KR20140118697A

KR20140118697A - Film forming method

Info

Publication number: KR20140118697A
Application number: KR1020140002358A
Authority: KR
Inventors: 사토시 야마모토
Original assignee: 다이니폰 스크린 세이조우 가부시키가이샤
Priority date: 2013-03-28
Filing date: 2014-01-08
Publication date: 2014-10-08
Also published as: TW201437399A; JP2014189861A; CN104073769A

Abstract

Provided is a technology of forming a film having an excellent characteristic at a sufficient rate. Sputter voltage is applied to an aluminum target object to generate first plasma in a processing space. Simultaneously, high-frequency current is applied to an inductive coupling antenna having less than one winding number, thereby generating an inductive-coupling type of second plasma in the processing space. The aluminum target object is sputtered by supplying sputter gas and oxygen into the processing gas, and an aluminum oxide film is formed on a target object (9) through a reactive sputtering process. At least first plasma is generated in the processing space, and the aluminum target object is sputtered by supplying the sputter gas into the processing space, thereby forming an aluminum film on the target object (9). The target object (9) having one of the aluminum oxide film and the aluminum film is not exposed to the atmosphere, but the other film is laminated on one film formed on the target object (9).

Description

[0001] FILM FORMING METHOD [0002]

The present invention relates to a technique for forming a film on an object.

Conventionally, various techniques for forming a film on a film-adhered object exist. For example, Patent Document 1 describes a technique of forming a thin film of aluminum oxide (Al ₂ O ₃ ) (passivation film) on the back surface of a p-type silicon substrate by ALD (atomic layer deposition) .

Japanese Patent Application Laid-Open No. 2007-39088 Japanese Unexamined Patent Application Publication No. 2011-176283 Japanese Patent No. 4005912

The aluminum oxide film is promising as a back passivation film for a p-type silicon substrate of a solar cell, for example, because it has excellent electrical characteristics and sealing properties. Incidentally, the ALD method is not suitable for mass production because the film formation rate is extremely slow, and therefore an aluminum oxide film is produced by the ALD method.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of forming a film having excellent characteristics at a sufficient rate.

The first aspect is a film forming method for forming a film on an object by magnetron sputtering, comprising the steps of: a) generating a first plasma in a processing space by applying a sputtering voltage to an aluminum target, A second plasma of an inductively coupled type is generated in the processing space by causing a high frequency current to flow through the coupling antenna to supply sputter gas and oxygen to the processing space and sputtering the aluminum target to oxidize the object by reactive sputtering B) a step of supplying a sputtering gas into the processing space while generating at least the first plasma in the processing space before or after the step a); and b) And a step of forming an aluminum film on the object, Group without exposing the object film is formed of one of an aluminum film to the air, to form the laminated film and the other film on the one which is formed on the object.

The second aspect is the film forming method according to the first aspect, wherein the step b) is performed after the step a).

The third aspect is the film forming method according to the second aspect, wherein the step a) includes the steps of advancing the reactive sputtering while supplying a sputter gas and a first amount of oxygen to the processing space a1) , a2) advancing the reactive sputtering while supplying a sputter gas and a second amount of oxygen less than the first amount to the processing space, and after the a1) step, the a2) step is performed I do.

The fourth aspect is the film forming method according to any one of the first to third aspects, wherein: (c) the inner space is partitioned into a plurality of processing spaces, and a sputter source is disposed in each of the plurality of processing spaces And a step of transporting the object along the arrangement direction of the plurality of processing spaces in the chamber in which the processing is performed, wherein the steps a) and b) are performed in a separate processing space.

The fifth aspect is the film forming method according to the fourth aspect, wherein the step a) includes a step of advancing the reactive sputtering while supplying a sputter gas and a first amount of oxygen to the processing space a1) and a2) advancing the reactive sputtering while supplying a sputter gas and a second amount of oxygen smaller than the first amount to the processing space, wherein the step a1) and the step a2) As shown in Fig.

A sixth aspect of the present invention is directed to the film forming method according to any one of the first to third aspects, wherein the film formation method further comprises the steps of: d) forming, in a chamber in which an inner space forms one processing space and one sputter source is disposed in the processing space A step of holding the object at a position facing the sputter source; and e) a step of changing an amount of oxygen supplied to the processing space, wherein in a state where oxygen is supplied to the processing space, The process a) is performed, and the process b) is performed while the supply of oxygen to the process space is stopped.

A seventh aspect is the film forming method according to any one of the first to sixth aspects, wherein the object is a silicon substrate.

According to the first aspect, a film having a laminated structure of an aluminum oxide film and an aluminum film can be formed. Here, since the aluminum oxide film is formed by reactive sputtering, the aluminum oxide film can be formed at a sufficient rate. In addition, microscopic irregularities exist on the surface of the film formed by sputtering. In this case, since a separate film is formed by laminating on the film formed by sputtering, the two films are firmly adhered by the anchor effect. Here, the object on which one film is formed is not exposed to the atmosphere, and the other film is formed by being laminated on the film formed on the object, so that impurities are hardly adsorbed on the surface of the film formed first. Therefore, it is difficult to cause a problem that the adhesion between the initially formed film and the film to be laminated thereon is damaged by impurities or the like, and the two films adhere well. As described above, according to the first embodiment, it is possible to form a film having excellent characteristics at a sufficient rate.

According to the second aspect, an aluminum film is formed on the aluminum oxide film. Since the surface of the aluminum oxide film immediately after the film formation is relatively active, the impurities are particularly easily adsorbed. In the film obtained here, the aluminum oxide film is covered with the aluminum film without exposing the surface of the aluminum oxide film. Therefore, it is possible to obtain a film in which impurities are hardly adsorbed on the surface.

According to the third aspect, an upper layer portion of the aluminum oxide film is formed while a relatively small amount of oxygen is supplied to the processing space, and an aluminum film is formed thereon. According to this configuration, the adhesion between the aluminum oxide film and the aluminum film can be particularly enhanced.

According to the fourth and fifth aspects, the object is transported in the chamber partitioned by the plurality of processing spaces, whereby a series of processes are performed on the object. According to this configuration, as compared with the case where the chambers are provided for each of a plurality of film forming processes, the size of the chambers can be made compact, and the processing efficiency can be increased.

According to the sixth aspect, it is possible to form a film having a laminated structure in which the film structure of the aluminum oxide film and the aluminum film gradually changes in the object by changing the amount of oxygen supplied to the processing space. According to this configuration, the configuration of the apparatus can be simplified.

According to the seventh aspect, a passivation film excellent in electrical characteristics and excellent in sealing characteristics can be formed at a sufficient rate.

1 is a schematic diagram showing a schematic configuration of a film forming apparatus.
Fig. 2 is a schematic diagram showing a schematic configuration of a film forming unit. Fig.
3 is a schematic diagram showing a schematic configuration of a sputter source.
4 is a view showing the flow of processing executed in the film formation unit.
5 is a view showing a flow of processing executed on a substrate.
6 is a view schematically showing a film formed in the film forming unit.
7 is a schematic diagram showing a schematic configuration of a film forming unit according to a modified example.
8 is a view showing the flow of processing executed in the film forming unit according to the modification.

Hereinafter, an embodiment will be described with reference to the drawings. The following embodiments are illustrative of the present invention and are not limitative of the technical scope of the present invention. In the drawings, for the sake of easy understanding, the dimensions and the numbers of the respective parts may be exaggerated or simplified. In some drawings, XYZ orthogonal coordinate axes are attached for explaining the directions. The direction of the Z axis in this coordinate axis indicates the direction of the vertical line, and the XY plane is the horizontal plane.

<1. Overall configuration>

The overall structure of the film forming apparatus 100 will be described with reference to Fig. Fig. 1 is a diagram schematically showing a schematic configuration of the film formation apparatus 100. Fig. In FIGS. 2 and 7, which are referred to in FIGS. 1 and 2, the inside of the chamber is viewed through the side wall of the chamber.

In the film forming apparatus 100, the film deposition object is a substrate (concretely, for example, a p-type silicon substrate of a solar cell) 9. Here, the substrate 9, which is a film deposition object, is placed on the upper surface of the plate-like carrier 90. That is, a plurality of substrates 9, for example, are provided on the carrier 90 with the carrier 90 (the surface opposite to the light incident surface) of the object surface on which the film is to be formed And are fixed to the carrier 90 (see Fig. 2).

The film forming apparatus 100 is provided with a plurality of process chambers (specifically, a plurality of process chambers), for example, between a pair of lock chambers (specifically, the load lock chamber 110 and the unload lock chamber 150) (Film forming chamber 120, film forming chamber 130, and cooling chamber 140) are connected in a line shape.

The load lock chamber 110 and the unlocking chamber 150 are chambers constituting a load lock chamber and are used to keep the process chambers 120, 130 and 140 in a vacuum ). The load lock chamber 110 constitutes a load lock chamber for bringing the unprocessed substrate 9 into the heating chamber 120 and the unload lock chamber 150 constitutes a load lock chamber for transferring the unprocessed substrate 9 from the cooling chamber 140 to the substrate And a load lock chamber for carrying out the load lock chamber 9 is formed.

The internal space of the heating chamber 120 forms a processing space for heating the substrate 9. That is, in the heating chamber 120, heaters 121 are arranged on the upper and lower sides of the conveying path L, which will be described later, and the heaters 121 are conveyed in the heating chamber 120 The substrate 9 is heated.

The film forming chamber 130 and the elements disposed therein constitute a film forming unit 1 for forming a film on the substrate 9. The film forming unit 1 will be described in more detail later.

The inner space of the cooling chamber 140 forms a processing space for cooling the substrate 9. That is, inside the cooling chamber 140, a cooling plate 141 is disposed on each of the upper side and the lower side of the transport path L, which will be described later, and the cooling plate 141 is disposed inside the cooling chamber 140 And the substrate 9 to be conveyed is cooled.

A gate 160 is disposed between both ends of each of the lock chambers 110 and 150 and each of the processing chambers 120, 130 and 140. The gate 160 is switchable between a state in which the gate 160 is connected to the adjacent chamber (open state) and a state in which the adjacent chamber is shut off (closed state).

A high vacuum exhaust system 170 is connected to each of the chambers 110, 120, 130, 140, and 150 so that the internal space of each of the chambers 110, 120, 130, 140, Respectively.

A horizontal transport path L penetrating each of the chambers 110, 120, 130, 140, and 150 is defined in the chambers 110, 120, 130, 140, have. The film forming apparatus 100 has a carrying section 180 for carrying a carrier 90 (that is, a carrier 90 on which a plurality of substrates 9 are mounted) along the carrying path L. More specifically, the conveying unit 180 is disposed in each of the chambers 110, 120, 130, 140, and 150 in a horizontal direction perpendicular to the conveying path L A pair of conveying rollers 181 disposed opposite to each other with the conveying path L therebetween, and a driving unit (not shown) for rotationally driving the conveying rollers 181 in synchronism with each other. A plurality of pairs of conveying rollers 181 are formed along the extending direction of the conveying path L (X direction in the illustrated example). In this configuration, the carrier 90 rotates along the conveying path L by rotating the conveying rollers 181 while coming into contact with the bottom edge of the carrier 90 (the end edge on the + Y side) (Arrow AR180) in a predetermined direction (in the illustrated example, + X direction).

In the film formation apparatus 100, the load lock chamber 110, the heating chamber 120, the film formation chamber 130, the cooling chamber 140, and the cooling chamber 140 are formed from the upstream side (-X side) And the unload lock chamber 150 are arranged in this order. Then, the substrate 9 provided in the carrier 90 passes through the chambers in the order of arrangement, and the predetermined processing is performed in each chamber. That is, the substrate 9 loaded into the film forming apparatus 100 through the load lock chamber 110 is first carried into the heating chamber 120, where the heat treatment is performed. Subsequently, the substrate 9 after the heat treatment is carried into the film formation chamber 130, and the film formation process is performed here. The substrate 9 after the film formation process is subsequently carried into the cooling chamber 140, where the cooling process is performed. The substrate 9 after the cooling process is taken out of the film formation apparatus 100 through the unload lock chamber 150. However, the heat treatment and the cooling treatment are not necessarily indispensable, and may be omitted depending on the process design.

The film forming apparatus 100 further includes a control unit 190 that is electrically connected to the respective constituent elements thereof and controls each constituent element. Specifically, the control unit 190 includes, for example, a CPU for performing various arithmetic processing, a ROM for storing programs and the like, a RAM serving as a work area for arithmetic processing, a hard disk for storing programs and various data files, And a data communication unit having a data communication function through a bus line or the like are connected to each other by a general computer. The control unit 190 is connected to an input unit such as a display, a keyboard, and a mouse for performing various displays. In the film formation apparatus 100, the processing specified for the substrate 9 is executed under the control of the control section 190. [

<2. Film forming unit 1>

<2-1. Overall configuration>

The overall structure of the film forming unit 1 will be described with reference to Fig. Fig. 2 is a schematic diagram showing the entire structure of the film formation unit 1. Fig.

The film forming unit 1 is a processing unit for forming a film on a substrate 9 as an object by magnetron sputtering. The film forming unit 1 specifically includes a film forming chamber 130 and a plurality of (four in the illustrated example) sputter sources 10 disposed therein. A plurality of sputter sources 10 are arranged in a line along an axis (X axis) parallel to the conveying path L (see Fig. 1) of the carrier 90. In the following description, when a plurality of sputter sources 10 are to be distinguished, the "first sputter source 10a", the "second sputter source 10", and the " Source 10b "," third sputter source 10c ", and" fourth sputter source 10d ".

The film forming unit 1 further includes shielding plates 20 disposed on both sides of the respective sputtering sources 10. The shield plate 20 functions as a shield for limiting the range of scattering of plasma or spatter generated in the sputter source 10. [ A space partitioned by the shielding plates 20 on both sides of the first sputter source 10a is hereinafter also referred to as " first processing space Va. &Quot; A space partitioned by the shielding plates 20 on both sides of the second sputter source 10b is also referred to as " second processing space Vb ". The space partitioned by the shielding plates 20 on both sides of the third sputter source 10c is also referred to as " third processing space Vc ". A space partitioned by the shielding plates 20 on both sides of the fourth sputter source 10d is also referred to as " fourth processing space Vd " hereinafter.

That is, the inner space of the film formation chamber 130 is partitioned into a plurality of (four in this example) processing spaces Va, Vb, Vc, and Vd by a plurality of shielding plates 20, One sputter source 10 is disposed in each of the spaces Va, Vb, Vc, and Vd.

The film forming unit 1 further includes a cooking cavity 30 disposed between the third processing space Vc and the fourth processing space Vd. As described above, the film forming unit 1 is provided with a high vacuum exhaust system 170 for decompressing the internal space of the film forming chamber 130. The high vacuum exhaust system 170 is arranged on the -X side (That is, on the upstream side in the carrying direction of the carrier 90). The cooking cavity 30 adjusts the exhaust conductance between the high vacuum exhaust system 170 and the fourth processing space Vd. The cooking cavity 30 is provided with a resistance for making it difficult to introduce the atmosphere in the first processing space Va, the second processing space Vb and the third processing space Vc into the fourth processing space Vd (Barriers).

The film forming unit 1 further includes a heater 40 for heating the substrate 9 to be transported in the film forming chamber 130. The heater 40 is disposed, for example, on the upper side of the conveying path L.

The film forming unit 1 also has a gas supply part 50 for supplying gas to each of the four processing spaces Va, Vb, Vc and Vd. More specifically, the gas supply unit 50 includes a first processing space Va, a second processing space Vb, a third processing space Vc, and a fourth processing space Vd. An argon supply portion 51 for supplying a sputter gas (here, for example, argon (Ar) gas) to each of the three processing spaces (-X side) in the carrying direction of the carrier 90 An oxygen supply unit 52 for supplying a reactive gas (here, oxygen (O 2) gas) to each of the first processing space Va, the second processing space Vb, and the third processing space Vc, Respectively.

Specifically, the argon supply unit 51 includes, for example, an argon supply source 511 for supplying argon and an argon supply line 512. The argon supply pipe 512 is connected to the argon supply source 511 at one end and branched at four ends so that each branch end communicates with each of the four processing spaces Va, Vb, Vc, and Vd. (Specifically, a discharge port 16 (see FIG. 3) formed corresponding to each of the sputter sources 10a, 10b, 10c, and 10d). Further, supply valves 513a, 513b, 513c, and 513d are provided in each of the four paths of the ends where the argon supply pipe 512 branches off. The first supply valve 513a regulates the amount of argon supplied to the first processing space Va under the control of the control unit 190 and the second supply valve 513b regulates the amount of argon The third supply valve 513c controls the amount of argon supplied to the third processing space Vc under the control of the control unit 190 and the amount of argon And the fourth supply valve 513d adjusts the amount of argon supplied to the fourth processing space Vd under the control of the control unit 190. [ It is preferable that the supply valves 513a, 513b, 513c, and 513d are valves that can automatically adjust the flow rate of the gas flowing through the piping. More specifically, it is preferable to include a mass flow controller or the like Do.

Specifically, the oxygen supply unit 52 includes, for example, an oxygen supply source 521 serving as an oxygen supply source and an oxygen supply pipe 522. One end of the oxygen supply pipe 522 is connected to the oxygen supply source 521 and the other end is branched into three branches. Each branch end is connected to the three processing spaces Va, Vb, Vc on the upstream side in the carrying direction (Refer to Fig. 3) formed corresponding to each of the discharge ports (specifically, the first sputter source 10a, the second sputter source 10b, and the third sputter source 10c) . In addition, supply valves 523a, 523b, and 523c are provided in each of the three paths of the branched end of the oxygen supply pipe 522. The first supply valve 523a regulates the amount of oxygen supplied to the first processing space Va under the control of the control unit 190 and the second supply valve 523b regulates the amount of oxygen supplied to the control unit 190 The third supply valve 523c regulates the amount of oxygen supplied to the third processing space Vc under the control of the control unit 190. The control unit 190 controls the amount of oxygen supplied to the second processing space Vb Adjust the amount. Each of the supply valves 523a, 523b, and 523c is preferably a valve capable of automatically regulating the flow rate of the gas flowing through the pipe. Specifically, it is preferable to include a mass flow controller or the like.

<2-2. Sputter source 10>

Next, the sputter source 10 will be described with reference to FIG. 3 is a diagram schematically showing the configuration of the sputter source 10. As shown in Fig. The four sputter sources 10 included in the film forming unit 1 all have the same configuration.

The sputter source 10 is a combination of a magnetron sputter source and a plasma source. Specifically, the sputter source 10 includes a target 8, a base plate (cathode) 11, a sputter power source 12, a magnet 13, an anode 14, And a plasma generator 15. The sputter source 10 may also include a mechanism (not shown) for cooling the target 8, the base plate 11, the inductively coupled antenna 151 of the inductively coupled plasma generator 15, Respectively.

Here, as the target 8, an aluminum target formed of an aluminum (single metal aluminum) material is used. The target 8 is held in a horizontal posture by a target holding portion (not shown) at a position facing the carrier path L of the carrier 90 at a predetermined distance. That is, the target 8 is placed on the substrate 9 (that is, the substrate 9 provided on the carrier 90 conveyed along the conveyance path) in parallel with the posture, . However, the target 8 is held in the film forming chamber 130 in a state insulated from the film forming chamber 130.

The base plate 11 is in contact with the target 8 from below the target 8. The sputtering power source 12 applies a sputtering voltage to the base plate 11. Here, the sputter voltage may be, for example, a DC voltage of a negative voltage, a pulse voltage of a negative voltage and a positive voltage, or an AC sputter voltage to which a negative bias voltage is added. An electric field is generated by applying a sputter voltage to the base plate 11 (and further to the target 8), and a plasma (first plasma) is generated by this electric field.

The magnet 13 is disposed below the base plate 11. The magnet 13 is a magnet for a magnetron sputtering. The base plate 11 and the magnet 13 are collectively referred to as a " magnetron cathode ". The magnet 13 is formed of, for example, a permanent magnet, and forms a static magnetic field (magnetron magnetic field) in the vicinity of the surface of the target 8. The plasma generated by the electric field is confined in the vicinity of the surface of the target 8 by forming this amagnetic field.

The maximum value of the horizontal magnetic flux density formed by the magnet 13 on the surface of the target 8 is 20 mT to 20 mT in order to support the generation of plasma by the magnetron cathode in the inductively coupled plasma generating part 15 described later. 50 mT (milli tesla). When there is no support (plasma assist) by the inductively-coupled plasma generator 15, a horizontal magnetic flux density of about 60 mT to 100 mT is required on the surface of the target 8. As a result of performing the plasma assist, Sufficient plasma can be generated.

The anode 14 is disposed on the side of the base plate 11 at a distance from the base plate 11 (i.e., in a non-contact state with the base plate 11). The upper portion of the anode 14 is bent in the direction approaching the target 8 and reaches the end portion. The end portion is disposed in proximity to the side surface of the target 8 in a non-contact state.

The inductively coupled plasma generator 15 assists (assists) the generation of plasma by the magnetron cathode. Concretely, the inductively coupled plasma generating section 15 includes two inductively coupled type antennas 151 which are inductively coupled type high frequency antennas. Specifically, each inductively coupled antenna 151 is formed by bending a metallic pipe-shaped conductor into a U-shape and covering the conductor with a dielectric such as quartz.

The two inductively coupled antennas 151 are arranged with the target 8 interposed therebetween. Specifically, each inductively coupled antenna 151 is disposed along the side surface of the target 8 without contacting the side surface thereof. The inductively-coupled antenna 151 is disposed on the side of the protruding side of the inductively coupled antenna 151 (preferably a position slightly smaller (several centimeters below the corresponding end) And the height position of the target (151) and the target (8) is adjusted. However, the inductively coupled antenna 151 is fixed in the film forming chamber 130 in a state of being insulated from the film forming chamber 130.

One end of each inductively coupled antenna 151 is connected to a high frequency power supply 153 through a matching circuit 152. The other end of each inductively coupled antenna 151 is grounded. In this configuration, when a high frequency current (specifically, a high frequency current of, for example, 13.56 MHz) flows from the high frequency power supply 153 to each of the inductively coupled type antennas 151, (High frequency induction electric field) accelerates electrons to generate plasma (inductively coupled plasma (ICP)) (second plasma). The generated plasma is confined in the surface portion of the target 8 by the static magnetic field formed in the vicinity of the target 8 together with the plasma (first plasma) generated by the above electric field Loses.

As described above, the inductively coupled antenna 151 is U-shaped. The U-shaped inductively coupled antenna 151 is equivalent to an inductively coupled antenna having a number of turns of less than one and has a lower inductance than an inductively coupled antenna having a number of turns of one or more times. The generated high frequency voltage is reduced, and the high frequency fluctuation of the plasma potential due to the electrostatic coupling to the generated plasma is suppressed. Therefore, the excess electron loss due to fluctuation of the plasma potential to the ground potential is reduced, and the plasma potential is particularly suppressed to be low. Such an inductively coupled high frequency antenna is disclosed in Japanese Patent No. 3836636, Japanese Patent No. 3836866, Japanese Patent No. 4451392, and Japanese Patent No. 4852140.

In the film forming unit 1, a discharge port 16 is formed in correspondence with each sputter source 10. Concretely, the discharge port 16 is formed, for example, between each inductively coupled antenna 151 and the target 8. The gas supply unit 50 is connected to the discharge port 16 as described above and the gas supplied from the gas supply unit 50 to the discharge port 16 is supplied to the processing space in which the sputter source 10 is disposed do. However, the position of the discharge port 16 is not limited to the position between the target 8 and the inductively coupled antenna 151. However, it is preferable that the discharge port 16 is provided at a position corresponding to each of the two inductively coupled antennas 151.

<2-3. Operation of the film forming unit 1>

Next, the operation of the film formation unit 1 will be described with reference to Fig. 4 in addition to Fig. 2 and Fig. 4 is a view showing the flow of processing executed in the film formation unit 1. Fig. The operations described below are executed under the control of the control unit 190. [

When the carrier 90 provided with the substrate 9 (that is, the substrate 9 subjected to the heat treatment in the heating chamber 120) is carried in the film formation chamber 130, the carrier 90 on the inlet side of the deposition chamber 130 The gate 160 is closed (step S1). The film deposition chamber 130 is always kept at a high vacuum by the high vacuum exhaust system 170.

Subsequently, the gas supply unit 50 supplies gas to each of the four processing spaces Va, Vb, Vc, and Vd (step S2). Specifically, the gas supply unit 50 is provided with three processing spaces (that is, the first processing space Va, the second processing space Vb, and the third processing space Vc) on the upstream side in the carrying direction, Argon as a sputter gas and oxygen as a reactive gas are supplied and only argon as a sputter gas is supplied to the processing space at the most downstream side in the carrying direction (i.e., the fourth processing space Vd).

The gas supply unit 50 is provided with two processing spaces (that is, the first processing space Va (Vb), Vb (I.e., the third processing space Vc) is supplied with oxygen of the first amount F1 and the remaining one processing space (i.e., the third processing space Vc) And supplies a second amount of oxygen F2 less than the amount F1. Here, if the minimum supply amount of oxygen required for forming an aluminum oxide (Al ₂ O ₃ ) film free from oxygen deficiency by reactive sputtering is referred to as a "reference amount F0", the first amount F1 is equal to the reference amount F0 ) And the second amount F2 is smaller than the reference amount F0 (F1? F0 > F2). That is, when the minimum value of the partial pressure of oxygen (oxygen partial pressure) in which the aluminum oxide film without oxygen deficiency is formed is referred to as a "reference partial pressure", the oxygen partial pressures in the first processing space Va and the second processing space Vb And the partial pressure of oxygen in the third processing space Vc becomes a value smaller than the reference partial pressure.

Frequency current of 13.56 MHz (for example, 13.56 MHz, for example) is applied from the high-frequency power supply 153 to the inductively coupled antenna 151 in each of the four sputter sources 10a, 10b, 10c, The sputter voltage is applied from the sputter power source 12 to the base plate 11 (step S3). Then, a plasma (inductively coupled plasma) is generated by a high frequency induction electric field around the inductively coupled antenna 151 (so-called plasma assist). Further, by applying a sputter voltage to the base plate 11, a high-density plasma is generated in the vicinity of the target 8. These two kinds of plasma are confined to the surface portion of the target 8 by the magnetism field formed by the magnet 13 in the vicinity of the target 8. [ Then, ions in the plasma atmosphere collide with the target 8 to cause aluminum (Al) atoms to protrude from the target 8 (so-called magnetron sputtering).

On the other hand, the carry section 180 moves the carrier 90 provided with the substrate 9 along the conveying path L (that is, along the array direction of the plurality of processing spaces Va, Vb, Vc and Vd) ) At a constant speed (step S4). The substrate 9 provided on the carrier 90 is configured so that the first processing space Va, the second processing space Vb, the third processing space Vc, and the fourth processing space Vd And the film forming process is sequentially performed in each processing space. The substrate 9 is provided on the carrier 90 with the rear surface facing the side opposite to the carrier 90 as described above and the carrier 90 is configured to move the carrier 90 to the substrate 90, So that the surface of the sputter source 10 is directed to the sputter source 10. That is, the substrate 9 held by the carrier 90 is transported in each processing space in a posture such that its back surface faces the target 8 of each sputter source 10.

Processing executed on the substrate 9 conveyed in the evaporation chamber 130 will be described with reference to Fig. Fig. 5 is a view showing the flow of processing performed on the substrate 9 carried in the film forming chamber 130. Fig.

The substrate 9 first passes through the first processing space Va, the second processing space Vb, and the third processing space Vc in this order.

Sputter gas and oxygen are supplied to each of the first processing space Va, the second processing space Vb and the third processing space Vc. In the state that the sputter gas and the oxygen are supplied, The target 8 is sputtered. Therefore, in each of the first processing space Va, the second processing space Vb, and the third processing space Vc, reactive sputtering proceeds and the substrate 9, which is disposed opposite to the target 8, An aluminum oxide film is formed by reactive sputtering. That is, while the substrate 9 held by the carrier 90 passes through the first processing space Va, the second processing space Vb, and the third processing space Vc in this order, An aluminum oxide film is formed on the back surface of the substrate 9. A preferable film thickness of the aluminum oxide film formed at the time of exiting the third processing space Vc is " 50 nm ".

However, in the first processing space Va and the second processing space Vb, oxygen of a first amount F1 which is equal to or larger than the reference amount F0 is supplied. In these processing spaces Va and Vb, Reactive sputtering proceeds under an environment of oxygen partial pressure equal to or higher than the above. Therefore, in the first processing space Va and the second processing space Vb, aluminum atoms sputtered from the target 8 are combined with a sufficient amount of oxygen to form a composition of Al ₂ O ₃ , An aluminum oxide film free from oxygen defects is formed on the back surface of the substrate 9 on which it is disposed (step S101).

On the other hand, in the third processing space Vc, only oxygen of the second amount F2, which is smaller than the reference amount F0, is supplied. Therefore, in the third processing space Vc, (That is, in a state in which the number of oxygen is insufficient), reactive sputtering proceeds. In this case, since the aluminum atom sputtered from the target 8 can not be combined with a sufficient amount of oxygen, an aluminum oxide film (Al-rich AlOx film) in which aluminum is excessively present is formed. That is, in the third processing space Vc, an aluminum oxide film (an aluminum oxide film without oxygen defects), which is formed on the back surface of the substrate 9 opposed to the target 8, (Step S102). The term " aluminum excess aluminum oxide film " means an aluminum oxide film having oxygen deficiency. Specifically, it is an aluminum atom that does not undergo a chemical reaction or a film containing aluminum atoms in a single body.

The substrate 9 (that is, the substrate 9 on which the aluminum oxide film is formed on the back surface) that has passed the third processing space Vc enters the fourth processing space Vd without being exposed to the atmosphere.

In the fourth processing space Vd, only the sputter gas is supplied, and the target 8 is sputtered with ions in the plasma atmosphere. Therefore, in the fourth processing space Vd, normal sputtering is performed instead of reactive sputtering, and an aluminum film is formed by sputtering on the back surface of the substrate 9 opposed to the target 8. That is to say, the substrate 9 held by the carrier 90 passes through the fourth process space Vd, and the aluminum oxide film formed on the back surface of the substrate 9 An aluminum oxide film that is excessively aluminum) is formed by laminating aluminum films (step S103). A preferable film thickness of the aluminum film formed at the time of exiting the fourth processing space Vd is " 2 mu m to 3 mu m ".

Further, in the fourth processing space Vd, the desired process is advanced, but the plasma assist is not essential. That is, supply of a high frequency current to the inductively coupled antenna 151 of the fourth sputter source 10d is not essential. However, when the plasma assist is performed, the aluminum film can be formed at a high deposition rate.

In this manner, a film having a laminated structure of an aluminum oxide film and an aluminum film (a passivation film) is formed on the back surface of the substrate 9 between the first processing space Va and the fourth processing space Vd. Is formed. That is, while the substrate 9 passes through the first processing space Va, the second processing space Vb, and the third processing space Vc in this order, the substrate 9 is oxidized An aluminum film (an aluminum oxide film whose upper layer portion is excess of aluminum) is formed. Then, the substrate 9 that has passed the third processing space Vc enters the fourth processing space Vd without being exposed to the atmosphere. The aluminum film is laminated on the aluminum oxide film formed on the back surface of the substrate 9 while the substrate 9 passes through the fourth processing space Vd.

The substrate 9 (that is, the substrate 9 on which the film having the laminated structure of the aluminum oxide film and the aluminum film is formed on the back side) out of the fourth processing space Vd is connected to the gate 160 And is then taken out of the film forming chamber 130. As described above, the substrate 9 taken out of the film formation chamber 130 is continuously carried into the cooling chamber 140, where the cooling processing is performed if necessary.

<3. Characteristics of Thin Film>

Next, the characteristics of the film formed by the film formation unit 1 will be described with reference to Fig. Fig. 6 is a diagram schematically showing the state of the film 7 formed by the film formation unit 1. Fig.

The film 7 having the laminated structure of the aluminum oxide film 71 and the aluminum film 72 is formed on the object 9 (substrate in the above example) in the film forming unit 1 as described above.

i. First feature

In the film forming unit 1, an aluminum oxide film 71 is formed on the object 9 by reactive sputtering. In sputtering (either reactive sputtering or normal sputtering), a combination of a plurality of atoms bonded together is formed to form a film. Therefore, when the film produced by sputtering is compared with, for example, a film produced by the ALD method, the surface of the former is rough. That is, the surface of the aluminum oxide film 71 produced in the film forming unit 1 is in a rough state (i.e., a state in which microscopic unevenness exists).

The aluminum atoms of the aluminum film 72 enter into the irregularities on the surface of the aluminum oxide film 71 when the aluminum film 72 is laminated on the aluminum oxide film 71 having irregularities on the surface, A strong anchor effect is generated between the aluminum film 72 and the aluminum film 72. That is, in the film 7 formed of the film forming unit 1, the aluminum oxide film 71 and the aluminum film 72 are firmly adhered to each other by the anchor effect, and the two films 71 and 72 It is in a state that it is difficult to peel off.

ii. Second feature

As described above, in the film forming unit 1, when the object 9 passes through the first processing space Va, the second processing space Vb, and the third processing space Vc in this order , An aluminum oxide film 71 is formed on the object 9. The object 9 leaving the third processing space Vc enters the fourth processing space Vd without being exposed to the atmosphere and is stacked on the aluminum oxide film 71 formed first, A film 72 is formed.

The surface of the aluminum oxide film 71 immediately after the film formation is relatively highly reactive and is in a state where it is easy to adsorb impurities (for example, nitrogen atom, nitrogen molecule, OH group (hydroxyl group) The adhesion between the films tends to be impaired by the impurities existing between the films when the aluminum film is laminated thereon. Here, the object 9 on which the aluminum oxide film 71 is formed is not exposed to the atmosphere, and the aluminum film 72 is formed by being laminated on the aluminum oxide film 71 formed on the object 9. In this configuration, the surface of the aluminum oxide film 71 is exposed to the atmosphere without being exposed to the atmosphere, and the aluminum film 72 is covered with the so-called lid, so that impurities are adsorbed on the surface of the aluminum oxide film 71 it's difficult. Therefore, it is unlikely that the adhesion between the aluminum oxide film 71 and the aluminum film 72 stacked thereon is damaged by impurities or the like, and the two films 71 and 72 adhere well.

iii. Third characteristic

As described above, in the third processing space Vc, reactive sputtering proceeds in a state in which a relatively small amount of oxygen is supplied (a state in which the number of oxygen is insufficient), so that the upper layer portion of the aluminum oxide film 71, (That is, a state in which an aluminum atom or a group aluminum atom is not included in a chemical reaction).

When the aluminum film 72 is formed by laminating on the aluminum oxide film 71, the aluminum atoms (the aluminum atoms that have not chemically reacted or the aluminum atoms in the single body) scattered in the surface layer of the aluminum oxide film 71 , The aluminum atoms of the aluminum film 72 are attracted with a strong bonding force in accordance with the metal bonding. As a result, the aluminum oxide film 71 and the aluminum film 72 are particularly strongly adhered to each other. That is, by forming the upper layer portion of the aluminum oxide film 71 in a state in which the number of oxygen atoms is insufficient, the aluminum oxide film 71 and the aluminum film 72 can be particularly strongly adhered to each other.

<4. Effect>

According to the above embodiment, the film 7 having the laminated structure of the aluminum oxide film 71 and the aluminum film 72 can be formed. Here, an aluminum oxide film 71 is formed by reactive sputtering. Reactive sputtering has a very rapid film formation rate as compared with, for example, the ALD method. Therefore, the aluminum oxide film 71 can be formed at a sufficient rate.

According to the above embodiment, as described above, the film 7 having excellent characteristics in which the aluminum oxide film 71 and the aluminum film 72 are hardly adhered to each other and is difficult to peel off can be formed.

In the above embodiment, both the aluminum oxide film 71 and the aluminum film 72 are formed using the aluminum target 8. Therefore, the control of the film formation process is simplified, and the device configuration can be simplified. Further, since the aluminum target 8 is inexpensive, the material cost can also be suppressed.

Further, according to the above embodiment, the aluminum film 72 is formed on the aluminum oxide film 71. Since the surface of the aluminum oxide film 71 immediately after the film formation is relatively active, impurities are particularly likely to be adsorbed. In the film 7 thus obtained, the surface of the aluminum oxide film 71 is not exposed, 72, respectively. Therefore, it is possible to obtain the film 7 in which impurities are hardly adsorbed on the surface.

According to the above embodiment, the substrate 9, which is an object, is conveyed in the film forming chamber 130 partitioned by the plurality of processing spaces Va, Vb, Vc, and Vd, . According to this configuration, as compared with the case where the chambers are provided for each of the plurality of film forming processes, the film forming chamber 130 can be made compact in size and the processing efficiency can be improved.

In the above-described embodiment, the object is a p-type silicon substrate 9 of a solar cell, and a laminated structure of the aluminum oxide film 71 and the aluminum film 72 is formed on the back surface of the substrate 9 (Passivation film) 7 is formed. The aluminum oxide film is effective for improvement of the conversion efficiency in the solar cell, and is excellent as a passivation film in terms of electrical characteristics and sealing properties. On the other hand, the aluminum oxide film has a drawback that cracks tend to occur and impurities are easily adsorbed on the surface. On the other hand, the aluminum film has an advantage of being able to easily realize a relatively high film formation rate, and is weak and liable to be damaged. Here, the passivation film 7 has a laminated structure of the aluminum oxide film 71 and the aluminum film 72, thereby achieving a high deposition rate, good electrical characteristics and sealing characteristics. That is, a passivation film excellent in electrical characteristics and excellent in sealing characteristics can be formed at a sufficient rate.

Further, in the above embodiment, the cooking cavity 30 is provided between the fourth processing space Vd and the third processing space Vc. The oxygen radicals or the like which are generated in the first to third processing spaces Va to Vc and not used for the reaction do not flow into the fourth processing space Vd, Exhausted from the high vacuum exhaust system 170, and discharged to the outside of the film formation chamber 130. Therefore, the aluminum film 72 formed on the back surface of the substrate 9 in the fourth processing space Vd can be formed to have a high purity that does not contain oxygen.

<5. Modifications>

<5-1. When one sputter source 10 is provided>

In the above embodiment, the film forming unit 1 is configured to include four sputter sources 10. However, the film forming unit may be configured to include, for example, one sputter source 10. [ Fig. 7 shows a film forming unit 1s having one sputter source 10. Fig.

The film forming chamber 130s provided in the film forming unit 1s has one processing space Vs formed therein and one sputter source 10 (hereinafter, referred to as " sputter source " (Also referred to as " 10s "). The film forming unit 1s has the same configuration as the film forming unit 1 related to the above embodiment, except that the number of the sputter sources 10 is different. In the figures, parts having the same configurations and functions as those of the above-described embodiment are denoted by the same reference numerals, and description of the corresponding parts is omitted.

The gas supply unit 50s for supplying the gas to the process space Vs is provided with a sputter gas (here, for example, argon) in the process space Vs in the same manner as the gas supply unit 50 according to the above- And an oxygen supply unit 52s for supplying a reactive gas (here, oxygen) to the process space Vs. The argon supply section 51s is connected to an argon supply source 511 and a discharge port whose one end is connected to the argon supply source 511 and the other end is connected to the discharge space (specifically, the sputter source 10s And an argon supply pipe 512 connected to the discharge port 16). Further, it has a supply valve 513s inserted in the path of the argon supply pipe 512. The supply valve 513s adjusts the amount of argon supplied to the processing space Vs under the control of the control unit 190. [ The oxygen supply section 52s includes an oxygen supply source 521 and an oxygen supply pipe 522 connected to the discharge port 16 whose one end is connected to the oxygen supply source 521 and the other end is connected to the process space Vs, Respectively. Further, it has a supply valve 523s inserted in the path of the oxygen supply pipe 522. The supply valve 523s adjusts the amount of oxygen supplied to the processing space Vs under the control of the control unit 190. [

The operation of the film formation unit 1s will be described with reference to Figs. 5 and 8 in addition to Fig. 7. Fig. 8 is a diagram showing the flow of processing executed in the film formation unit 1s. 5 is a diagram showing the flow of processing executed on the substrate 9 as described above. The operations described below are executed under the control of the control unit 190. [

When the carrier 90 provided with the substrate 9 (that is, the substrate 9 subjected to the heat treatment in the heating chamber 120) is loaded in the film forming chamber 130, the carry section 180 moves the carrier 90 Is moved to a predetermined processing position (specifically, a position such that the substrate 9 held by the carrier 90 is disposed directly above the target 8 of the sputter source 10s) The carrier 90 is kept stationary (step S11). That is, in the above-described embodiment, the substrate 9 is moved successively from the respective sputter sources 10 in a series of film forming processes while moving relative to the plurality of sputter sources 10a, 10b, 10c and 10d In this modification, the substrate 9 is subjected to a series of film forming processes from the sputter source 10s in a state where the substrate 9 is stationary with respect to one sputter source 10s.

On the other hand, when the carrier 90 provided with the substrate 9 is carried into the film forming chamber 130, the gate 160 at the inlet side of the film forming chamber 130 is closed (step S12). The inside of the chamber 130 is always kept at a high vacuum by the high vacuum exhaust system 170. The processing in step S11 and step S12 may be either performed first or in parallel.

Subsequently, the gas supply unit 50 starts supply of the gas to the process space Vs (step S13). In this step, however, the gas supply unit 50 supplies argon, which is a sputter gas, and oxygen in the first amount F1, which is equal to or greater than the reference amount F0, to the processing space Vs. Therefore, the oxygen partial pressure of the processing space Vs becomes equal to or higher than the reference partial pressure.

A high frequency current (specifically, a high frequency current of, for example, 13.56 MHz) flows from the high frequency power supply 153 to the inductively coupled antenna 151 in the sputter source 10s, 12 to the base plate 11 (step S14).

In this step, the sputter gas and oxygen are supplied to the processing space Vs, and the target 8 is sputtered with ions in the plasma atmosphere in a state where the plasma assist is performed. Therefore, in this step, reactive sputtering proceeds, and an aluminum oxide film is formed on the rear surface of the substrate 9 opposed to the target 8 by reactive sputtering. In this step, oxygen above the reference amount F0 is supplied to the processing space Vs, and in the processing space Vs, reactive sputtering proceeds under the environment of oxygen partial pressure equal to or higher than the reference partial pressure. Therefore, aluminum atoms sputtered from the target 8 are combined with a sufficient amount of oxygen to form a composition of Al ₂ O ₃ , and on the back surface of the substrate 9 opposed to the target 8, aluminum oxide A film is formed (step S101).

When the predetermined time has elapsed after the process of step S14 is performed, the gas supply unit 50 reduces the amount of oxygen supplied to the process space Vs (step S15). Specifically, the gas supply unit 50 switches the amount of oxygen supplied to the sputter source 10 from a first amount F1 that is equal to or greater than the reference amount F0 to a second amount that is smaller than the reference amount F0 do. Therefore, after the processing of step S15 is performed, the oxygen partial pressure of the processing space Vs becomes smaller than the reference partial pressure.

Even in the step after the processing of step S15 is performed, the target 8 is sputtered with ions in the plasma atmosphere in a state in which the sputter gas and oxygen are supplied to the processing space Vs and the plasma assist is performed. Therefore, even in this step, reactive sputtering proceeds, and an aluminum oxide film is formed on the rear surface of the substrate 9 opposed to the target 8 by reactive sputtering. At this stage, however, only a small amount of oxygen is supplied to the processing space Vs than the reference amount F0. Therefore, in the processing space Vs, under an environment of oxygen partial pressure lower than the reference partial pressure (that is, Reactive sputtering proceeds. In this case, as described above, since aluminum atoms sputtered from the target 8 can not be combined with a sufficient amount of oxygen, an aluminum oxide film in which aluminum is excessively present is formed. That is, in this step, an aluminum-excess aluminum oxide film is formed on the aluminum oxide film (aluminum oxide film without oxygen defects), which is formed on the back surface of the substrate 9 opposed to the target 8, (Step S102).

When the predetermined period of time has elapsed since the processing of step S15 (specifically, for example, when the aluminum oxide film formed on the back surface of the substrate 9 reaches a desired thickness (for example, a thickness of 50 nm) , The gas supply unit 50 stops the supply of oxygen to the process space Vs (step S16). Also, the supply of the high-frequency current to the inductively-coupled antenna 151 may be stopped while the supply of oxygen is stopped.

In the step after the process of step S16 is performed, only the sputtering gas is supplied to the processing space Vs, and the target 8 is sputtered with ions in the plasma atmosphere. Therefore, in this step, the normal sputtering is performed instead of reactive sputtering, and an aluminum film is formed by sputtering on the back surface of the substrate 9 opposed to the target 8. That is, in this step, an aluminum film is laminated on the aluminum oxide film (the upper layer portion is an aluminum oxide film that is excess of aluminum) formed on the back surface of the substrate 9 (Step S103).

(For example, when the film thickness of the aluminum film formed on the back surface of the substrate 9 is smaller than a predetermined thickness (for example, " 2 m to 3 m " ), The gas supply unit 50 stops the supply of argon to the processing space Vs. Then, after the high-frequency current to the inductively coupled antenna 151 is stopped and the application of the sputter voltage to the base plate 11 is stopped, the carrier 90 provided with the substrate 9 is discharged from the deposition chamber 130 (Step S17).

It should be noted that until at least the supply of argon to the processing space Vs is stopped, the film forming chamber 130 is not vacuum-broken and the substrate 9 is subjected to the processing from step S101 to step S103, The substrate 9 is not exposed to the atmosphere. That is, the substrate 9 on which the aluminum oxide film is formed is not exposed to the atmosphere, and the aluminum film is subsequently formed on the aluminum oxide film formed on the substrate 9.

According to this modified example, by changing the amount of oxygen supplied to the processing space Vs, the laminated structure of the aluminum oxide film and the aluminum film (particularly, a laminated structure in which the film structure is gradually changed) is formed on the substrate 9 as the object It can form a film. According to this configuration, the configuration of the apparatus can be simplified.

In the above example, the gas supply unit 50 gradually reduces the amount of oxygen supplied to the process space Vs, and the gas supply unit 50 gradually increases the oxygen supply amount with time ). Further, the processing in step S15 is not necessarily required. However, when the processing in step S15 is performed, an aluminum oxide film 71 in which the upper layer portion is excess of aluminum is formed, and as a result, the adhesion between the aluminum oxide film 71 and the aluminum film 72 Can be improved.

<5-2. Other Modifications>

In the above embodiment, the same amount of oxygen is supplied to the first processing space Va and the second processing space Vb, and the amount of oxygen supplied to the first processing space Va and the amount of oxygen supplied to the second processing space Vb ) Need not be the same value. However, it is preferable that the supply amount of oxygen to the second processing space Vb is equal to or less than the supply amount of oxygen to the first processing space Va. It is also preferable that the supply amount of oxygen to the second processing space Vb is equal to or greater than the supply amount to the third processing space Vc.

In the above embodiment, the amount of oxygen supplied to the third processing space Vc is smaller than the amount of oxygen supplied to the third processing space Vc, 2 processing space (Vb). For example, oxygen of the first amount F1 may be supplied to the entire first processing space Va, the second processing space Vb, and the third processing space Vc.

In addition, in the above-described embodiment, in place of setting the supply amount of oxygen to the fourth processing space Vd to zero (or making the supply amount of oxygen zero), the high frequency The supply of the current may be stopped. In the state where the supply of the high frequency current to the inductively coupled antenna 151 of the sputter source 10 is stopped, even if oxygen exists in the fourth processing space Vd, a normal sputtering process is performed instead of reactive sputtering . Therefore, even with this configuration, the formation of the aluminum film can be advanced in the fourth processing space Vd.

In the above embodiment, the aluminum film 72 is laminated on the aluminum oxide film 71. However, the order of lamination is not limited to this, and an aluminum oxide film (aluminum oxide film) 71 may be stacked. That is, after the process of forming the aluminum film 72 is first performed on the substrate 9, a process of laminating the aluminum film 72 on the aluminum film 72 to form the aluminum oxide film 71 may be performed. In order to perform such processing, for example, in the above-described embodiment, the gas supply unit 50 is disposed in the three processing spaces (that is, the second processing space (Vb), the third processing Argon which is a sputter gas and oxygen which is a reactive gas are supplied to each of the first processing space Vc and the fourth processing space Vd and the processing space at the most upstream side in the carrying direction ), Only argon, which is a sputter gas, may be supplied. In this case, of the three processing spaces Vb, Vc, and Vd on the downstream side in the carrying direction, two processing spaces (that is, the third processing space Vc, The first amount F1 is supplied to each of the first processing space Vd and the fourth processing space Vd and the first amount F1 is supplied to the remaining one processing space It is also preferable to supply oxygen of the second amount F2 which is less than that of the second amount F2.

Further, the number of processing spaces defined in the film forming chamber 130 is not limited to four or one. Further, one or more sputter sources 10 may be disposed in each processing space.

In the embodiment described above, of the four processing spaces Va, Vb, Vc and Vd defined in the film forming chamber 130, three processing spaces (i.e., the first processing space Va, The processing for forming the aluminum oxide film in the processing space Vb and the processing space Vc for the third processing is advanced and the processing for forming the aluminum film in the remaining one processing space (i.e., the fourth processing space Vd) The ratio of the number of processing spaces for advancing the formation of the aluminum oxide film to the number of processing spaces for advancing the formation of the aluminum film can be arbitrarily selected depending on processing conditions and the like. When the formation of the aluminum oxide film is advanced in a plurality of processing spaces, a small amount of oxygen is supplied to the processing space located beside the processing space for advancing the formation of the aluminum film out of the plurality of processing spaces It is also preferable to use a configuration.

In the above-described embodiment, a plurality of sputter sources 10 are disposed in one film forming chamber 130. In addition to accommodating the respective sputter sources in an individual chamber, each chamber is connected to a vacuum path As shown in Fig. In this case, the inner space of each of the plurality of chambers connected through the vacuum path forms one processing space.

The chamber structure of the film forming apparatus 100 according to the above embodiment is not limited to those exemplified above. For example, at least one of the heating chamber 120 and the cooling chamber 140 may be omitted from the deposition apparatus.

Further, the structure of the film formation unit 1 is not limited to those exemplified above. For example, the film forming unit 1 may be configured such that the cooking open / close plate 30 is not provided.

Also, the configuration of each sputter source 10 is not limited to those described above. For example, the number of the inductively coupled antennas 151 disposed in each sputter source 10 is not limited to two, and the number of the inductively coupled antennas 151 may be determined depending on the size of the substrate 9, It can be selected appropriately. The sputter gas does not necessarily have to be argon, but may be, for example, krypton (Kr) gas.

The film forming method according to the present invention is suitable for the production of a passivation film of a solar cell silicon substrate (in particular, a back passivation film of a p-type silicon substrate) as described above. It can be applied to the production of various other films. For example, various barrier films, sealing films for organic EL displays, sealing films for solar cells, and the like.

1, 1s: film forming unit
10, 10a, 10b, 10c, 10d, 10s: sputter source
11: base plate
12: Power for sputtering
13: Magnet
14: anode
15: Inductively Coupled Plasma Generating Unit
151: Inductively Coupled Antenna
153: High frequency power source
16:
20: Shield plate
30: Cooking dish
40: heater
50, 50s: gas supply part
51: argon supply part
52:
8: Target
9: substrate
90: Carrier
100: Deposition device
130: Tabernacle chamber
170: High vacuum exhaust system
180:
Va, Vb, Vc, Vd, Vs: processing space

Claims

A film forming method for forming a film on an object by magnetron sputtering,
a) generating a first plasma in a processing space by applying a sputter voltage to an aluminum target, and applying a second plasma of inductively coupled type to the processing space by flowing a high frequency current through an inductively coupled antenna having less than one winding number Forming an aluminum oxide film on the object by reactive sputtering by supplying sputter gas and oxygen to the processing space while sputtering the aluminum target while generating the aluminum oxide film;
b) supplying a sputter gas to the processing space while generating at least the first plasma in the processing space before or after the a), sputtering the aluminum target, and forming an aluminum film on the object And a step of forming,
Wherein the other of the aluminum oxide film and the aluminum film is formed by laminating the other film on the one film formed on the object without exposing the object on which the film is formed to the atmosphere.

The method according to claim 1,
Wherein the step b) is performed after the step a).

The method of claim 2,
Wherein the step a)
a1) advancing the reactive sputtering while supplying a sputter gas and a first amount of oxygen to the processing space;
a2) advancing the reactive sputtering while supplying a sputter gas and a second amount of oxygen less than the first amount to the processing space,
Wherein the a2) process is performed after the a1) process.

The method according to any one of claims 1 to 3,
c) a step of transporting the object along the arrangement direction of the plurality of processing spaces in a chamber in which an inner space is divided into a plurality of processing spaces and a sputter source is disposed in each of the plurality of processing spaces, Respectively,
Wherein the steps a) and b) are performed in a separate processing space.

The method of claim 4,
Wherein the step a)
a1) advancing the reactive sputtering while supplying a sputter gas and a first amount of oxygen to the processing space;
a2) advancing the reactive sputtering while supplying a sputter gas and a second amount of oxygen less than the first amount to the processing space,
Wherein the a1) and the a2) processes are performed in separate processing spaces.

The method according to any one of claims 1 to 3,
d) holding the object in a position opposite to the sputter source in a chamber in which an inner space forms one processing space and one sputter source is disposed in the processing space;
e) changing the amount of oxygen supplied to the processing space,
In the state in which oxygen is supplied to the processing space, the step a) is performed,
Wherein the step (b) is carried out while the supply of oxygen to the processing space is stopped.

The method according to any one of claims 1 to 3,
Wherein the object is a silicon substrate.