessary to form a pressure gradient in the longitudinal direction of the film forming chamber 11B, so that the film forming chamber 11B can be shortened and the film forming apparatus 10 can be downsized.

  Moreover, when forming the pressure gradient which reduces the pressure of an inert gas according to progress of time, it is preferable to reduce the pressure of an inert gas gradually from the start of film-forming. Thereby, a density gradient region in which the density gradually increases from the surface of the substrate can be formed as the molybdenum layer.

  In addition, when forming a pressure gradient according to the film formation time, it is possible to form a pressure gradient using one gas introduction part, so that the number of gas introduction parts can be reduced, and inert gas can be reduced. A gas supply mechanism for supplying the film forming chamber 11B can be simplified.

  In addition, although the said embodiment demonstrated the case where a molybdenum layer was formed into a film on a glass substrate, the board | substrate with which a molybdenum layer is formed into a film is not limited to a glass substrate, Another board | substrate may be sufficient.

  Moreover, in the said embodiment, although the inert gas is argon gas, the structure which uses another inert gas may be sufficient.

  DESCRIPTION OF SYMBOLS 1 ... Solar cell, 2 ... Glass substrate, 3 ... Back electrode layer, 3a ... Adhesion layer, 3b ... Molybdenum layer, 10 ... Film-forming apparatus (sputtering apparatus), 11A ... 1st film-forming chamber, 11B ... 2nd composition Membrane chamber, 30A, 30B, 30C ... gas concentration adjusting device, 31, 32 ... mass flow controller, 35 ... control unit, 41A ... first gas introduction unit (introduction port), 41B ... second gas introduction unit (introduction port) ), D: substrate transport direction.

Claims (17)

A film forming apparatus for forming a molybdenum layer on a substrate,
A film forming material for forming the molybdenum layer is installed, and a film forming chamber for forming the molybdenum layer on the substrate;
A pressure gradient that introduces an inert gas into the film formation chamber and lowers the pressure of the inert gas in the film formation chamber from the first pressure state to a second pressure state lower than the first pressure state. A pressure gradient forming means capable of forming
With
The film formation chamber is formed in the second pressure state after being formed in the first pressure state in an atmosphere in which the pressure of the inert gas decreases along the pressure gradient. A film forming apparatus. A substrate transfer means for transferring the substrate in the film forming chamber;
The pressure gradient forming means forms the pressure gradient in which the upstream side in the substrate transport direction is the first pressure state and the downstream side in the substrate transport direction is the second pressure state. 2. The film forming apparatus according to 1. A plurality of the film forming materials are arranged in the substrate transport direction,
3. The film forming apparatus according to claim 2, wherein a gas introduction port for introducing an inert gas into the film forming chamber is provided upstream of the film forming material at the center in the substrate transport direction. .   The film forming apparatus according to claim 2, wherein a gas introduction port for introducing an inert gas into the film forming chamber is provided upstream of the film forming material.   The gas introduction port is a first gas introduction port, and an inert gas having a gas amount smaller than the gas amount introduced through the first gas introduction port is provided downstream of the first gas introduction port. The film forming apparatus according to claim 3, wherein a second gas introduction port for introducing the film into the film forming chamber is provided.   6. The gas discharge port according to claim 2, wherein a gas discharge port for discharging the gas in the film forming chamber to the outside is provided on the downstream side of the gas introduction port in the substrate transfer direction. Film forming equipment.   2. The film forming apparatus according to claim 1, wherein the pressure gradient forming unit forms the pressure gradient by reducing the pressure of the inert gas in the film forming chamber as time elapses.   The film forming apparatus according to claim 7, wherein the pressure gradient forming unit gradually reduces the pressure of the inert gas from the start of film formation. A method of manufacturing a film formation substrate in which a molybdenum layer is formed on a substrate,
A film forming step of forming the molybdenum layer on the substrate in a film forming chamber in which a film forming material for forming the molybdenum layer is installed;
A pressure gradient that introduces an inert gas into the film formation chamber and lowers the pressure of the inert gas in the film formation chamber from the first pressure state to a second pressure state lower than the first pressure state. A pressure gradient forming step capable of forming
With
The film-forming step is characterized in that the film is formed in the second pressure state after being formed in the first pressure state in an atmosphere in which the pressure of the inert gas decreases along the pressure gradient. A method for manufacturing a film formation substrate. A substrate transfer step of transferring the substrate in the film formation chamber;
10. The composition according to claim 9, wherein the pressure gradient forming step forms the pressure gradient in which the upstream side in the substrate transport direction is the first pressure state and the downstream side in the substrate transport direction is the second pressure state. Membrane substrate manufacturing method. In the film forming chamber, a plurality of film forming materials are arranged in the substrate transport direction,
11. The method for manufacturing a film formation substrate according to claim 10, wherein in the pressure gradient forming step, an inert gas is introduced upstream of the film formation material at the center in the substrate transfer direction.   12. The method of manufacturing a film formation substrate according to claim 11, wherein in the pressure gradient forming step, an inert gas is introduced into the film formation chamber upstream of the film formation material in the substrate transport direction.   The pressure gradient forming step introduces an inert gas at a plurality of different positions in the substrate transfer direction, and introduces an inert gas having a smaller gas amount at the downstream introduction position than at the upstream introduction position. 13. The method for producing a film-formed substrate according to claim 11 or 12, characterized in that:   The film formation substrate manufacturing according to any one of claims 10 to 13, wherein the pressure gradient forming step discharges the gas in the film formation chamber to the outside from the downstream side of the introduction position of the inert gas. Method.   The method for manufacturing a film formation substrate according to claim 9, wherein the pressure gradient formation step forms the pressure gradient by reducing the pressure of the inert gas in the film formation chamber as time elapses.   16. The method for manufacturing a film formation substrate according to claim 15, wherein the pressure gradient forming step gradually decreases the pressure of the inert gas from the start of film formation. A substrate,
A molybdenum layer formed on the substrate,
The film formation substrate characterized in that the molybdenum layer has a density gradient region whose density decreases in the film thickness direction as it approaches the substrate.