JPH07292469A - Sputtering device - Google Patents

Abstract

PURPOSE:To uniformize the film thickness on the surface of a substrate which is the body to be formed without deteriorating the film forming rate by sputtering. CONSTITUTION:The center axis (m) of a magnet system 13 is arranged at a position eccentric to the center axis (n) of a target sheet 12, the target sheet 12 is made ratatable with the center axis (m) of itself as the center of rotation, and it is rotated and driven by a driving motor 16. Thus, the yield of the product and its reliability are remarkably improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus for forming a thin film on a substrate placed on an anode by sputtering a target gas which is a cathode by ionized sputter gas and by atoms ejected from the target plate. , A sputtering system in which a magnet system for closing magnetic field lines is arranged behind a target plate.

[0002]

2. Description of the Related Art Generally, in a sputtering apparatus, an ionized Ar gas is sputtered on a target plate placed on a cathode by glow discharge, and a thin film is formed on a substrate placed on an anode by atoms or the like jumping out from the target plate. It is a device.

That is, in the above sputtering apparatus, first, for example, Ar at a pressure of about 1 × 10 ⁻⁴ Pa or less
A predetermined negative potential is applied to the cathode, that is, the target plate in the atmosphere. Then, an electric field is generated between the cathode and the anode, which are a pair of electrodes, and glow discharge occurs and ionized Ar gas sputters the target plate. As a result, the target material is ejected from the target plate in the state of atoms and the like, and the target material is deposited on the substrate placed on the anode surface facing the target plate to form a thin film. It

A magnetron sputtering apparatus is one of the preferable sputtering apparatuses that can meet the recent demand for increasing the sputtering rate. This device increases the sputtering efficiency by applying a predetermined magnetic field to the surface of the target plate in a direction orthogonal to the electric field generated between the cathode and the anode, and increases the film formation rate on the substrate.

FIG. 5 shows a state near the cathode of a conventional magnetron sputtering apparatus. As shown in this schematic diagram, a magnet system 103 is installed behind a cathode 101 having a target plate 102 arranged on its surface. A sputtering device having such a structure is called a flat plate type magnetron sputtering device (hereinafter, simply referred to as a flat plate type device).

Here, the magnet system 103 includes the S pole portion 10
3a has a shape surrounded by a circular N-pole portion 103b. The target plate 102 is installed on a backing plate 104 made of Cu or the like, and the backing plate 104 is connected to a power source (not shown) by a power line 105. Further, cooling water is supplied to the backing plate 104 through the cooling water line 106 to cool the target plate 102 during the sputtering.

Due to the shape of the magnet system 103, the leakage magnetic field applied to the target plate 102 has a closed donut shape. Electrons in the discharge plasma cause a cyclotron motion due to a component of the leakage magnetic field that is horizontal to the target plate 102 and an electric field that is perpendicular to the target plate 102, so that the electron density of that portion increases, and Ar of the sputtering gas Ionization is promoted. Therefore, the sputtering efficiency of the target plate 102 is improved and the film deposition density on the substrate is increased.

[0008]

However, in the flat plate type apparatus, the discharge plasma is easily collected at the apex portion of the magnetic force line due to the magnetic tunnel, and the surface of the target plate 102 corresponding to the apex portion is corroded. It gets fierce. That is, the erosion 111, which is a sputtered region on the surface of the target plate 102, becomes very narrow as shown in the drawing. For this reason, in the flat plate type device, the use efficiency of the target plate 102 is very low, about several% to 20%.

Further, since the erosion 111 is narrow, the shape of the target plate 102 changes remarkably as the erosion of the target plate 102 progresses, and as a result, the film thickness of the surface of the substrate, which is the film formation target, becomes extremely uneven. Become.

The present invention has been made in view of the above-mentioned various problems, and an object of the present invention is to form a film thickness on the surface of a substrate which is a film formation target without lowering the film formation rate by sputtering. The object is to provide a sputtering apparatus that makes it possible to significantly improve the yield and reliability of products by making them uniform.

[0011]

The object of the present invention is a sputtering apparatus having a substrate, a target plate arranged to face the substrate, and a magnet system installed behind the target plate. . According to the present invention, the target plate is provided with a drive mechanism that is movable with respect to the magnet system within a surface facing the magnet system.

In this case, specifically, a drive mechanism is provided in which the central axis of the magnet system is arranged at a position eccentric to the central axis of the target plate, and the target plate is rotationally driven about the central axis. Configure. That is, each position on the surface of the target plate rotationally moves within the surface facing the magnet system, and as a result, each position periodically moves with respect to the fixed magnet system.

In this case, a drive mechanism for swinging the target plate with respect to the magnet system may be provided. That is, each position on the surface of the target plate periodically translates in the surface facing the magnet system, and as a result, each position moves periodically with respect to the fixed magnet system. Become.

At this time, the shape of the target plate is a circle or a quadrangle. The circular target plate is particularly suitable for rotational driving around its central axis, and the quadrilateral target plate is particularly suitable for oscillating driving within the surface facing the magnet system. However, in the present invention, a target plate having a relatively simple shape that is easy to manufacture may be used, and a target plate other than a circular shape or a quadrangular shape may be used.

[0015]

In the sputtering apparatus according to the present invention,
A drive mechanism is provided in which a target plate, which is arranged to face the substrate that is the film formation target, is movable with respect to the magnet system in a surface facing the magnet system. In such a sputtering apparatus, the discharge plasma is easily collected at the apex of the magnetic force lines generated from the magnet system by the magnetic tunnel during the sputtering, and the degree of erosion of the surface of the target plate at the location corresponding to the apex is different from that of the target plate. It becomes larger than the part. In the present invention, since the surface of the target plate is movable with respect to the magnet system in the surface facing the magnet system, the peak portions of the magnetic force lines are almost evenly distributed over the entire surface of the target plate. Can be passed through. Moreover, since the magnet system is fixed, the state of the discharge plasma remains unchanged and the stability of the discharge plasma is ensured. Therefore, the erosion, which is the area to be sputtered, is greatly expanded, the degree of erosion of the surface of the target plate becomes substantially uniform over the entire surface, and the erosion on the anode arranged facing the target plate is increased. The film thickness of the surface of the substrate, which is a film-forming body, becomes substantially uniform, and the flying direction of sputtered particles (particles hit out when the target material is in the state of atoms, etc.) to the substrate becomes constant and the substrate becomes It is possible to easily control the growth direction of the film formed on the surface of the.

At this time, specifically, a drive mechanism is provided in which the central axis of the magnet system is arranged at a position eccentric with respect to the central axis of the target plate, and the target plate is rotationally driven about its own central axis. Therefore, by the easy operation of rotating the target plate, the erosion, which is the area to be sputtered, is greatly expanded, the degree of erosion of the surface of the target plate becomes substantially uniform over the entire surface, and it faces the target plate. The film thickness of the surface of the substrate, which is the film-formation target, placed on the anodes that are arranged in a uniform manner becomes almost uniform, and the direction of the sputtered particles flying toward the substrate becomes constant so that the surface of the substrate is formed. It is possible to easily control the growth direction of the formed film.

As another specific example, even in the case where a drive mechanism for swinging the target plate with respect to the magnet system is provided, sputtering is performed by an easy operation of swinging the target plate. The erosion, which is the region to be spread, greatly expands and the degree of erosion of the surface of the target plate becomes almost uniform over the entire surface, and the film-forming target placed on the anode facing the target plate is The film thickness on the surface of a certain substrate becomes almost uniform, and the flying direction of sputtered particles on the substrate becomes constant, which makes it possible to easily control the growth direction of the film formed on the surface of the substrate. .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some specific embodiments of the sputtering apparatus according to the present invention will be described below with reference to the drawings.

First, the first embodiment will be described. The sputtering apparatus according to the first embodiment increases the sputtering efficiency by applying a predetermined magnetic field to the surface of the target plate in a direction orthogonal to the electric field generated between the cathode and the anode, thereby increasing the deposition rate on the substrate. It is a so-called flat plate magnetron sputtering device (hereinafter simply referred to as a flat plate device) in which a magnet system is installed behind a cathode having the target plate arranged on the surface. is there.

Specifically, as shown in FIG. 1, the flat plate type apparatus includes a vacuum chamber 1 as a film forming chamber, a vacuum controller 2 for controlling a vacuum state in the vacuum chamber 1, and a plasma discharge device. Power source 3, a sputtering cathode portion 5 connected to the power source 3 through a power source line 4, an anode 6 arranged to face the sputtering cathode portion 5 with a predetermined distance, and a sputtering gas such as Ar is vacuumed. It comprises a sputtering gas supply unit 7 for supplying the gas into the chamber 1.

A target plate 12, which will be described later, which functions as a cathode, which is a component of the sputtering cathode portion 5, and a pair of electrodes are constituted by the anode 6, and a film is formed on the anode 6 so as to face the sputtering cathode portion 5. A substrate 8, which is a body, is installed.

The sputtering cathode portion 5 is composed of a target plate 12 arranged to face the substrate 8 and a magnet system 13 arranged behind the target plate 12.

When using the flat plate type apparatus, the inside of the vacuum chamber 1 is first set to a sufficiently good vacuum state, for example, 1 × 10 ^-4 Pa or less by the vacuum control unit 2. After that, a sputtering gas, for example, Ar is introduced into the vacuum chamber 1 from the sputtering gas supply unit 7 until the required pressure is reached. In this state, the backing plate 1 from the power source 3
1, that is, a predetermined negative potential is applied to the target plate 12.
Then, an electric field is generated between the backing plate 11 and the anode 6 which are a pair of electrodes, glow discharge occurs, and ionized Ar gas sputters the target plate 12. As a result, the target material is ejected from the target plate 12 in the state of atoms or the like, and this target material is deposited on the surface of the substrate 8 placed on the surface of the anode 6 arranged facing the target plate 12. Then, a thin film is formed.

Here, as shown in FIG. 2, a state near the sputtering cathode portion 5 is a target plate 12 which is a member to be sputtered, a backing plate 11 on which the target plate 12 is installed, and the backing plate 11. A magnet system 13 arranged behind, a chamber wall 14 to which the magnet system 13 is fixed, a dark shield 15 surrounding the backing plate 11,
A drive motor 16 which is a drive source is provided. In addition, cooling water is supplied to the backing plate 11 through a cooling water line 18 to cool the target plate 12 during sputtering.

The surface of the magnet system 13 facing the target plate 12 is circular, and a circular S pole portion 13a is formed in the center of the magnet system 13. The S pole portion 13a is concentrically formed around the S pole portion 13a. A circular N pole portion 13b is formed and configured as a closed structure. Here, the central axis m of the magnet system 13 is eccentric with respect to the central axis n of the target plate 12, and the central axes m and n are separated by a predetermined distance.

At this time, the magnet system 13 has a structure in which magnetic lines of force generated from the magnet system 13 are generated from the N pole portion 13b and returned to the S pole portion 13a.
Therefore, the lines of magnetic force form a closed tunnel shape, and the lines of magnetic force are applied to the target plate 12 with the apex portion as the center.

Further, the backing plate 11 is provided with a drive motor 16 for rotationally driving the backing plate 11 and the target plate 12.
2 is rotationally driven together with the backing plate 11 about the central axis n.

Therefore, due to this rotational drive, the target plate 12 relatively cyclically moves (rotates) with respect to the magnet system 13, and the magnet system 13 is substantially evenly distributed over the entire surface of the target plate 12. The vertices of the lines of magnetic force generated from will pass.

As described above, in the sputtering apparatus according to the first embodiment, the central axis m of the magnet system 13 is arranged at a position eccentric with respect to the central axis n of the target plate 12, and the target plate 12 itself. It is rotatable about a central axis m and is rotationally driven by a drive motor 16.

In such a sputtering apparatus, the discharge plasma easily gathers at the apex of the lines of magnetic force due to the magnetic tunnel during sputtering, and the degree of erosion of the surface of the target plate 12 corresponding to the apex is different from that of the target plate 12. It becomes larger than the part.

In the first embodiment, the surface of the target plate 12 is different from the magnet system 13 with respect to the magnet system 13.
Since it is possible to rotate and move in the surface facing the
As described above, it becomes possible to pass the peaks of the magnetic force lines almost uniformly over the entire surface of the target plate 12. Moreover, since the magnet system 13 is fixed, the state of the discharge plasma remains unchanged and the stability of the discharge plasma is ensured. Therefore, the erosion 17 that is the area to be sputtered is greatly expanded and the target plate 1
The degree of erosion of the surface of No. 2 spreads over the entire surface, and the film thickness of the surface of the substrate 8 which is the film-forming target placed on the anode 6 arranged facing the target plate 12. Are substantially uniform, and the flying direction of sputtered particles (particles hit by the target material in the state of atoms, etc.) to the substrate 8 is constant, and the substrate 8 is
It is possible to easily control the growth direction of the film formed on the surface of the.

Here, a comparative example with respect to the first embodiment will be described. This comparative example is different from the first embodiment in that the target plate 12 is fixed and the magnet portion 13 is rotatable. The same symbols are given to members and the like corresponding to the first embodiment.

That is, in the comparative example, the state near the sputtering cathode portion 5 is, as shown in FIG. 3, a target plate 12 which is a member to be sputtered.
A backing plate 11 on which the target plate 12 is installed, a magnet system 13 arranged behind the backing plate 11, a chamber wall 14 on which the magnet system 13 is installed, and the backing plate 11 A dark shield 15 and a drive motor 16 which is a rotational drive source of the magnet system 13 are provided. Magnet system 13
Is driven to rotate about its central axis n.

At this time, the use efficiency of the target plate 12 is increased to about 30 to 50%, but the apex of magnetic force lines generated from the magnet system 13 rotates with respect to the substrate 8 as the magnet system 13 rotates. As it moves, the discharge plasma will also rotate. Therefore, the state of the discharge plasma becomes unstable, and the film thickness on the surface of the substrate 8 becomes uneven. Further, the flying direction of sputtered particles with respect to the substrate 8 is not constant, and it becomes extremely difficult to control the growth direction of the film formed on the surface of the substrate 8.

Next, a second embodiment of the present invention will be described. The sputtering apparatus according to the second embodiment has almost the same configuration as that of the first embodiment, but the method of moving the magnet system, which is the constituent element, is different. The same symbols are given to members and the like corresponding to the first embodiment.

In the sputtering apparatus according to the second embodiment, the state near the sputtering cathode portion 5 is, as shown in FIG. 4, a target plate 12 which is a member to be sputtered, and the target plate 12 is installed. A backing plate 11, and a supporting portion 21 made of an insulating material for installing the backing plate 11,
A cylinder 22 which is connected to the support portion 21 and fixed to the chamber wall 14 and exerts pressure on the support portion 21, a magnet system 13 arranged behind the backing plate 11, and a chamber in which the magnet system 13 is fixed. A wall 14 and a dark shield 15 surrounding the backing plate 11 are provided.

Here, the magnet system 13 has a quadrangular shape, for example, a rectangular shape, facing the target plate 12, and the central axis passing through the center of gravity thereof coincides with the central axis n of the target plate 12. The target plate 12 is oscillated by the pressure from the cylinder 22 in a surface facing the magnet system 13 with the backing plate 11 and the support portion 21 about the central axis n. Therefore, due to this reciprocating movement, the target plate 12 relatively cyclically moves (reciprocating translational movement) with respect to the magnet system 13 and is generated from the magnet system 13 substantially uniformly over the entire surface of the target plate 12. The apex of the lines of magnetic force that pass through will pass.

As described above, in the sputtering apparatus according to the second embodiment, the surface of the target plate 12 can swing with respect to the magnet system 13 within the surface facing the magnet system 13. Therefore, as described above, it is possible to pass the apex portions of the magnetic force lines almost uniformly over the entire surface of the target plate 12. Moreover, since the magnet system 13 is fixed, the state of the discharge plasma remains unchanged and the stability of the discharge plasma is ensured. Therefore, the erosion 17 which is a region to be sputtered is greatly expanded, and the degree of erosion of the surface of the target plate 12 is spread over the entire surface, so that the anode 6 disposed opposite to the target plate 12 is spread. The film thickness of the surface of the substrate 8 which is the object to be film-formed on the substrate 8 becomes substantially uniform, and the flying direction of sputtered particles (particles hit out in a state where the target material is an atom, etc.) onto the substrate 8 Becomes constant, and the growth direction of the film formed on the surface of the substrate 8 can be easily controlled.

[0039]

According to the sputtering apparatus of the present invention, it has a substrate, a target plate arranged to face the substrate, and a magnet system installed behind the target plate.
Since the target plate is provided with a drive mechanism that is movable with respect to the magnet system within a surface facing the magnet system, the surface of the substrate that is the film formation target without reducing the film formation rate by sputtering. By making the film thickness uniform, it is possible to significantly improve the yield and reliability of products.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a sputtering apparatus according to a first embodiment.

FIG. 2 is a cross-sectional view schematically showing a state near a sputtering cathode portion, which is a constituent element of the sputtering apparatus.

FIG. 3 is a sectional view schematically showing a state near a sputtering cathode portion in a comparative example of the first embodiment.

FIG. 4 is a cross-sectional view schematically showing a state near a sputtering cathode portion, which is a constituent element of the sputtering apparatus according to the second embodiment.

FIG. 5 is a cross-sectional view schematically showing a state near a sputtering cathode portion, which is a constituent element of a conventional sputtering apparatus.

[Explanation of symbols]

 1 Vacuum Chamber 2 Vacuum Control Unit 3 Power Supply 4 Power Supply Line 5 Sputtering Cathode Unit 6 Anode 7 Sputter Gas Supply Unit 8 Substrate 11 Backing Plate 12 Target Plate 13 Magnet System 14 Chamber Wall 15 Dark Shield 16 Drive Motor 17 Erosion

Claims (5)

[Claims] 1. A substrate, a target plate arranged to face the substrate, and a magnet system installed behind the target plate, the target plate facing the magnet system with the magnet system. A sputtering apparatus having a driving mechanism that is movable in a plane. 2. A drive mechanism, which is arranged at a position where the center axis of the magnet system is eccentric with respect to the center axis of the target plate, and which drives the target plate to rotate about the center axis. 1. The sputtering apparatus according to 1. 3. The sputtering apparatus according to claim 1, wherein the target plate has a driving mechanism that swings the target plate. 4. The sputtering apparatus according to claim 1, wherein the target plate has a circular shape. 5. The sputtering apparatus according to claim 1, wherein the target plate has a quadrilateral shape.