JP2011032550A - Sputtering apparatus, and method of producing element for display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sputtering apparatus capable of reducing troubles such as abnormal electric discharge or peeling of a deposited film due to a shield used for the apparatus. <P>SOLUTION: The sputtering apparatus includes an exhaustable sputtering chamber, a plurality of support bodies which are provided in the sputtering chamber for mounting a target and are each rotatable, and a plurality of cathodes which are provided on a plurality of planes of the respective support bodies spacing from each other. The apparatus positions the target mounted on the target-mounting surface of the cathode to deposit a film on the substrate by rotating every support bodies depending on the position of a substrate surface to be deposited which is positioned in the sputtering chamber. The apparatus has a constitution such that the shield thereof is parallel to the surface of the target for plasma-cleaning the target of the support body. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention is a sputtering apparatus, in particular, can be formed by simultaneous sputtering of a plurality of targets on a single substrate, and further by a structure capable of plasma cleaning of the target in a direction other than the film formation surface, thereby saving space, The present invention relates to a sputtering apparatus that achieves high throughput and cost reduction, and a method for manufacturing a display element using the sputtering apparatus.

  Conventionally, in a general sputtering apparatus, when cleaning a target, the target is directed in a direction not facing the substrate, and discharge is performed between the shield surrounding the part of the cathode with the target and the target. The cleaning method was performed.

  FIG. 4 is an example of a schematic view for explaining a main part in the sputtering chamber 1 of the conventional sputtering apparatus, and is a plan view seen from above parallel to the side surface of the substrate 12. The conventional example shown in FIG. 4 is an example of double-sided film formation. In the sputtering chamber 1, six supports 20, 21, 22, 20 ′, 21 ′, and 22 ′ on which three targets can be mounted are provided. I have.

Reference numeral 10 denotes a tray for holding the substrate 12, and reference numeral 11 denotes a gate valve. As is well known, the substrate 12 passes through the sputtering chamber 1 and is carried in and out from the direction of arrow a.

  For example, the supports 20, 21, and 22 are supports that can rotate about the central axes C20, C21, and C22, respectively. The respective supports are provided in the sputtering chamber 1 so as to be spaced apart from each other and to be provided with respective target mounting surfaces facing the film formation surface of the substrate 12 mounted on the tray 10. Each of the supports 20, 21, and 22 is provided with three cathodes on one support. The three cathodes are provided apart from each other and each have a target mounting surface. This configuration is the same for the supports 20 ′, 21 ′, and 22 ′.

The target positioning mechanism (not shown) rotates each of the supports 20, 21, and 22 with the targets 40, 41, and 42 mounted on the target mounting surface, respectively, and one of the multiple targets that one support has It is possible to position the target for each support to the film formation position facing the film formation surface of the substrate 12.

Thus, according to the configuration of the conventional sputtering apparatus, each support 20, 21, 22 is provided to face the film-forming surface of the substrate 12, and the same number of cathodes 30, 31 and 32 are provided. Different types of targets 40, 41, and 42 can be mounted on a plurality of cathode target mounting surfaces of one support. When a plurality of types of targets are mounted on each support, the same number of each type is mounted, preferably in the same order.

In addition, this conventional sputtering apparatus is provided in the sputtering chamber 1 and surrounds the support over a part of the periphery of the supports 20, 21, and 22 and faces the substrate 12 during film formation. , Shields 50, 51 and 52 (shields 50 ', 51' and 52 'for supports 20', 21 'and 22') are provided for each support.

And since the support itself is configured to be rotatable, by providing such a shield, the shield 50, against the target 40, 41, 42 on the side that is not actually opposed to the substrate 12, In the back surface discharge space 13 having a circular arc shape between 51 and 52 and the target, preliminary plasma cleaning (also referred to as aging or pre-sputtering, hereinafter also referred to as cleaning) of the target surface is appropriately performed to obtain a non-erosion region. A cleaning mechanism capable of flattening the substrate, removing splats, for example, removing a nitride film formed on the target surface in the case of a Ti target or the like.

JP 2003-147519 JP Japanese Unexamined Patent Publication No. 7-28098

  However, the cleaning mechanism of this conventional sputtering apparatus is such that the distance between the shield and the target is not constant for each target location because the back surface discharge space 13 shown in FIG. However, when high power is applied at once, abnormal discharge is likely to occur. Therefore, in order to achieve the target integrated power value suitable for cleaning, the discharge power must be increased stepwise, unnecessary time and power consumption, consumption not used for target production, etc. There was a drop in productivity.

  In the cleaning mechanism of this conventional sputtering apparatus, since the back surface discharge space 13 is an arc shape, the distance between the shield and the target is not constant for each target location, and the shield end portion between the shield and the target The heat generated by the discharge is more likely to be generated at the portion where the distance of is shorter. As a result, local deformation of the shield is likely to occur, the life of the shield is shortened, the number of times that the shield must be maintained and replaced with a new shield is increased, and productivity is reduced.

  Further, the cleaning mechanism of this conventional sputtering apparatus is such that the distance between the shield and the target is not constant for each location of the target because the back surface discharge space 13 is an arc shape. The film thickness of the adhesion film is thicker at a portion where the distance between the shield and the target is shorter, and is thinner at a portion where the distance between the shield and the target is longer.

If the thickness of the film attached to the shield exceeds a certain level, the film attached to the shield may peel off, causing abnormal discharge, etc., and the shield may be deformed due to stress, etc. Before the anomaly occurs, it must be replaced with a new shield. At this time, even if the distance between the shield and the target is longer, the thickness of the adhesion film is thinner, and the possibility of occurrence of the above abnormality is not seen, the distance between the shield and the target is shorter, When the film thickness of the adhesion film on the shield becomes thicker and the possibility of the occurrence is seen, the shield needs to be replaced, resulting in a decrease in productivity.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sputtering apparatus having a cleaning mechanism with higher productivity by changing the shield structure in the target cleaning mechanism.

In order to solve the above-described problems, a sputtering apparatus according to the present application includes a sputtering chamber that can be evacuated, a plurality of rotatable supports for mounting a target, each of which is provided in the sputtering chamber, A plurality of cathodes provided on a plurality of surfaces so as to be spaced apart from each other, and the cathodes are rotated for each of a plurality of supports in accordance with positions of film formation surfaces of a substrate positioned in a sputtering chamber. In a sputtering apparatus for performing film formation on a substrate by positioning the target mounted on the target mounting surface of
In order to perform plasma cleaning on the target of the support, a structure having a shield parallel to the surface of the target is used.

  According to the sputtering apparatus of the present invention, since the film is uniformly attached to the shield, it is stabilized without causing abnormal discharge even when high power is applied as appropriate, and the shield replacement cycle is increased. Without deteriorating the properties, preliminary cleaning of the target surface before sputtering on the substrate, planarization of the non-erosion region, removal of splats, and the like can be performed.

FIG. 5 is a schematic plan view of a main part for explaining a sputtering apparatus according to the present invention, showing a configuration example in which a film is simultaneously formed on one substrate using three targets. It is a schematic plan view of a principal part for explaining still another configuration example of the sputtering apparatus of the present invention, and is a diagram showing a configuration example in which the present invention is applied to a double-sided film forming apparatus. It is a schematic explanatory drawing used for description of the cleaning apparatus with which the sputtering apparatus which is the principal part of this invention is equipped. It is a schematic top view of the principal part which shows description of the structural example of the conventional sputtering apparatus.

  Hereinafter, embodiments of the sputtering apparatus according to the present invention will be described with reference to the drawings. In these drawings, the shape, size, and arrangement relationship of each constituent element are outlined to the extent that the present invention can be understood. It is only shown in In the following, preferred configuration examples of the present invention will be described. However, the present invention is not limited to the preferred examples of the present invention, and many modifications and changes can be made without departing from the gist of the present invention. .

  FIG. 1 is a plan view mainly schematically showing a substrate, a support, a target, and a shield, which are main constituent elements in the sputtering chamber of the sputtering apparatus according to the present invention. In the configuration example shown in FIG. 1, a single substrate 12 is mounted on the substrate holder 17. The substrate 12 is erected in a direction perpendicular to the paper surface of the drawing and is held by a substrate holder 17. The film formation surface 12a of the substrate is usually a flat surface.

The shape of the substrate 12 is a rectangular parallel flat plate. The substrate holder 15 is loaded into the sputtering chamber 1 through the gate valve 11 and positioned from the direction of arrow a with the substrate 12 mounted.
A plurality of support bodies 25, 26, and 27 as an example, for supporting a target, are installed facing the film formation surface 12a of the substrate 12. In this configuration example, the supports 25, 26, and 27 are made into a support having a quadrangular cross section, for example, a rectangular body whose opposing surface is a parallel plane. Therefore, the cross section is rectangular as an example.

These supports 25, 26, and 27 are formed so that their central axes rotate as rotation axes C25, C26, and C27, and are stopped at appropriate rotation positions and positioned at the stop positions.
The surfaces 25a, 26a, 27a of the supports 25, 26, 27 on the side facing the film forming surface 12a and the opposing surfaces 25b, 26b, 27b on the opposite side constitute the target mounting surface. In this case, cathodes 35a, 36a, 37a, 35b, 36b and 37b are individually provided on the surfaces of the supports 25, 26 and 27 themselves, and the outer surfaces of these cathodes are used as target mounting surfaces 25a, 26a, 27a and 25b. 26b and 27b. In this configuration example, the support and the cathode are separated.

The rotation axes C25, C26, and C27 are parallel to the film formation surface, and the rotation axes are parallel to each other. The supports 25, 26, and 27 have a structure that can rotate in both forward and reverse directions about the rotation axes C25, C26, and C27.
The rotation axis C26 of the support body 26 on the center side is aligned with the center of the substrate 12, and the rotation axes C25 and C27 of the support bodies 25 and 27 on both sides thereof are positioned at an equal distance from the rotation axis C26. Yes. Further, the rotation axes C25 and C27 are positioned so as to have an optimum positional relationship between the film formation surface, that is, the substrate surface, and between the mutual targets.

  Corresponding targets are mounted on the respective target mounting surfaces. Among these targets, the targets mounted on one of the cathodes 35a, 36a, and 37a are the same type of targets. The targets mounted on the other cathodes 35b, 36b, and 37b may be different types or the same type as the one target, but are the same type of targets.

  The support 26 on the center side is positioned so that the target mounting surfaces 26a and 26b, that is, the sputtering target surfaces of the targets mounted on the target mounting surfaces are parallel to the film forming surface 12a. Similarly, the target mounting surfaces 25a, 25b and 27a, 27b of the supports 25 and 27 on the peripheral sides on both sides with the support 26 on the center side as the center, that is, the sputtering surface of the target mounted on these target mounting surfaces Is positioned so as to face the film formation surface 12a.

  In this case, for example, the intersecting angles of the extension lines of the target mounting surfaces 25a and 27a of the supports 25 and 27 on the peripheral side and the extension line of the film formation surface 12a are equal to each other at an angle α (0 ° <α <90 ° ). In this way, the target mounting surfaces 35a, 35b and 37a, 37b on the peripheral side become closer to the film formation surface 12a as they move away from the target mounting surfaces 36a, 36b on the central side. It is inclined with respect to the mounting surface. As a result, the sputtering target surface and the film formation surface of the target on the peripheral side are inclined (intersected) at an angle α.

  A back surface discharge space 13 for cleaning the target is mounted on the side opposite to the film formation surface 12a with respect to the supports 25, 26, and 27. This back surface discharge space 13 is formed on the film formation surface with respect to the supports 25, 26, 27 when the target mounting surfaces 25a, 26a, 27a or 25b, 26b, 27b are parallel to the film formation surface 12a. Shields 55, 56, and 57 are mounted so that the distance from the target mounting surface facing the side opposite to 12a is constant. Here, for example, the distance β can be set to a distance smaller than 500 mm.

  On the shields 55, 56, 57, cooling mechanisms 14, 15, 16 are mounted in order to suppress the temperature rise of the shield due to discharge. The cooling mechanisms 14, 15, and 16 are mechanisms that allow a cooling medium to flow.

Such a cleaning mechanism with a fixed distance β between the support 25, 26, 27 and the target mounting surface facing the side opposite to the film forming surface 12a with respect to the support 25, 26, 27 is used for cleaning. Even when high power was applied at once, the occurrence of abnormal discharge could be reduced.
In addition, since the cleaning mechanism with a constant distance β between the support 25, 26, 27 and the target mounting surface facing the side opposite to the film forming surface 12a is mounted, the temperature received by the entire shield is reduced. It became constant, the deformation of the shield hardly occurred, and the shield had a long life.

Furthermore, a film that adheres to the entire shield is mounted by mounting a cleaning mechanism with a constant distance β between the support 25, 26, 27 and the target mounting surface facing the side opposite to the film forming surface 12a. The distribution of the laser became constant, and the life of the shield became longer.
Since the cooling mechanisms 14, 15, and 16 are mounted on the shield, the temperature rise due to the discharge of the shields 55, 56, and 57 is suppressed, and the life of the shield against local thermal deformation can be extended.

  FIG. 2 is a schematic plan view for explaining a configuration example in which the present invention is applied to a double-sided film forming apparatus. In this case, the substrates 12 and 12 ′ are mounted on both sides of the tray 10, and a film is formed on both the substrates 12 and 12 ′.

In this configuration example, in addition to the supports shown in FIG. 1, in addition to these, another support is provided symmetrically with respect to the tray 10 and on the opposite side of the tray 10.
Another difference from FIG. 1 is that three targets are provided on one support. These symmetrically newly provided supports and other necessary constituent elements are indicated with a `. Since these additional supports and the like have the same configuration and operation (or function) as the support and the like described with reference to FIG. 1, their detailed description is omitted.

  In the configuration example shown in FIG. 2, three supports having the same configuration are provided on each side of the tray 10. Supports 20 and 20`, 21 and 21` and 22 and 22` correspond to 25, 26 and 27 in FIG. 1, respectively. Each of these supports has a substantially hexagonal column shape, but every other side has a large side surface, and a cathode is provided on each side surface. Each support rotates (rotates) in the forward and reverse directions around the central axes C20, C21, C22, C20 ′, C21 ′, and C22 ′, and stops at an appropriate rotational position. It is formed so that the target can be positioned at a location. The central axis of each support is parallel to the film formation surface and parallel to the respective central axes, like the central axes of the supports 25, 26 and 27 in FIG.

  Of these six supports, the support 20 and 21 on the center side and one peripheral side will be described as representatives, and the structure and operation of the remaining supports are the same as either of the supports 20 and 21. Since there is, overlapping description is omitted.

  The rotation axes of the supports 20 and 21 are C20 and C21, and the cathodes provided on the three side surfaces of the support are 30a, 30b, 30c and 31a, 31b, 31c. Targets 40a, 40b, 40c, 41a, 41b and 41c are mounted on the target mounting surfaces 20a, 20b, 20c, 21a, 21b and 21c of the respective cathodes. The three targets for one support may be the same type of target or different types of targets. Between the supports, the same type of target is mounted at the same order position. Accordingly, the same type of target simultaneously faces the substrates 12 and 12 '.

  In the configuration example shown in FIG. 2, film formation is performed by rotating each support and positioning first targets of the same type opposite to each other. In this manner, films of three different components can be formed on a single substrate 12 in the same sputtering chamber.

  In the configuration example shown in FIG. 2, as in the case described with reference to FIG. 1, the target sputtering surface facing the film formation surface of the substrate during film formation, and thus the target mounting surface of the support is on the center side. In the case of a certain support 21, it is parallel to the film formation surface 12 a, while the support 20 on the peripheral side is inclined at an angle α with respect to the film formation surface 12 a. However, the sputtering target surfaces of all targets facing the substrate at the time of film formation may be parallel to the substrate surface.

  Also in the configuration example shown in FIG. 2, as in FIG. 1, the distance β between the support and the target mounting surface facing the side parallel to and opposite to the film-forming surface 12a is constant for each support. Such shields 50, 51, 52, 50`, 51`, 52` are provided, respectively. These shields are provided so as to substantially cover the cathode and the target in the vertical direction along the central axis direction of each support. The shields 50, 51, 52, 50`, 51`, 52` are provided on the back side of the support (in the direction opposite to the film formation surface 12a) so as not to hinder the rotation of the support. It has been.

This shield is provided with a cleaning mechanism in each shield. By providing this cleaning mechanism, it is possible to perform preliminary cleaning on each support without affecting other supports and the substrate.
This cleaning mechanism has a dedicated direct current or high frequency power source at least for each cathode on which each target is mounted. Further, when the cathode faces in the direction opposite to the cleaning mechanism, the distance between the cathode mounting surface and the cleaning mechanism is constant, and a structure is provided to suppress abnormal discharge and shield deformation. The cleaning mechanism is provided with a cooling mechanism that suppresses the temperature rise of the shield. These cleaning devices may have any suitable configuration depending on the design.

  FIG. 3 is a schematic diagram for explaining one configuration example of the cleaning mechanism. Each cathode 30a, 30b, 30C is provided with a target mounting surface 20a, 20b, 20C and a target 40a, 40b, 40C disposed thereon, and a direct current or high frequency power source 15 capable of applying individual power to each of them. deep. A cooling mechanism 14 for cooling the shield is provided on the back surface of the shield 50. Further, it is desirable to provide a shielding mechanism in order to avoid the target particles from adhering to other parts during cleaning.

Next, as an example of an actual display element manufacturing method, a manufacturing process of a liquid crystal panel using the sputtering apparatus of the present invention will be described.
The liquid crystal panel manufacturing process includes an array manufacturing process, a BM (black matrix) manufacturing process, and the like. A sputtering apparatus is mainly used in the following processes a, d, and e among the array manufacturing processes.
Here, the array manufacturing process includes, for example, transistors and wirings on a glass substrate. Specifically, various thin film formation, cleaning, photoresist coating, pattern exposure, development, etching, resist peeling, and inspection are performed. It consists of each process.

In this, film formation is performed in the following order: a → b → c → d → e → f.
a. Gate electrode (Mo Al, etc.)
b. Gate insulation film (SiNx, etc.)
c. Semiconductor layer (a-Si a-Si (n +) P etc.)
d. Source / drain electrodes (Mo Al, etc.)
e. Transparent electrode (ITO etc.)
f. Protective film (SiNx, etc.)

First, the substrate 12 is fixed to the tray 10 with a clamp (not shown).
Each cathode is rotated and directed toward the substrate side and the back surface discharge side. The back surface discharge is used for target cleaning, and is preferably already performed before film formation, for example. In the case of a cathode as shown in FIG. 2, a maximum of three types of film formation can be performed. Also substrate
12 can be formed simultaneously by cathodes arranged on the left and right.

The tray 10 conveyed from the transfer chamber (not shown) stops at a predetermined position in the sputtering chamber 1 so that the mask (not shown) covers the entire frame of the tray 10 and does not have a film.

Next, simultaneously with loading of tray 10 and positioning of the target, the sputtering chamber
A sputtering gas such as Ar is added into 1. When the inside of the sputtering chamber 1 reaches a predetermined degree of vacuum, a voltage is applied to the cathode side to perform sputter deposition discharge.

After the film formation is completed, the cathode-side voltage and the sputtering gas are stopped, and then the tray 10 is transported from the sputtering chamber 1 to a vacuum processing chamber, not shown.

The preferred embodiments and examples of the present application have been described above with reference to the accompanying drawings, but the present invention is not limited to the embodiments and examples, and is understood from the description of the claims. It can be changed into various forms within the range.

1: Sputtering chamber
10: Tray
11: Gate valve
12: Board
13: Backside discharge space
14: Cooling mechanism
15: DC or high frequency power supply
16: Cleaning mechanism
17: Substrate holder
20, 21, 22, 20`, 21`, 22`, 25, 26, 27: Support
C20, C21, C22, C25, C26, C27: Center axis
20a, 20b, 20c, 21a, 21b, 21c, 22a, 22b, 22c, 25a, 25b, 25c, 26a, 26b, 26c, 27a, 27b, 27c: cathode mounting surface
30a, 30b, 30c, 31a, 31b, 31c, 32a, 32b, 32c, 35a, 35b, 35c, 36a, 36b, 36c, 37a, 37b, 37c: cathode
40a, 40b, 40c, 41a, 41b, 41c, 42a, 42b, 42c, 45a, 45b, 45c, 46a, 46b, 46c, 47a, 47b, 47c: Target
50, 51, 52, 50`, 51`, 52`, 55, 56, 57: Shield

Claims (3)

A sputtering chamber capable of evacuation; a plurality of rotatable supports for mounting a target provided in the sputtering chamber; and a plurality of surfaces provided on a plurality of surfaces of each of the supports so as to be separated from each other. And positioning the target mounted on the target mounting surface of the cathode by rotating each of the plurality of supports according to the position of the film formation surface of the substrate positioned in the sputtering chamber. In the sputtering apparatus for forming a film on the substrate, in order to perform plasma cleaning on the target of the support, a shield having a surface parallel to the surface of the target is disposed. . 2. The sputtering apparatus according to claim 1, wherein a coolant can flow through the shield. A method for manufacturing a display element using the sputtering apparatus.