WO2011052355A1

WO2011052355A1 - Reactive sputtering film-forming apparatus and method for manufacturing film using same

Info

Publication number: WO2011052355A1
Application number: PCT/JP2010/067562
Authority: WO
Inventors: 英和鈴木
Original assignee: キヤノンアネルバ株式会社
Priority date: 2009-10-28
Filing date: 2010-10-06
Publication date: 2011-05-05

Abstract

Disclosed is a reactive sputtering film-forming apparatus provided with a mask, wherein local increase of the atomic concentration of film-forming components in the outer circumferential portion of a substrate is reduced, while reducing generation of dusts. Also disclosed is a method for manufacturing a film using the reactive sputtering film-forming apparatus. The reactive sputtering film-forming apparatus is provided with: a chamber (1); a substrate holder (6) for disposing the substrate (5); a mask (8); and a first gas supply port (10), through which a gas containing a reactive gas is supplied to the inside of the chamber (1). The mask (8) and the substrate holder (6) are configured such that gaps (15, 17) are formed between the mask (8), and the substrate holder (6) and the substrate (5), at least at the time of performing reactive sputtering. The reactive sputtering film-forming apparatus is also provided with a second gas supply port (16), an inert gas is supplied from the second gas supply port, and entry of the reactive gas from the periphery of the substrate holder (6) to the area having the substrate disposed thereon is suppressed.

Description

Reactive sputtering film forming apparatus and film manufacturing method using the same

The present invention relates to a reactive sputtering film forming apparatus for forming a film on a substrate by reactive sputtering, and a film manufacturing method using the same.

The sputter deposition apparatus strikes out the target material attached to the cathode with gas ions (sputtering), and deposits the target material particles (sputtered particles) generated thereby on the substrate arranged to face the target. Thus, an apparatus for forming a film on a substrate. Therefore, in the sputtering film forming apparatus, gas is introduced into the apparatus, electric power is applied to the target to generate plasma, and gas ions are generated in order to perform sputtering.

A reactive sputter film forming apparatus is known as the sputter film forming apparatus. In the reactive sputtering film forming apparatus, a reactive gas such as nitrogen (N ₂ ) or oxygen (O ₂ ) is introduced into the chamber together with an inert gas such as argon (Ar) for causing sputtering. The In such a reactive sputter deposition apparatus, target material particles are knocked out when Ar ions in the plasma strike the target, the target material particles react with the reactive gas, and these reaction products are applied to the substrate. accumulate. Further, when the concentration of the reactive gas is high, a compound layer made of the reactive gas is formed on the surface of the target, and these are deposited on the substrate by sputtering.

The film formed by the reactive sputter film forming apparatus is used for various purposes. For example, thin film transistors (TFTs) used in liquid crystal displays, barrier films such as TiN and MoN used in semiconductor wiring, and transparent conductive films such as indium tin oxide (ITO) used in liquid crystal displays and thin film solar cells, etc. Is mentioned. In recent years, in these applications, since the area of the substrate in the manufacturing process has been increased, it is required that the film thickness and quality of the film to be formed satisfy the desired uniformity even in a large area substrate.

In the reactive sputtering film forming apparatus, in order to improve the uniformity of the reactive gas atom concentration in the film, the reactive gas can be uniformly supplied to a space (film forming space) where the target and the substrate face each other. It is desirable. Various proposals have been made from this viewpoint (Patent Documents 1 and 2).

According to the sputter deposition apparatus according to Patent Document 1, there is provided a mechanism for allowing a reactive gas to flow outward from the central portion of the cathode unit along the target surface. According to the sputter film forming apparatus according to Patent Document 2, the gas pipe for introducing the reactive gas extending in the direction in which the targets are juxtaposed is provided on the back side of the plurality of targets arranged in parallel at a predetermined interval. An injection port for injecting reactive gas from the gas pipe toward the target is provided.

On the other hand, FIG. 1 of Patent Document 3 discloses a sputtering film forming apparatus provided with a shield called a mask or the like that prevents deposition of a film on an outer peripheral end of the substrate or a substrate holder on which the substrate is placed. . When sputtering is performed with this sputter deposition apparatus, the mask is arranged at a predetermined distance from the substrate holder and the substrate.

JP 2004-346406 A JP 2008-274366 A JP 2006-89793 A

However, when reactive sputter deposition is performed with a sputter deposition apparatus equipped with a mask, a problem arises in that the film quality is locally different at the outer periphery of the substrate in the vicinity of the mask. That is, when TiN is formed using Ti as a target, N ₂ as a reactive gas, and Ar as an inert gas, a gold color (metallic luster) having a different color from the central portion of the substrate is formed on the outer periphery of the substrate. A brown) film was formed. When these were analyzed, the N atom concentration in the film was higher in the gold film portion than in the center of the substrate.

Therefore, even if the reactive gas is allowed to flow on the surface of the target in the sputter deposition apparatus equipped with a mask as described in Patent Document 1, the above problem cannot be solved.

In addition, when the substrate and the mask are placed in contact with each other, if there is no gap between the substrate and the mask or between the substrate holder and the mask, dust generation is caused by the contact between the substrate and the mask or between the substrate holder and the mask. There is a problem that occurs.

That is, when the substrate is placed on the substrate holder, at least one of the substrate holder and the mask is moved so that the mask and the substrate holder are separated so that the substrate can be placed on the substrate holder. Next, the substrate is placed on the substrate holder, and at least one of the substrate holder and the mask is moved so that the mask and the substrate on the substrate holder are in contact with each other. When the mask is brought into contact with the substrate, the mask and the substrate may rub against each other and dust may be generated. Alternatively, even when the mask and the substrate holder are brought into contact with each other, the mask and the substrate holder may be rubbed to generate dust when the mask and the substrate holder are brought into contact with each other.

The present invention has been made in view of such a problem, and an object of the present invention is to reduce the generation of dust while reducing the generation of dust locally in a reactive sputtering film forming apparatus provided with a mask. It is another object of the present invention to provide a reactive sputtering film forming apparatus in which the atomic concentration of reactive gas in the film is reduced and a film manufacturing method using the same.

In order to achieve such an object, the present invention is provided in a chamber, a substrate holder provided in the chamber and having a substrate setting portion for setting a substrate, and installed in the substrate holder during reactive sputtering. A reactive sputter deposition apparatus comprising: a mask for covering a predetermined region from an edge of a substrate; and a first gas supply port for supplying a gas containing a reactive gas into the chamber, wherein at least the reactivity At the time of sputtering, the mask and the substrate holder are configured so that a space is formed between the mask, the substrate holder, and the substrate placed on the substrate holder, and the substrate is interposed via the space. The apparatus further comprises suppression means for suppressing entry of reactive gas from the periphery of the holder into the substrate installation portion.

Further, the present invention is a mask for covering a predetermined region from the edge of the substrate installed in the substrate holder provided in the reactive sputter deposition apparatus, and forms the labyrinth structure together with the substrate holder. It has at least 1 convex part or a recessed part in at least one part of the area | region of the circumferential direction of the surface which should oppose a holder, It is characterized by the above-mentioned.

The present invention is also a film manufacturing method for manufacturing a film on a substrate, wherein the film is formed on the substrate using the reactive sputtering film forming apparatus of the present invention.

Furthermore, the present invention is a method for forming a film on a substrate by reactive sputtering, wherein the substrate is transported into a chamber and a mask for covering a predetermined area from the edge of the substrate and a substrate for installing the substrate are provided. In a state where a space is formed between the step of placing the substrate on the substrate holder in a state where the holder is separated from the mask, the substrate, and the substrate placed on the substrate holder, A gas containing a reactive gas is supplied into the chamber from a first gas supply port provided in the chamber, and a voltage is applied to a target provided in the chamber to cause plasma discharge in the chamber. And supplying an inert gas from the second gas supply port to the space.

According to the present invention, in the chamber where reactive sputtering is performed, the reactive gas directed to the exhaust port provided in the chamber is outside the substrate holder (on the side facing the center of the substrate, that is, the substrate mounting portion of the substrate holder). The substrate that is in the vicinity of the mask is prevented from entering the gap between the mask, the substrate holder, and the substrate (the gap formed to suppress dust generation) from the side facing the (substrate mounting portion). An increase in the concentration of reactive gas atoms in the film locally at the outer peripheral portion can be reduced. Further, since the gap is provided during reactive sputtering, dust generation due to rubbing between the mask, the substrate and the substrate holder can be suppressed.

1 is a schematic view showing a reactive sputtering film forming apparatus according to an embodiment of the present invention. It is the schematic which shows an example of the reactive sputter film-forming apparatus which has an effect equivalent to the reactive sputter film-forming apparatus shown in FIG. It is the schematic which shows an example of the reactive sputter film-forming apparatus which has an effect equivalent to the reactive sputter film-forming apparatus shown in FIG. It is the schematic which shows the structure of the conventional reactive sputter film-forming apparatus. It is a route diagram of a flow of reactive gas in a conventional reactive sputter film forming apparatus and film forming method. It is a schematic diagram which shows the external appearance of the board | substrate which formed the TiN film into the conventional reactive sputter film-forming apparatus and the film-forming method. It is a figure which shows an example of the labyrinth structure of the mask and substrate holder which concern on one Embodiment of this invention. It is a figure which shows an example of the labyrinth structure of the substrate holder and mask which concern on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings described below, components having the same function are denoted by the same reference numerals, and repeated description thereof is omitted.
In one embodiment of the present invention, in the reactive sputtering, sputter particles are applied to the outer peripheral portion of the substrate placed on the substrate placement portion (substrate placement portion) of the substrate holder or the region where the substrate of the substrate holder is not placed. In order to suppress deposition, a mask is disposed so as to cover a predetermined region from the edge of the substrate (a predetermined region on the outer peripheral portion of the substrate including the edge of the substrate). Thereby, unwanted deposition of sputtered particles on the substrate or substrate holder can be suppressed.

In a film formed on a substrate by a reactive sputtering film forming apparatus using such a mask, there may be a variation in the concentration of reactive gas atoms in the film between the outer peripheral part and the central part of the film. That is, conventionally, the mask and the substrate holder, and the mask and the substrate are separated from each other, and as will be described later, the reactive gas enters from the outside of the mask through the gap formed in the separation portion. The reactive gas atom concentration in the film at the outer periphery of the substrate is locally increased. As a result, the variation occurs.

Therefore, when the mask and the substrate holder are brought into contact with each other and the mask and the substrate are brought into contact with each other, the above-described variation can be reduced as described later. However, when contact is made in this way, rubbing occurs at the contact portion, and dust generation occurs due to the rubbing. That is, since at least a part of the outer peripheral portion of the substrate is covered with a mask, in order to place the substrate on the substrate holder, it is necessary to move the mask in at least one of the upper, lower, left and right directions. The mask is brought into contact with the substrate holder and the substrate. When the mask is disposed so as to cover a part of the outer peripheral portion of the substrate, if the mask and the substrate holder are brought into contact with each other and / or the mask and the substrate are brought into contact with each other, the contact portions are rubbed and dust generation is generated. It will occur.

Therefore, in one embodiment of the present invention, at least during the reactive sputtering process, in order to suppress the generation of the dust, between the mask and the substrate holder, and the substrate placed on the mask and the substrate holder, A gap is provided between the substrate holder and the substrate so that the rubbing does not occur. Therefore, the rubbing can be suppressed during reactive sputtering, and the generation of dust due to the rubbing can be reduced or prevented.

However, if a gap is formed by separating the mask from the substrate holder and the substrate during reactive sputtering, the reactive gas enters from the outside to the inside of the mask as described above, and the film formed in the film A local increase in the concentration of reactive gas atoms will occur.

Therefore, in one embodiment of the present invention, as a suppressing means for suppressing the ingress of reactive gas from the outside of the substrate holder (mask) to the inside (film formation space) of the substrate holder (mask) through the gap, A configuration for relatively increasing the pressure in the gap is provided. As a configuration for relatively increasing the pressure, for example, a gas supply port for supplying an inert gas to the gap is provided, and the inert gas is supplied to the gap from the gas supply port. Just do it. As described above, in the reactive sputter deposition apparatus, the reactive gas can be adjusted by locally adjusting the gap between the substrate and the mask, the gap between the substrate holder and the mask, and the partial pressure of the inert gas in the vicinity thereof. It becomes difficult to flow from the external space (for example, the space outside the mask) through the gap to the internal space (film formation space) on the substrate side, and the local reactive gas atom concentration at the outer peripheral edge of the substrate of the film is reduced. It can improve to become high. In addition, due to the influence of the locally increased inert gas pressure, it is possible to prevent the reactive gas in the film formation space existing inside the mask from entering the gap between the mask and the substrate. As a result, the mask effect can be further enhanced.

Or you may provide the structure (for example, labyrinth structure) for making the conductance of the said gap relatively small as the said suppression means. Thus, when the gap is formed by the labyrinth structure of the substrate holder and the mask, the gap path becomes longer and the conductance of the gap becomes smaller (the conductance is inversely proportional to the length of the path), and the reactive gas. Does not easily flow from the external space through the gap into the internal space on the substrate side. As the suppression means, for example, by combining a configuration for supplying an inert gas into the gap and the labyrinth structure, the above-described operation can be performed more effectively.

In the present invention, it is essential to suppress a local increase in the concentration of reactive gas atoms in a film formed near the mask while suppressing dust generation due to rubbing between the mask, the substrate holder, and the substrate. As long as the reactive gas arriving from the outside to the inside of the mask through the gap formed to suppress the dust generation can be reduced, the suppression means may have any configuration. .

In this specification, the “gap” is a space formed between two target elements (for example, a mask and a substrate holder, a mask and a substrate, etc.) without contact. Point to.

In the present invention, since the suppression means is provided, in order to reduce dust generation caused by rubbing between the mask, the substrate holder, and the substrate, at least during reactive sputtering, between the mask and the substrate holder, and the mask. Even if a gap is provided between the substrate and the substrate, the reactive gas entering from the outside of the substrate holder or the mask through the gap can be reduced. Concentration variation can be suppressed. In addition, since it becomes difficult for the reactive gas to flow into the substrate side through the gap, the reactive gas atom concentration at the outer peripheral edge of the substrate of the film is within the substrate (periphery of the edge), between the substrates (between processing and apparatus) And before and after maintenance), the variation between devices can be improved.

(First embodiment)
Hereinafter, the reactive sputtering film forming apparatus according to the present embodiment will be described with reference to FIGS.
In FIG. 1, the substrate 5 and the mask 8 installed on the substrate holder 6 having the substrate mounting portion, and the substrate holder 6 and the mask 8 are not in contact with each other at least during reactive sputtering. The distance is a few millimeters. A gas supply port 16 facing the gap 15 between the substrate holder 6 and the mask 8 is formed in the substrate holder 6. That is, the gas supply port 16 is arranged to supply the inert gas to the gap 15 and the gap 17 between the substrate 5 and the mask 8. Moreover, as shown in FIG. 1, the gas supply port 10 similar to the conventional technique is also installed. The gas supply port 16 facing the gap 15 can supply a chemically inert gas (inert gas), and the gas supply port 10 reacts with a reactive gas or a chemically inert gas. Sex gas can be supplied.

1, reference numeral 1 denotes a chamber, and a target electrode 3 on which a target 2 is mounted is attached to the chamber 1 via an insulator 4 that electrically insulates the chamber 1 and the target electrode 3. Ti or the like is used as a target. The substrate 5 to be deposited is placed on the substrate holder 6, and they are arranged facing the target 2 in the chamber 1. The shield 7 is a shield that prevents film deposition in the chamber 1. The mask 8 has a shape that covers a predetermined area from the edge of the substrate, such as the outer periphery of the substrate, in order to prevent or reduce film deposition on the outer periphery of the substrate 5. That is, the surface of the mask 8 on the substrate holder side is preferably provided with a step so that the mask covers the surface of the substrate holder 6 on which the substrate 5 is not placed. In this way, by providing a step on the surface of the mask 8 on the substrate holder side, even if the gap 17 is formed between the substrate 5 and the mask 8, the substrate holder 6 does not have the substrate 5 placed thereon. The gap 15 between the mask 8 can be reduced. The gap 15 serves as an entrance for the reactive gas to enter from the outside to the inside of the substrate holder 6 as described above. However, even if the gap 17 is formed between the substrate 5 and the mask 8 as described above, the gap 15 is not provided. 15 can be made smaller, the opening of the entrance can be made smaller, and the amount of reactive gas flowing into the gap 15 from the outside of the substrate holder 6 can be reduced.

Since dust generation may occur when the substrate 5 and the mask 8 come into contact with each other, the mask 8 is arranged so as not to come into contact with the substrate 5 at least during reactive sputtering. The gap between the mask 8 and the substrate 5 is preferably short in order to reduce film deposition (film wraparound) where the mask 8 covers the outer periphery of the substrate, and is preferably about 2 to 3 mm. Further, when the substrate holder 6 and the mask 8 are also brought into contact with each other, dust may be generated. Therefore, they are arranged so as not to contact each other at least during reactive sputtering.

At least one of the substrate holder 6 and the mask 8 is provided with a movable mechanism (not shown) such as an actuator for moving itself. A control device (not shown) is connected to the movable mechanism, and the movable mechanism is driven by the control of the control device, so that at least one of the substrate holder 6 and the mask 8 moves. When taking out the substrate 5 from the substrate holder 6 and installing a new substrate 5 on the substrate holder 6, the control device controls the movable mechanism to widen the distance between the substrate holder 6 and the mask 8. Therefore, the substrate 5 can be easily installed on the substrate holder 6. On the other hand, after the substrate 5 is set on the substrate holder 6, the control device controls the movable mechanism to narrow the distance between the substrate holder 6 and the mask 8, and then performs film formation. In this case, the movable mechanism is controlled so that the distance between the substrate holder 6 and the mask 8 is a predetermined distance set in advance.
Note that the movable mechanism may be manually controlled by the user instead of the control device. That is, when the substrate 5 is placed on the substrate holder 6, the user may manually adjust the movable mechanism so that at least one of the substrate holder 6 and the mask 8 moves.

As described above, in this embodiment, the shape of the mask 8 is set so as to form the

gaps

15 and 17 as shown in FIG. 1, or the movable mechanism is provided on at least one of the mask 8 and the substrate holder 6. Therefore, at least during reactive sputtering, the mask 8 and the substrate holder 6 are configured such that

gaps

15 and 17 are formed between the mask 8 and the substrate holder 6 and the substrate 5.

The inside of the chamber 1 is evacuated to a vacuum by a vacuum pump (not shown) provided at the exhaust port 9. A predetermined gas is supplied into the chamber 1 from a first gas supply port 10 and a second gas supply port 16 provided in the chamber 1. A reactive gas (for example, N ₂ ) or a mixed gas of a chemically inert gas (for example, Ar) and a reactive gas (for example, N ₂ ) is supplied from the first gas supply port 10 to the target 2. The film 7 is supplied to the film formation space 11 surrounded by the shield 7, the mask 8 and the substrate 5. A plurality of second gas supply ports 16 are arranged on the outer periphery of the substrate 5 installed in the substrate holder 6, and only a chemically inert gas (for example, Ar) is supplied from the second gas supply port 16. .

A cathode magnet (not shown) is installed on the back side of the target 2 of the target electrode 3. A DC power source (not shown) is connected to the target electrode 3, and a negative voltage is applied to the target electrode 3 to cause plasma discharge in the film formation space 11. For example, when N ₂ is used as the reactive gas and Ti is used as the target 2, the gas (positive ions) ionized by the plasma discharge is accelerated by the negative voltage to the target electrode 3 to sputter the target 2 and be sputtered. The particles of the target 2 are deposited together with the N ₂ gas activated by the plasma discharge, whereby a TiN film that is a compound of Ti as the target 2 and N _{2 as} the reactive gas is formed on the substrate 5. . An inert gas (for example, Ar) and a part of the reactive gas (for example, N ₂ ) that has not been deposited as a film are discharged through the discharge port 12 to the external space 14 outside the film formation space 11. A part of the gas passes through the gap 13 between the target 2 and the shield 7 and is discharged to the external space 14 outside the film formation space 11. Comparing the conductance of the gas discharge port 12 and the gap 13, the gas discharge port 12 is configured to have a larger conductance than the gap 13, and therefore a portion that has not been deposited as an inert gas and film. Most of the reactive gas is discharged to the external space 14 through the gas discharge port 12. In other words, the inert gas and a part of the reactive gas not deposited as a film are exhausted from the exhaust port 9 toward the exhaust port 9 of the chamber 1 through the gas exhaust port 12 and the gap 13.

Incidentally, the second gas supply port 16 for supplying only a chemically inert gas (inert gas) is provided outside the substrate placement portion of the substrate holder 6. Therefore, an inert gas is supplied from the second gas supply port 16, and a chemically inert gas in the gap 17 between the substrate 5 and the mask 8 and the gap 15 between the substrate holder 6 and the mask 8. By increasing the pressure, the amount of reactive gas re-supplied from the external space 14 through the gap 17 and the gap 15 to the film formation space 14 can be reduced.

That is, the reactive gas that has not contributed to the substrate deposition proceeds from the film formation space 11 to the exhaust port 9 via the discharge port 12 and the gap 13 by driving the vacuum pump. At this time, since the gap 15 is formed outside the substrate holder 6, that is, on the side of the external space 14 facing the film formation space 11, generation of dust is suppressed at least during reactive sputtering. The reactive gas toward the exhaust port 9 flows from the gap 15 into the film formation space 11 through the gap 17. However, in this embodiment, a second gas supply port 16 for supplying a chemically inert gas to the

gaps

15 and 17 is provided, and the inert gas is supplied from the second gas supply port 16. Therefore, the pressure in the

gaps

15 and 17 can be higher than that in the film formation space 11 and the external space 14, and the film formation space 11 of the reactive gas toward the exhaust port 9 through the gap 15 and the gap 17. The inflow to can be suppressed.

Next, a method for forming a film on a substrate by the reactive sputtering film forming apparatus according to the present embodiment will be described.
When the distance between the substrate holder 6 and the mask 8 is such that the substrate 5 cannot be placed on the substrate holder 6, the control device controls at least one of the substrate holder 6 and the mask 8 by controlling the movable mechanism. Thus, the substrate holder 6 and the mask 8 are sufficiently separated. Next, the substrate is transferred by a transfer robot (not shown) as transfer means, and the substrate is placed on the substrate placement portion of the substrate holder 6. Next, the control device controls the movable mechanism to move at least one of the substrate holder 6 and the mask 8, so that a gap 15 is formed between the mask 8 and the substrate holder 6, and between the mask 8 and the substrate 5. A gap 17 is formed between them.

In the present embodiment, at least the

gaps

15 and 17 may be formed at the time of reactive sputtering, and when the substrate 5 is placed on the substrate holder 6, the gap between the mask 8 and the substrate holder 6 and the substrate 5 is sufficient. However, when the

gaps

15 and 17 are appropriate spaces, the substrate holder 6 and the mask 8 need not be moved.

Next, the control device controls a gas supply mechanism (not shown) to supply a reactive gas or a mixed gas of a reactive gas and an inert gas from the first gas supply port 10 into the chamber 1. An inert gas is supplied from the second gas supply port 16 to the

gaps

15 and 17. Further, the control device controls the direct current power source to apply a predetermined negative voltage to the target electrode 3 to cause plasma discharge in the film forming space 11. Thereby, the compound of the sputtered particles sputtered from the target 2 and the reactive gas is formed on the substrate 5.

Hereinafter, the effect of this embodiment will be described by comparing the reactive sputtering film forming apparatus according to this embodiment with an apparatus that does not include the second gas supply port 16.
FIG. 4 shows a reactive sputter deposition apparatus for comparison, which is a conventional reactive sputter deposition apparatus using a mask. The apparatus shown in FIG. 4 has the same configuration as the reactive sputtering film forming apparatus shown in FIG. 1 except that the second gas supply port 16 is not provided. FIG. 5 is an explanatory diagram for explaining the flow of the reactive gas in the reactive sputtering film forming apparatus shown in FIG. FIG. 6 is a schematic view showing an appearance of a substrate on which the film is formed by the reactive sputtering film forming apparatus shown in FIG.

Most of the reactive gas supplied to the film formation space 11 via the first gas supply port 10 is consumed by depositing as a film on the substrate 5, the shield 7, and the mask 8, but part of the reactive gas is described above. Is discharged to the external space 14 outside the film formation space 11 through the discharge port 12. On the other hand, the substrate 5 and the mask 8 and the substrate holder 6 and the mask 8 are not contacted as described above. That is, the external space 14 and the film formation space 11 are connected not only through the discharge port 12 and the gap 13 between the target 2 and the shield 7 but also through the gap 15 between the substrate holder 6 and the mask 8. ing. Therefore, there are a small amount of inert gas and reactive gas that go back and forth between the external space 14 and the film formation space 11 through the gap 15. FIG. 5 shows a reactive gas path in the conventional reactive sputtering film forming apparatus shown in FIG. As shown in FIG. 5, the reactive gas supplied from the gas supply port 10 to the film formation space 11 is discharged to the external space 14 through the discharge port 12 and then to the film formation space 11 through the gap 15. Some are resupplied. The reactive gas re-supplied from the external space 14 through the gap 15 to the film formation space 11 is activated by the plasma and easily deposits as a film on the end of the substrate 5 near the gap 15. Therefore, it is considered that the reactive gas atom concentration of the film deposited on the edge of the substrate 5 is higher than that of the film deposited on other parts of the substrate 5.

A film having a high concentration of reactive gas atoms deposited on the edge of the substrate 5 will be described with reference to FIG. FIG. 6 is a schematic diagram of the appearance of the substrate 5 on which Ti 2 is formed using Ti as the target 2 and Ar and N ₂ as the chemically inert gas and the reactive gas, respectively. As shown in FIG. 6, a region 101 where no TiN is deposited is formed on the periphery of the substrate 5 covered with the mask 8. Most of the region where TiN formed on the substrate 5 indicated by reference numeral 102 in FIG. 6 is deposited has the same color as Ti as the target 2. On the other hand, the boundary between the region 101 where TiN is not deposited and the region (film) 102 having the same color as Ti was a gold (brown with a metallic luster) film 103. The film 102 having the same color as Ti in the region b shown in FIG. 6 and the N atom concentration (reactive gas atom concentration) of the gold film 103 in the region B in the vicinity of the region b are represented by an X-ray microanalyzer (EPMA: Electron Probe Micro Analyzer), the N atom concentration of the film 102 having the same color as Ti is 31 at. %, Whereas the golden film 103 is 45 at. %Met.

The reason why the N atom concentration in the film of the gold film 103 is high is that, as described above, there is N ₂ gas re-supplied from the external space 14 through the gap 15 to the film forming space 11. In consideration, the distance between the substrate holder 6 and the mask 8 (the size of the gap 15) was changed, and the conductance of the gap 15, that is, the ease of passing the N ₂ gas that is a reactive gas in the gap 15 was tried. . As the distance between the substrate holder 6 and the mask 8 increases, the area of the golden film 103 increases, and when the substrate holder 6 and the mask 8 are brought into contact with each other in order to eliminate the gap 15, The gold film 103 disappeared in the vicinity of the portion where the mask 8 was brought into contact. That is, as described above, the N ₂ gas re-supplied from the external space 14 through the gap 15 to the film formation space 11 exists, so that a film having a high N atom concentration is deposited on the edge of the substrate 5. Since the amount of N ₂ gas supplied again depends on the conductance of the gap 15, it can be said that the area of the golden film 103 having a high N atom concentration is increased as the gap 15 is increased.

On the other hand, in a film forming apparatus for a large area substrate such as a display, the substrate holder 6 and the mask 8 are also sized according to the substrate 5. Therefore, it is difficult to make the gap 17 between the substrate 5 and the mask 8 and the gap 15 between the substrate holder 6 and the mask 8 uniform in the circumferential direction of the substrate 5. The nonuniformity of the gap 15 in the circumferential direction of the substrate 5 makes the amount of the reactive gas re-supplied from the gap 15 to the film forming space 11 nonuniform in the circumferential direction of the substrate 5. That is, not only a film having a high N atom concentration is deposited on the edge of the substrate 5, but also the reactive gas atom concentration of the film deposited on the edge of the substrate 5 is different in the circumferential direction of the substrate 5. The amount (deposition area) of the film having a high reactive gas atom concentration to be deposited differs in the circumferential direction of the substrate 5.

In order to remove the deposited film, the mask 8 needs to be replaced periodically. The dimensional error and the mounting error of the mask 8 are the difference in the gap 15 before and after the replacement of the mask 8. That is, before and after the replacement of the mask 8, a film having a high reactive gas atom concentration at the edge of the substrate 5 is likely to have a different reactive gas atom concentration. The same applies between devices. In order to avoid such a situation, the dimensional error and the mounting error of the mask 8 must be reduced. Therefore, the mask 8 is likely to be expensive, and it takes time to make adjustments necessary for mounting when replacing the mask 8.

In the present embodiment, as shown in FIG. 1, by supplying only the inert gas from the second gas supply port 16, the inert gas flows in the direction of the solid line arrow P <b> 1 (from the second gas supply port 16. In the direction toward the external space 14). Therefore, it is possible to prevent or reduce the re-supply of the reactive gas from the external space 14 (arrow Q in FIG. 4).

Therefore, in the present embodiment, the reactive gas atom concentration of the film deposited on the edge of the substrate is set to that of the film deposited on the other part of the substrate without bringing the substrate and the mask into contact with the substrate holder and the mask. As a result, the amount of the reactive gas atoms deposited on the edge of the substrate can be reduced (the deposition area can be reduced) compared to that of the film deposited on other parts of the substrate.

Further, the inert gas supplied to the

gaps

15 and 17 from the second gas supply port 16 also proceeds in the arrow direction P2 of FIG. 1 (the direction from the second gas supply port 16 toward the film formation space 11). . Therefore, even if the mask 8 and the substrate 5 are separated from each other and the gap 17 is formed during the reactive sputtering, the film formation space is caused by the outflow of the inert gas in the arrow direction P2 from the gap 17 toward the film formation space 11. Reactive gas entering the gap 17 from 11 can be suppressed. Therefore, in order to suppress dust generation, even if the mask 8 and the substrate 5 are separated from each other, the reactive gas existing in the film formation space 11 penetrates into a region covered with the mask 8 where deposition is not desired. Can be suppressed, and a further mask effect can be realized. That is, even if the mask 8 and the substrate are separated from each other, a good mask effect can be obtained, so that it is possible to suppress film deposition in a region where deposition is not desired while suppressing dust generation.

Furthermore, in this embodiment, even if the sizes of the

gaps

15 and 17 are different in the circumferential direction of the substrate 5, the gas is supplied from the second gas supply port 16 regardless of the size of the

gaps

15 and 17. By the inert gas proceeding in the arrow direction P1, the invasion of the reactive gas from the external space 14 to the film forming space 11 via the

gaps

15 and 17 can be reduced. Therefore, even if the substrate is enlarged, the reactive sputter deposition apparatus with excellent productivity that can improve the uniformity of the reactive gas atomic concentration of the film deposited on the edge of the substrate in the circumferential direction of the substrate. Can be provided.

In the above embodiment, the example in which the second gas supply port 16 is provided in the substrate holder 6 has been described. However, the second gas supply port is provided in the mask 8 and the mask 8 and the substrate holder as shown in FIG. Even if it is provided facing the gap 17 of 6, the same effect can be obtained. Further, as shown in FIG. 3, it may be provided in the space 17 between the mask 8 and the substrate holder 6. That is, as long as the inert gas can be supplied to the

gaps

15 and 17, the arrangement position of the second gas supply port 16 for supplying the inert gas may be any.

(Examples and comparative examples)
In this embodiment, the substrate 5 is a glass substrate for LCD application having a size of 550 mm × 650 mm × thickness 0.7 mm. Ar, which is a chemically inert gas, was supplied at 144 sccm from a gas supply port 16 provided facing the gap 15, and N _{2 as} a reactive gas was supplied at 256 sccm from the gas supply port 10. By applying 35 Kw from a DC power source (not shown) for 60 seconds, a TiN film having an average film thickness of 170 nm was formed on the substrate 5.

Further, in order to compare the reactive sputtering film forming apparatus and reactive sputtering film forming method for comparison with the present embodiment with this example, there is no gas supply port 16 facing the gap 15, FIG. In the reactive sputtering film forming apparatus (conventional apparatus, which is a comparative example), film formation was performed by supplying 144 sccm of Ar gas and 256 sccm of N ₂ gas from the gas supply port 10.

As shown in the schematic diagram of FIG. 6, the edge of the substrate 5 covered with the mask 8 was a region 101 where no TiN film was deposited. Most of the region of the substrate 5 on which the TiN film was deposited indicated by reference numeral 102 in FIG. 6 was the same color as Ti as the target 2. On the other hand, the boundary between the region 101 where no TiN film is deposited and the film 102 having the same color as the Ti is the gold film 103. By measuring the N atom concentration and the width of the gold film 103 shown in FIG. 6 of the substrate 5 formed by the apparatus of the present example and the prior art apparatus (comparative example) of FIG. The effect was confirmed. The locations where the N atom concentration was measured are the center in the width direction of the gold film 103, which are points A to C shown in FIG. 6, and a to c of the film 102 of the same color as Ti.

The results obtained will be described with reference to Tables 1 and 2.

Table 1 shows the N atom concentration of the TiN film formed using the comparative example and this example. The N atom concentration in the gold film 103 in the comparative example is 41 to 45 at. %, While that of the TiN film in this example is 32 to 35 at. %Met. The N atom concentration in the film 102 of the same color as Ti in the comparative example is 28 to 31 at. % Of the TiN film in this example is 27 to 29 at. The TiN film formed in this example was able to bring the N atom concentration in the gold film 103 close to that of the film 102 having the same color as Ti. Table 2 shows the width of the gold film 103 of the TiN film formed using the comparative example and this example. In the comparative example, it was 4 to 8 millimeters, whereas in the present example, it was 1 to 3 millimeters, and the amount of the golden film 103 could be reduced (deposition area was reduced).

(Second Embodiment)
In the first embodiment, a configuration in which the pressures of the

gaps

15 and 17 are relatively increased, that is, a configuration in which a second gas supply port 16 is provided and an inert gas is supplied from the second gas supply port 16 is provided. Thus, the reactive gas in the external space 14 (reactive gas toward the exhaust port 9) is prevented from passing through the

gaps

15 and 17 and entering the film forming space 11.

In the present embodiment, a labyrinth structure is provided at least in the gap 15, and the labyrinth structure prevents the reactive gas from passing from the external space 14 to the film formation space 11 side via the

gaps

15 and 17.

In the present specification, the “labyrinth structure” refers to a structure that reduces the conductance of the gas passing through the labyrinth structure. Thus, for example, in the labyrinth structure, a member in which at least one concave portion is formed and a member in which at least one convex portion are formed are fitted in a non-contact manner to form a small passage between them. Structure. Alternatively, the first member on which at least one convex portion is formed and the second member on which at least one convex portion are formed are staggered so that the respective convex portions are not in contact with each other, and one convex portion is the other. It may be a structure that is arranged so as to be non-contact with the member. In any case, the labyrinth structure according to the present embodiment is any structure as long as the conductance with respect to the gas passing through the labyrinth structure itself can be reduced by a combination of convex portions and concave portions formed on two predetermined members. There may be.

In the present embodiment, the convex portion and the concave portion are formed on a mask or a substrate holder. When the mask is configured to form a closed loop at the outer peripheral portion of the substrate holder, the convex portion and the concave portion are arranged in a predetermined region of the mask and the substrate holder in consideration of suppressing the inflow of the reactive gas. It is preferable to form so as to make a round in the direction. For example, in the case of forming the recess, a groove having a predetermined width may be formed in the circumferential direction so as to be a closed loop in the region of the mask or the substrate holder having the labyrinth structure. Similarly, when forming a convex part, what is necessary is just to form a projection part so that it may become a closed loop in the circumferential direction in the area | region used as the labyrinth structure of a mask or a substrate holder.

Further, when the mask is configured not to form a closed loop at the outer peripheral portion of the substrate holder (that is, when only a part of the outer peripheral portion of the substrate is masked), the concave portion and the convex portion are end to end in the circumferential direction of the mask. It is preferable to form up to.

However, what is important in the present embodiment is that the labyrinth structure suppresses the reactive gas that enters the film formation space 11 from the external space 14 through the

gaps

15 and 17. Therefore, if the intrusion of the reactive gas from the external space 14 can be reduced, the technical object of the present embodiment can be achieved. Therefore, it is not an essential condition to form the labyrinth structure in the entire circumferential direction of the mask and the substrate holder. For example, when the reactive gas enters from a certain direction outside the substrate holder 6 and the mask 8 due to the structure of the apparatus, the labyrinth structure may be provided only in that direction. Alternatively, when it is sufficient to cut the ingress of the reactive gas from the external space 14 by a predetermined ratio, the reactivity of the predetermined ratio is not provided without providing a labyrinth structure in the entire circumferential direction of the mask 8 and the substrate holder 6. A labyrinth structure may be provided to such an extent that gas entry can be cut. Furthermore, a labyrinth structure may be provided in an intermittent manner in the circumferential direction of the mask 8 and the substrate holder 6.

That is, in the present embodiment, at least one concave portion or convex portion for forming a labyrinth structure is formed in at least a part of a region (surface to be opposed to the substrate holder 6) along the circumferential direction of the mask 8, The substrate holder 6 may be formed with a recess or projection in at least a part of the region along the circumferential direction of the substrate holder so that the labyrinth structure is formed together with the recess or projection formed in the mask. Thus, by providing the labyrinth structure in at least a part of the circumferential direction of the mask 8 and the substrate holder 6, the reactive gas entering from the external space 14 through the

gaps

15 and 17 can be reduced.

FIG. 7 is a view for explaining a labyrinth structure as a suppressing means according to the present embodiment. FIG. 7 shows an example in which the gap 15 between the substrate holder 6 and the mask 8 is formed with these labyrinth structures.
In FIG. 7, a plurality of convex portions 22 for forming a labyrinth structure are formed on the outer side of the substrate mounting portion on which the substrate 5 is mounted on the surface of the substrate holder 6 facing the mask 8. Each of these convex portions 22 is provided so as to form a closed loop in the circumferential direction of the substrate holder 6. In addition, a plurality of grooves 21 as concave portions for forming a labyrinth structure are formed on the surface of the mask 8 facing the substrate holder 6. Each of these grooves 21 is also provided so as to form a closed loop in the circumferential direction of the mask 8. In the present embodiment, since the groove 21 and the convex portion 22 are fitted in a non-contact manner to form a labyrinth structure, the width of the groove 21 is larger than the width of the convex portion 22.

In this embodiment, a labyrinth structure is formed by the groove 21 and the convex portion 22 during reactive sputtering. Therefore, the movable mechanism is controlled by the control device or manually to adjust the position of at least one of the mask 8 and the substrate holder 6 so that the convex portion 22 fits in the groove 21 in a non-contact manner. Thereby, a non-contact space with a small conductance is formed between the groove 21 and the convex portion 22. Since the conductance is inversely proportional to the length of the path, the path of the gap 15 becomes longer by forming the gap 15 with the labyrinth structure as shown in FIG. Therefore, the conductance of the gap 15 can be reduced. As described above, since the mask 8 and the substrate holder 6 are not in contact with each other, dust generation can be suppressed, and furthermore, the conductance in the non-contact space is small, so that the reactive gas entering from the gap 15 can be suppressed. .

(Third embodiment)
In the present embodiment, the first embodiment and the second embodiment are combined. FIG. 8 is a view for explaining the suppression means according to the present embodiment.
In FIG. 8, at least one of the convex portions 22 provided in the substrate holder 6 shown in FIG. 7 is used as the second gas supply port 16 described in the first embodiment. As described in the second embodiment, in this embodiment, the conductance of the gap 15 can be reduced by the labyrinth structure. By flowing an inert gas from the second gas supply port 16 into the gap 15 having such a small conductance, it becomes easier to locally adjust the partial pressure of the inert gas in the gap 15 to be more reactive. The above-described operation of making it difficult for the gas to flow into the film formation space 11 from the external space 14 through the gap 15 can be performed more effectively.

Claims

A chamber;
A substrate holder provided in the chamber and having a substrate placement portion for placing a substrate;
A mask for covering a predetermined region from the edge of the substrate placed on the substrate holder during reactive sputtering;
A first gas supply port for supplying a gas containing a reactive gas into the chamber;
At least during the reactive sputtering, the mask and the substrate holder are configured such that a space is formed between the mask and the substrate holder and the substrate placed on the substrate holder.
A reactive sputter deposition apparatus, further comprising suppression means for suppressing entry of a reactive gas from the periphery of the substrate holder through the space into the substrate installation portion.
The suppression means is
A second gas supply port for supplying an inert gas to the space;
The reactive sputter deposition apparatus according to claim 1, wherein the inert gas is supplied from the second gas supply port during the reactive sputtering.
The suppression means is
The reactive sputter deposition apparatus according to claim 1, comprising a labyrinth structure formed in a part of the space by the substrate holder and the mask.
A plurality of convex portions or concave portions are formed on at least part of the circumferential direction of the surface of the mask facing the substrate holder,
The substrate holder is at least a part of the circumferential direction of the surface facing the mask, and a plurality of convex portions or concave portions are formed outside the substrate installation portion,
The labyrinth structure is formed by combining a plurality of convex portions or concave portions formed on the mask and a plurality of convex portions or concave portions formed on the substrate holder in a non-contact manner. The reactive sputter film forming apparatus according to claim 3.
A mask for covering a predetermined area from the edge of the substrate installed in the substrate holder provided in the reactive sputter deposition apparatus,
A mask having at least one convex portion or concave portion in at least a part of a circumferential region of a surface to be opposed to the substrate holder so as to form a labyrinth structure together with the substrate holder.
A film production method for producing a film on a substrate, wherein the film is formed on the substrate using the reactive sputtering film forming apparatus according to claim 1.
A method of forming a film on a substrate by reactive sputtering,
Placing the substrate on the substrate holder in a state where the substrate is transported into the chamber and a mask covering a predetermined region from the edge of the substrate and a substrate holder for installing the substrate are separated from each other;
Reactive gas is introduced into the chamber from a first gas supply port provided in the chamber in a state where a space is formed between the mask and the substrate holder and the substrate placed on the substrate holder. Supplying a gas containing, applying a voltage to a target provided in the chamber to cause a plasma discharge in the chamber, and supplying an inert gas from the second gas supply port to the space. A method characterized by comprising.
The method according to claim 7, further comprising the step of forming the space by moving at least one of the substrate holder and the mask before the supplying step.