TWI507557B - Magnetron and magnetron sputtering apparatus - Google Patents

Description

Magnetron and magnetron sputtering equipment [Cross-Reference to Related Applications]

The priority of the Korean Patent Application No. 10-2012-0149638, filed on Dec. 20, 2012, the entire disclosure of which is hereby incorporated by The way is incorporated in this article.

The present invention relates to a magnetron and a magnetron sputtering apparatus including the magnetron, and more particularly, to improving the use of a target by modifying a structure of a magnet disposed in a radius of gyration and a magnetron sputtering apparatus (target) the efficiency of the magnetron.

In general, a thin film sputter deposition method uses a target material to form a thin film, and the target material is sputtered by being generated by plasma generation and colliding with ions having high energy, the method actually A technique generally applied to semiconductor devices.

Developed in various forms depending on the purpose of using sputter deposition equipment The structure of the sputter deposition apparatus. However, efforts are still being made to increase their production. A sputter deposition apparatus is an apparatus for manufacturing a thin film by using a capacitive low-temperature plasma in which an air pressure is optimally maintained to allow ionization to be performed well, and positive and negative poles are installed in a vacuum vessel, and direct current , DC) or alternating current (AC) voltage is applied to the electrodes at both ends to generate a plasma.

As a general rule, positively charged ions present in the plasma are attracted to the cathode, and in contrast, negatively charged ions are directed toward the anode. In this case, due to the large and high electrical energy, the positively charged ions can allow the target material to be sputtered to deposit onto the target facing the sputtering at the moment of collision with the surface of the negative target. On the positive substrate of the material.

On the other hand, the negatively charged ions present in the plasma rush toward the positive substrate instead of the target, making it difficult to deposit the film on the positive substrate, which is called re-sputtering. When a magnetic field is applied to the generated plasma, a Lorentz force can be applied to the electrons in the plasma, and then can be according to the configuration of the magnet attached to the back of the target for sputtering. A desired plasma density spread is obtained. This is called magnetron sputtering. Therefore, magnetron sputtering can prevent re-sputtering and can increase the plasma density.

In general, magnetron sputtering is a physical vapor deposition method that increases the ionization rate around a target by applying an electric field and a magnetic field to a target to increase the sputtering rate, and is generally controlled by the deposited film. It is used for surface beauty and high density.

When an electric field and a magnetic field are applied to discharge the magnetron, the electricity released from the target The sub-connector is connected to a portion of the surface of the target while it is spiraling and jumping due to the applied electric and magnetic fields and the velocity of the discharged electrons. The ionization rate is increased in the locally concentrated region of the electrons, thereby increasing the sputtering rate. Therefore, in order to develop a high efficiency magnetron deposition source, it is necessary to control the battery and the magnetic field, and more specifically, to control the magnetic field is important.

For example, U.S. Patent No. 6,228,236 (issued to Rosenstein et al.), U.S. Patent No. 6,183,614 (issued to pay), U.S. Patent No. 4,995,958 (issued to Anderson et al.), Japanese Patent Early Publication No. Hei A sputtering technique using a magnetic field as described above is disclosed in Japanese Patent Laid-Open Publication No. Hei 9-310174, and Japanese Patent Application Laid-Open No. 10-1998-0065920.

As a method of forming a magnetic field, a magnet having a positive electrode and a negative electrode is disposed on a support substrate made of a magnetic metal. The polarity specifies the polarity in the direction towards the target. The corresponding polarities are set in a linear shape at a certain interval. When a structure having one pole magnet disposed completely around the arrangement of the other pole magnet is disposed, electrons and ions are confined in a region adjacent to the surface of the target, and the density is increased, thereby improving sputtering efficiency. Moreover, since the densely etched target occurs in the intermediate portion between the positive electrode and the negative electrode which are disposed in a linear form at a certain interval, in order to improve the efficiency of using the target and to provide uniformity of the thickness of the deposited film, It is necessary to optimize the settings of the positive and negative electrodes.

In order to increase the sputtering efficiency, according to the shape of the magnetron of the sputtering apparatus disclosed in U.S. Patent No. 6,228,236, the magnetron has a structure in which an outer magnet asymmetrically surrounds the inner magnet. Use has a double structure (two of which are circular structures) Sputtering devices of the magnetrons that are combined with one another) provide relatively good compensation for the Lorentz effect. However, there must be excessive chamber pressure to maintain the plasma, and a deeper asymmetric valley is formed in the target in a manner due to strong local etching, so that the uniformity of the etched target is not yet ideal. Uniformity and low efficiency in using the target.

Therefore, it is necessary to provide a new method of improving the efficiency of using a target by modifying the settings of the positive and negative electrodes while overcoming the limitations described above.

The present invention provides a magnetron sputtering apparatus capable of extending the length of a magnet to be used in a magnetron by a radius of less than 180 degrees from the center of the target, and more preferably within a radius of 90 degrees The lifetime of the target of the material used for sputtering.

According to an exemplary embodiment, a magnetron includes a support plate and a magnet disposed in a spiral shape extending from a central axis of rotation perpendicular to a surface of the support plate toward an edge. The magnet is divided into a plurality of sectors, and arcs are formed at equal intervals in respective sector regions, and a center of only one of the plurality of sectors is located on the central axis of rotation, and the center is located at The central angle of the sector on the axis of rotation is less than 180 degrees.

According to another exemplary embodiment, a magnetron includes a support plate and a magnet disposed in a spiral shape extending from a central axis of rotation perpendicular to a surface of the support plate toward an edge. The magnet is divided into four with a central angle of 90 degrees The sectors are arcuately formed at equal intervals in the respective sector regions, and the center of only one of the four sectors is located on the central axis of rotation.

The support plate may be a magnetic metal plate.

The magnetic metal plate may be formed of Martensitic stainless steel.

The magnet may be disposed in such a manner that a pair of first and second magnets alternately surround the central axis of rotation, and a gap may be formed between the first magnet and the second magnet to sandwich the first magnet and the second magnet with each other Separation.

The first magnet may be located in the outermost portion.

The first magnet and the second magnet may be belts having the same width.

One end of the first magnet may be disposed at the outermost portion while surrounding the outermost end of the second magnet, wherein the gap separates the first magnet from the second magnet.

The first magnet may be a positive electrode and the second magnet may be a negative electrode.

The central axis of rotation may be located on an inner end of one of the first magnet and the second magnet.

The gap may be formed as a closed track having a spiral ring shape.

The track may pass itself four or more times.

The track may be divided into a plurality of sectors, arcs are formed at equal intervals in respective sectors, and the center of only one of the plurality of sectors may be located on the center axis of rotation.

The respective sectors may have different centers, and magnets that form arcs at equal intervals in the respective sectors may be arranged to tangentially connect to adjacent sectors The magnet in the zone.

The respective sectors may have different centers, and arcs having equal spacing in the respective sectors may be concentric arcs having the center as its center point, respectively.

According to another exemplary embodiment, a magnetron sputtering apparatus includes a support unit that supports a substrate in a chamber, a target unit that is mounted facing the support unit, and is located behind the target unit and configured to surround a magnetron that rotates at the center of the target unit. The magnetron includes the features described above.

The target unit may include a target that supplies a deposition material to the substrate and a back plate disposed on a rear surface of the target.

100‧‧‧ chamber

110‧‧‧Support unit

101‧‧‧Substrate

121‧‧‧ Target

122‧‧‧ Backplane

130‧‧‧Target unit

140‧‧‧Power supply

150‧‧‧Magnetron

151‧‧‧First magnet

152‧‧‧second magnet

153‧‧‧ gap

The exemplary embodiments can be understood in more detail by the following description in conjunction with the drawings.

FIG. 1 is a view illustrating a magnetron sputtering apparatus according to an exemplary embodiment.

FIG. 2 is a view illustrating a magnetron according to an exemplary embodiment.

3 is a view illustrating a center point of each region of the magnetron of FIG. 2.

4 is a view illustrating the efficiency of using a target enhanced by the magnetron of FIG. 2.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. the same Reference numerals refer to the same components.

FIG. 1 is a view illustrating a magnetron sputtering apparatus according to an exemplary embodiment.

Referring to FIG. 1, the apparatus includes a chamber 100 in which a deposition technique is performed, a support unit 110 supporting a substrate 101 in a chamber 100, and a target unit 130 mounted opposite to the support unit 110 to supply electric power to a target The unit 130 is a power supply source 140 that generates plasma in the chamber 100, and a magnetron 150 that is located behind the target unit 130 and configured to rotate around the center of the target unit 130.

The target unit 130 includes a target 121 and a backing plate 122 that provide a material to be deposited on the surface of the substrate 101 by sputtering. The target unit 130 is disposed opposite and parallel to the substrate 101. In this case, the backing plate 122 may be formed of copper or other suitable material having a relatively high thermal conductivity, and may be attached to the top surface of the target 121 by various methods such as welding. Direct current (DC) or alternating current (AC) power is applied to the backplane 122 through the power supply source 140. The target unit 130 including the backing plate 122 and the target 121 can serve as an electrode of the device.

Moreover, according to the apparatus, the magnetron 150 is positioned above the target unit 130 as a magnetic field generating unit, thereby forming a closed loop magnetic field throughout the entire surface of the target 121. The magnetron 150 includes a magnet that is disposed in a spiral shape that is expanded toward the edge from a central axis of rotation that is perpendicular to a plane opposite to the target unit 130.

FIG. 2 is a view illustrating the magnetron 150. Referring to Fig. 2, the magnetron 150 includes a support plate and magnets 151 and 152 which are disposed in a spiral shape extending from a central axis of rotation perpendicular to a surface of the support plate toward an edge thereof. Magnets 151 and 152 are present on the surface of the support plate and are divided into four virtual A fan-shaped area having a central angle of 90 degrees. In each of the sectors, the magnets 151 and 152 form concentric arcs at equal intervals. The center of only one of the four sectors is disposed to be on the central axis of rotation. On the other hand, in the case of the magnetron 150, the spiral magnets 151 and 152 form at least five tracks in one sector centered on the central axis of rotation.

The target 121 is densely etched in the intermediate portion between the positive electrode and the negative electrode due to the arrangement of the spiral magnet forming the track. Therefore, an etched valley which is generated and has a track shape is displayed on the surface of the target 21. When the depth of the etched valley having the track shape reaches the depth of the target 121, the life of the target 121 ends, and the target 121 must be replaced.

The magnet 151 and the magnet 152 become the entire closed magnetic field, and the effect of grabbing the charged particles by the Lorentz force in the magnetic field is enhanced, and the density of ions or active substances in the plasma is further increased, thereby further improving Etching rate.

A pair of magnets 151 and 152 having mutually different polarities may include a first magnet 151 and a second magnet 152. The first magnet 151 may have a positive polarity and the second magnet 152 may have a negative polarity. In this case, the polarities of the first magnet 151 and the second magnet 152 specify the polarities shown at the front of the first magnet 151 and the second magnet 152, which extend toward the target unit 130. Also, the first magnet 151 and the second magnet 152 may be formed as belts having the same width.

In more detail, according to an exemplary embodiment, the support plate is formed of a magnetic metal plate. The first magnet 151 and the second magnet 152 are configured to enter a magnet element having a smaller column shape (eg, a cylindrical shape) and having the same polarity Line grouping. On the grouped magnet elements forming the first magnet 151 and the second magnet 152, a first magnetic metal plate and a second magnetic metal plate having a strip shape connecting the plurality of grouped magnet elements to each other are positioned. That is, the first magnet 151 and the second magnet 152 are in contact with and fixed to one of the support plates. The positive electrodes of the first magnets 151 extending toward the target 121 are all connected to the first magnetic metal plate having a spiral shape. The negative electrodes of the second magnets 152 extending toward the target 121 are all connected to a second magnetic metal plate having a spiral shape. On the other hand, the support plate and the first magnetic metal plate and the second magnetic metal plate which connect the positive electrode and the negative electrode to each other can be manufactured by using Martensitic stainless steel such as SUS420J1 and SUS420J2. Martensitic stainless steel is magnetic and contains chromium (12-14%), molybdenum (0.2-1%), nickel (less than 2%) and carbon (about 0.1-1%).

Moreover, the first magnet 151 and the second magnet 152 as shown in FIG. 2 are alternately disposed to rotate about a central axis of rotation, wherein the first magnet 151 is located in the outermost portion, and the second magnet 152 is located therein. On the other hand, one end of the first magnet 151 may be disposed at the outermost portion while surrounding the outermost end of the second magnet 152, wherein the gap 153 separates the first magnet 151 and the second magnet 152 from each other.

The gap 153 may be formed as a closed track having a spiral ring shape. The track is divided into a plurality of sectors, and arcs are formed at equal intervals in the respective sectors in a manner such that the center of only one of the plurality of sectors can be located on the central axis of rotation, And it can pass four or more times by itself, thereby forming five or more multiple tracks with respect to the central axis of rotation. The tracks are arranged in a spiral ring shape, allowing an effective method of maintaining plasma to provide closed drift Current loop.

As described above, the magnets 151 and 152 provided in the apparatus are divided into four virtual sectors, the central angle of which is 90 degrees. The corresponding sectors have different centers. Magnets 151 and 152 that form arcs at equal intervals in the respective sectors are disposed tangentially to arcs that are located at equal intervals in adjacent sectors. In another aspect, the respective sectors have different centers, and the arcs having equal spacing in the respective sectors form concentric arcs, the center point of the concentric arc being the center point of the corresponding zone.

In detail, as shown in FIG. 3, the magnetron 150 is divided into first to fourth regions having a sector shape, the central angle of which is 90 degrees, and the interval between the positive electrode and the negative electrode in all regions Equally, the magnets 151 and 152 are disposed as arcs in the respective sectors, except that the first, second, third, and fourth regions may be arranged to allow arcs having different radii to be tangentially connected to each other, When the coordinates of the center point of the first region are (0, 0), the magnets 151 and 152 may be disposed in such a manner that the second region has a point shifted by a distance 'a' toward the third region with respect to the central axis of rotation. As a center point of coordinates (a, 0) and a plurality of concentric arcs are formed, the third region has a point shifted to the right by a distance 'a' with respect to the central axis of rotation and a distance of distance 'b' from the fourth region As a center point of (a, b), a plurality of concentric arcs are formed, and the fourth region has a point shifted downward by a distance 'b' with respect to the center point as a center of coordinates (0, b) Points are formed and a plurality of concentric arcs. In this case, a plurality of concentric arcs formed at different center points in the first to fourth regions may be connected to each other to form a gentle tangent. When using the above description When the method is divided into four sectors having a central angle of 90 degrees, since the adjacent portions of the corresponding regions can be simply connected as a tangent, the magnets 151 and 152 can be set to a simple configuration without the need for setting the magnet. Complex design process.

However, since the magnets 151 and 152 are disposed in the region on the rotation center of the magnetron 150, the center of the sector is densely etched due to the rotation of the magnetron 150, thereby forming a track-shaped etching valley, The central angle of the sector centered on the center of rotation is small, so that the efficiency of using the target 121 can be further improved. However, in this case, it is difficult to provide uniformity of the thickness of the deposited film.

In this case, 'a' and 'b' as positioning parameters for determining the center points of the first to fourth regions can be considered by considering the uniformity of deposition, the environment within the chamber 100, and the magnetron 150. The effect of rotation is optimized by changing its own value, where 'a' + 'b' is the loop of the interval between the tracks. Preferably, 'a' and 'b' are selected within a range satisfying 'a' + 'b' = 42.8 mm, and the magnets 151 and 152 are disposed in the second, third, and fourth regions. When 'a' = 'b' = 21.4 mm, the second region, the third region, and the fourth region may be equally divided.

Moreover, when four or more regions are applied, the central angle of the sector which becomes the center of rotation of the magnetron 150 can be further reduced. Preferably, the efficiency of using the target 121 can be improved by reducing the central angle of the sector to less than 60 degrees. On the other hand, when a rotation angle having a certain radius is selected, the uniformity of the deposited film and the design aspect of the magnetron 150 must be considered together with the improvement in the efficiency of using the target 121.

In general, a sputtering apparatus for depositing a metal layer or various types of inorganic films requires a magnetron device to increase the plasma generated in the entire target region. density. The magnetron device is disposed on the rear surface of the target. The magnetic field generated by the magnetron allows electrons in the plasma generated around the front surface of the target to concentrate on a region adjacent to the surface of the target, thereby further increasing the density of the plasma. Due to the effects described above, the rate at which material is deposited by sputtering can be increased.

In this case, the etching shape of the surface of the target is determined according to the shape of the positive and negative electrodes of the magnetron, and the efficiency of using the target is improved, thereby uniformly etching the entire surface of the target. On the other hand, the target material etched from the target determines the uniformity of the deposited thickness of the target material deposited on the substrate. Thus, the configuration of the positive and negative electrodes of the magnetron is capable of uniformly etching the target material while providing uniformity of thickness of the material deposited on the substrate and maximizing the efficiency of use of the target.

Subsequently, a magnet formed of a positive electrode and a negative electrode was disposed in the magnetron while being divided into four sectors, the central angle of which was 90 degrees. The center of only one of the four sectors will coincide with the central axis of rotation of the magnetron. The respective magnets of the four sectors are arranged to be separated from each other at equal intervals, thereby allowing the center point of the respective sector as a concentric arc to allow all arcs to be tangentially connected, thereby increasing the efficiency of using the target and providing deposition on the substrate. The uniformity of the thickness of the film.

Therefore, in the sputtering apparatus including the magnetron according to the exemplary embodiment, the magnet is disposed in a magnetron rotated by a separately mounted motor at a radius within a range of 90 degrees, thereby greatly reducing the target The depth of the etched pattern. Another region within the range of 270 degrees is the spiral connection portion for forming the closed structure, and expands the width of the etched valley formed by another region within the range of 270 degrees. The sputter etching pattern crosses each other due to the rotation of the magnetron of the magnets arranged as described above, and thus further Improve the efficiency of using targets.

In the magnetron according to an exemplary embodiment, the configuration in which the magnet is disposed is changed to reduce a considerable portion of the depth of the local etching of the target as shown in FIG. 4, thereby improving the efficiency of using the target. (a) in FIG. 4 is a view illustrating a state in which the target 121 is etched through a magnetron including a magnet arranged in a concentric arc having a certain radius within a range of 180 degrees (ie, two of the four regions). . (b) in FIG. 4 is a view illustrating a state in which the target 121 is etched through a magnetron including a magnet arranged in a concentric arc (i.e., one of four regions) having a radius within a range of 90 degrees. . Referring to FIG. 4, it can be known that when a magnetron according to an exemplary embodiment is used, the efficiency of using the target 121 disposed on the backing plate 122 can be remarkably improved.

On the other hand, the central angle of the arc area having the center equivalent to the center of the rotation of the magnetron is not necessarily 90 degrees, that is, one of the four areas in the exemplary embodiment as described above. There is no need to divide the whole into four regions. The concentric arc is in a portion of the entire area of the magnetron. In other cases, the magnets are not set to concentric arcs. Preferably, the magnetron according to another embodiment includes a support plate and a magnet disposed in a spiral shape extending from a central axis of rotation perpendicular to a surface of the support plate toward the edge. The magnet is divided into a plurality of sectors. The magnets form an arc at equal intervals in the respective sectors. The center of only one of the plurality of sectors is allowed to be located on the central axis of rotation. The central angle of the sector centered on the axis of rotation is allowed to be less than 180 degrees. In order to further increase the efficiency of using the target by reducing the depth of the target etching pattern, it is more preferable that the central angle of the sector in the first region may be less than 60 degrees. On the other hand, consider using a target The improvement in efficiency, the uniformity of the deposited film, and the design aspect of the magnetron are used to determine the central angle of the first region having concentric arcs separated at equal intervals.

In accordance with one or more embodiments, a magnetron sputtering apparatus wherein magnets are arranged in concentric arcs at equal intervals from a central axis of rotation of the magnetron, and only one of the four regions has a sector shape with a central angle of 90 degrees Further, the uniformity of the thickness of the material deposited on the substrate is provided by uniformly etching the target material while improving the efficiency of using the target.

Moreover, by increasing the efficiency of using the target, the amount of the expensive target used is reduced, thereby reducing the manufacturing cost and extending the loop of the replacement target, thereby prolonging the cycle of the operation time of the device. Therefore, the productivity of the device will increase.

Although the magnetron and magnetron sputtering apparatus have been described with reference to specific embodiments, it is not limited thereto. Therefore, it will be apparent to those skilled in the art that various modifications and changes can be made in the invention.

150‧‧‧Magnetron

151‧‧‧First magnet

152‧‧‧second magnet

153‧‧‧ gap

Claims (17)

A magnetron comprising: a support plate; and a magnet disposed in a spiral shape extending from a central axis of rotation perpendicular to a surface of the support plate toward the edge, wherein the magnet is divided into a plurality of sectors, and correspondingly Forming an arc at equal intervals in the sector, and wherein a center of only one of the plurality of sectors is located on the central axis of rotation, and a central angle of the sector centered on the central axis of rotation Less than 180 degrees. A magnetron comprising: a support plate; and a magnet disposed in a spiral shape extending from a central axis of rotation perpendicular to a surface of the support plate toward the edge, wherein the magnet is divided into four with a central angle of 90 degrees Sectors, and arcs are formed at equal intervals in respective sectors, and wherein the center of only one of the four sectors is located on the central axis of rotation. The magnetron of any one of claims 1 to 2, wherein the support plate is a magnetic metal plate. The magnetron of claim 3, wherein the magnetic metal plate is formed of Martensitic stainless steel. The magnetron of any one of claims 1 to 2, wherein the magnet is disposed in a manner such that a pair of first and second magnets having different polarities alternately surround the rotation a central axis, and a gap is formed between the first magnet and the second magnet to separate the first magnet and the second magnet from each other. The magnetron of claim 5, wherein the first magnet is located in an outermost portion. The magnetron of claim 5, wherein the first magnet and the second magnet are strips having the same width. The magnetron of claim 5, wherein one end of the first magnet is disposed at an outermost portion while surrounding an outermost end of the second magnet, wherein the gap is the first The magnet is separated from the second magnet. The magnetron of claim 5, wherein the first magnet is a positive electrode and the second magnet is a negative electrode. The magnetron of claim 5, wherein the center axis of rotation is on an inner end of one of the first magnet and the second magnet. The magnetron of claim 5, wherein the gap is formed as a closed orbit having a spiral ring shape. The magnetron of claim 11, wherein the track passes through itself four or more times. The magnetron of claim 11, wherein the track is divided into a plurality of sectors, and arcs are formed at equal intervals in the corresponding sector. And the center of only one of the plurality of sectors is located on the central axis of rotation. The magnetron of any one of claims 1 to 2, wherein the respective sector shapes have different centers, and the magnets forming arcs at equal intervals in the respective sector regions are set to be cut. The magnets are connected to the adjacent sectors in a directional manner. The magnetron of any one of claims 1 to 2, wherein the respective sector shapes have different centers, and the arcs having equal intervals in the respective sector regions are respectively The center is taken as a concentric arc of its center point. A magnetron sputtering apparatus comprising: a support unit supporting a substrate in a chamber; a target unit mounted for the support unit; and a magnetron disposed behind the target unit and configured to surround the Rotating the center of the target unit, wherein the magnetron is a magnetron as described in any of claims 1 and 2. The magnetron sputtering apparatus of claim 15, wherein the target unit comprises a target that supplies a deposition material to the substrate and a backing plate disposed on a rear surface of the target.