CN107075664A - The Integral type rotary target of high performance-price ratio - Google Patents

Abstract

A monolithic rotating target is described. The target includes a sputter region and a flange region, wherein the sputter region is made of a first material and the flange region is made of the first material. The sputtering area and the flange area are integrally formed.

Description

Cost-effective monolithic rotating target

technical field

Embodiments described herein relate to layer deposition utilizing sputtering from a target. Embodiments described herein relate, inter alia, to rotating sputtering targets and apparatus including rotating sputtering targets. In particular, the present disclosure relates to integral rotating targets and apparatuses for depositing layers of material on substrates including integral rotating targets.

Background technique

Known techniques for depositing thin layers on substrates are, inter alia, evaporation, chemical vapor deposition and sputter deposition. For example, sputtering can be used to deposit thin layers such as thin layers of metals, eg aluminum or ceramics. During the sputtering process, the coating material is transferred from the sputtering target, which includes the material to be deposited, to the substrate by bombarding the surface of the target with ions. During the sputtering process, the target may be electrically biased such that ions generated in the treatment region may bombard the target surface with sufficient energy to dislodge atoms of the target material from the target surface. The sputtered atoms may be deposited on a substrate. Alternatively, the sputtered atoms can react with gases in the plasma, such as nitrogen or oxygen, to deposit materials such as oxides, nitrides, or oxynitrides on the substrate; this may be referred to as reactive sputtering.

There are two general types of sputtering targets: planar sputtering targets and rotating sputtering targets. There are advantages to both planar and rotary sputtering targets. Due to the geometry and design of the cathode, rotating targets have higher utilization and increased operating times compared to planar targets. Rotary sputtering targets are especially beneficial in large area substrate processing.

High-purity metal and metal alloy sputtering targets are used in semiconductor manufacturing. For example, high-purity aluminum alloy sputtering targets can be used in semiconductor manufacturing, as can other metal and metal alloy sputtering targets, such as copper, titanium, molybdenum sputtering targets. In terms of materials, metal and metal alloy targets can be provided as monolithic targets, ie targets without a backing tube. For monolithic targets, the target material itself, ie the material to be deposited in the substrate, can be self-supporting. The target material does not require a back tube to support the target material.

There is a continuing need in the semiconductor industry and other industries to reduce manufacturing costs including, but not limited to, the cost of ownership of manufacturing equipment, which also includes targets. Therefore, there is currently a need for cost-effective, mechanically reliable rotating targets.

Contents of the invention

According to the above, a monolithic rotating target, an apparatus for depositing a layer of material on a substrate and a method of manufacturing a monolithic rotating target according to independent claims 1 , 9 and 15 are provided. Other ideas, advantages and features of embodiments of the disclosure are apparent from the dependent claims, the description and the drawings.

According to one concept, a monolithic rotating target is provided. The target includes a sputter region and a flange region, wherein the sputter region is made of a first material and the flange region is made of the first material. The sputtering area and the flange area are integrally formed.

According to another concept, an apparatus for depositing material is provided. The apparatus includes a processing chamber and at least one integral rotating target comprising a sputtering region and a flange region, wherein the sputtering region and the flange region are made of a first material .

According to yet another aspect, a method of manufacturing a monolithic rotating target including a sputtering region and a flange region is provided. The method includes integrally forming the sputtering region and the flange region from the same material.

Description of drawings

So that so that the manner in which the above-mentioned features of embodiments of the present disclosure can be understood in detail, a more particular description of the embodiments briefly summarized above may be had by reference to the embodiments described herein, the accompanying drawings relating to implementations of the disclosure. method and described as follows;

Figure 1A shows a cross-section of a monolithic rotating target along the axis of rotation according to embodiments described herein;

Figure IB shows a detail of the flange region of a monolithic rotating target according to embodiments described herein;

Figure 2A shows a cross-section of a monolithic rotating target with a reusable cover along the axis of rotation, according to embodiments described herein;

Figure 2B shows a detail of a reusable cover for an integral rotating target according to embodiments described herein;

Figure 3 shows a top view of a monolithic rotating target according to embodiments described herein;

Figure 4 shows a top view of a deposition apparatus provided with an integral rotating target according to embodiments described herein; and

Figure 5 illustrates another deposition apparatus with an integral rotating target according to embodiments described herein.

detailed description

Reference will now be made in detail to various embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. In the following description of the drawings, the same reference numerals designate the same components. In general, only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of an embodiment of the disclosure and is not meant as a limitation of the embodiment. Additionally, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield a further embodiment. The description is intended to include such modifications and variations.

In the technical field of sputtering, a sputtering target assembly can have a sputtering target and a backing plate or backing tube. For example, the target material may be bonded to a backing plate or a backing tube, such as a backing tube made of stainless steel, copper, aluminum, or alloys of the aforementioned materials. The bonding process and structure of the target assembly not only increases the cost of the entire assembly of the assembly, but also increases the weight of the assembly and increases the risk of separation of the target assembly during use. This separation risk is further increased as the industry continues to grow to use larger and larger targets. Since the backing plate can be made of different materials than the target material, there is also a risk of contamination due to the coexistence of these materials and the target material. Therefore, monolithic targets are in demand.

As used herein, the term "monolithic" refers to a one-piece target unit without any separate or attached backing plate structure or backtube structure.

Monolithic targets generally have a target region, ie a sputtering region, and a flange region, which is made of a different material than the sputtering region. Monolithic rotating targets can be manufactured by casting or sintering the target material. Thus, a metal or metal alloy blank can be pressed to a predetermined height (eg at room temperature). A recrystallization anneal of the billet may then be performed, followed by quenching to room temperature. The recrystallized blank can be mechanically cold worked.

FIG. 1A shows a monolithic rotating target 100 along an axis of rotation 10 . The monolithic rotating target 100 may include a sputtering region 110 and a flange region 120 . The sputtering region may be made of a first material. The flange area may be made of the same material as the sputtering area. As shown in FIG. 1A , the sputtering region 110 and the flange region 120 may be integrally formed. The first material may be a material to be deposited on the substrate. Thus, during sputtering of the target, material can also be sputtered from said flange region, if this happens for any reason, without the risk of contamination by different materials co-existing with the rotating target. According to some embodiments, which may be combined with other embodiments described herein, flange region 120 may include flange 122 and intermediate portion 320 . The intermediate portion 320 may be disposed between the flange 122 and the sputtering region 110 . Additionally, the flange region 120 may be adapted to attach the rotating target 100 to an end-block within a processing chamber or deposition apparatus by using bolts or other mechanical fasteners (not shown). The end block can be configured to rotate the rotating target during sputtering. Additionally, or alternatively, the end block may be configured to provide cooling fluid and/or cooling power to the target for sputtering of the target.

The term "rotary target" as used herein refers to any cathode assembly adapted to be rotatably mounted to a deposition apparatus and comprising a target structure adapted to be sputtered. Accordingly, the term "rotating target" is used herein synonymously with "rotating cathode". Likewise, the term "sputtering region" as used herein refers to any enclosure, especially a hollow cylinder formed from a material suitable for sputtering. According to another embodiment, which may be used in combination with other embodiments described herein, the rotating target may be cylindrical, for example such that during rotation of the rotating target the distance between the substrate and the target surface constant. In addition, according to yet another embodiment, which can be used in combination with other embodiments described herein, compared to sputtering applications, the rotating target comprises a single deposition material, wherein switching between different target materials is performed by two or The rotational movement of two or more different targets is provided, or the switching between different targets is provided by the rotational movement of the different targets.

FIG. 1B shows an enlarged cross-sectional view of the flange region 120 of FIG. 1A . According to some embodiments, which may be used in combination with other embodiments described herein, the flange region may have increased strength. Thus, target deflection during sputtering is reduced and the mechanical reliability of the target is improved. Thus, a cost-effective and mechanically reliable target is provided. According to some embodiments, which may be used in combination with other embodiments described herein, this may be advantageously used for cantilever targets, which are supported on only one end of the target.

According to various embodiments, which may be used in combination with other embodiments described herein, the flange region 120 may undergo a machining process 130 . According to another embodiment, which may be used in combination with other embodiments described herein, the machining process may be a work hardening process, which increases the strength of the material in the flange region. According to embodiments herein, the machining process may cause permanent deformation of the material in the flange region. As a result, the strength of the flange area can be increased. Examples of work hardening processes may be induction hardening, shot peening, bead blasting, mechanical rolling, and the like.

Induction hardening can be used to selectively harden areas of a piece or assembly without affecting the properties of the entire part or assembly. According to the present embodiment, during induction hardening, the flange region 120 may be heated by induction heating and then hardened. The quenched flange region may undergo martensitic transformation to increase the hardness of the flange region. Shot peening can be used to create compressive residual stress layers and to adjust the mechanical properties of metals. According to this embodiment, which can be used in combination with other embodiments described herein, during shot peening, shots (such as round metal, glass or ceramic particles) can be used to impact the flange with a force sufficient to cause plastic deformation Area 120 surface.

As can be seen in FIG. 1A , the flange region 120 may adjoin the sputtering region 110 of the target 100 . Thus, increased strength may be provided for reducing target deflection and improving mechanical reliability of the target during sputtering. As a result, cost-effective and mechanically reliable targets are provided.

According to another embodiment, which may be used in combination with other embodiments described herein, the monolithic rotating target 100 may additionally include a cover 210, such as the reusable cover shown in FIG. 2A. The cover 210 may be made of a second material. The second material may be different from the first material.

According to an embodiment of the present disclosure, the first material may include metals and metal alloys, such as aluminum and aluminum alloys. Specifically, the first material may be high-purity aluminum. More specifically, the first material may be 5N aluminum having a purity of 99.999% by weight. According to another embodiment, which may be used in combination with other embodiments described herein, the metal and metal alloy may be selected from the group consisting of: copper, titanium, molybdenum, chromium and zinc. More specifically, said metal alloy may be selected from the group consisting of copper of grade 3.8 to 4.9% by weight, titanium of grade 3.0 to 3.9% by weight and molybdenum of grade 3.0 to 3.95% by weight.

According to yet another embodiment, which may be used in combination with other embodiments described herein, the first material may include a semiconductor material and a dielectric material (eg, ceramic). These materials can be used where monolithic targets can be fabricated.

According to various embodiments, which may be used in combination with other embodiments described herein, the second material may comprise a metal or a metal alloy. Specifically, the second material may be a metal alloy. More specifically, the second material may be an Al alloy.

According to embodiments described herein, the cover 210 may be a reusable cover 210 . The reusable cover may be adjacent to the sputtering region 110 and opposite the flange region 120 in the longitudinal direction of the target. The reusable lid may provide a sealed interior of the target, for example, a cooling fluid may be provided within the sealed interior. In addition, the reusable lid provides a cost-effective method of manufacturing the sealed interior of the target. According to some embodiments, which may be used in combination with other embodiments described herein, the reusable cap 210 may be attached (eg, screwed) onto the target 100 . Accordingly, reusable caps and targets may include threads. For example, the reusable cap can include male threads and the target can include female threads. As a result, a reusable cap can be screwed into the target as shown in Figure 2B. Reference numeral 230 shows the attachment between the male and female threads.

According to yet another embodiment, which may be used in combination with other embodiments described herein, the target and/or the cover may comprise threads such that bolts may be used to attach the cover to the target. Alternatively, other means may be used to attach the cover to the target, for example the cover may be welded to the target. However, welded caps may not be reusable.

FIG. 3 shows a top view of a monolithic rotating target 100 including a sputtering region 110 and a flange region 120 including a flange 122 and a middle portion 320 , according to embodiments described herein. As can be seen in FIG. 3, the sputtering region 110 and the flange 122 may be coaxial with each other. Intermediate portion 320 may be disposed between flange 122 and sputtering region 110 . Thus, the sputtering region, flange and intermediate portion can be coaxial with each other.

According to embodiments herein, the outer diameter of the middle portion may be smaller than the outer diameter of the sputtering region. Likewise, the outer diameter of the flange may optionally be larger than the outer diameter of the intermediate portion and larger than the outer diameter of the sputtering region. According to various embodiments, which may be used in combination with other embodiments described herein, the outer diameter of the flange may be 165 mm or greater, especially 171 mm or greater, more particularly 190 mm or greater. Furthermore, the outer diameter of the intermediate portion may be 145 mm or greater, especially 160 mm or greater, more particularly 170 mm or greater. The inner diameter of the target may be 125 mm or greater, especially 130 mm or greater, more particularly 135 mm or greater. Thus, the wall thickness of the central part in the radial direction may be 5 mm or more, and/or 25 mm or less, especially 7 mm to 20 mm.

FIG. 4 shows a deposition apparatus 400 having a processing chamber 402 and at least one integral rotating target 100 . Each integral rotating target 100 may contain a sputtering region and a flange region. The sputtering area and the flange area can be made of the first material. The first material may be a material to be deposited on the substrate. Thus, during target sputtering, material can also be sputtered from the flange region without the risk of contamination caused by different materials coexisting with the rotating target. The flange area may further be adapted to attach the monolithic rotating target 100 to the processing chamber 402 or deposition apparatus 400 by using screws or other mechanical fasteners (not shown).

According to another embodiment, which may be used in combination with other embodiments described herein, the flange region of the monolithic rotating cathode may be provided with increased strength. Thus, target deflection during sputtering is reduced and the mechanical reliability of the target is improved. As a result, cost-effective deposition equipment with mechanically reliable targets is provided.

According to yet another embodiment, which may be used in combination with other embodiments described herein, the integral rotating target 100 may be an integral rotating cathode.

The processing chamber 402 may be configured to be evacuated. For example, the processing chamber may have a vacuum flange 413 . Additionally, a pumping system (not shown) may be connected to chamber 402 to provide a technical vacuum in said chamber. Vacuum for the sputtering process may suitably be provided. For example, the process pressure may be between 1x10 ^-3 mbar and 10x10 ^-3 mbar.

The substrate support 422 may support the substrate 410 during deposition of a layer or thin film on the substrate by the rotating cathode. The cathode may be biased relative to the anode and/or relative to the chamber wall. Additionally, the substrate 410 or the substrate support 422 may be biased to deposit layers on the substrate 410 .

According to embodiments herein, the rotating cathodes may be provided as cathode pairs, such as rotatable MF dual cathodes. For ceramic targets like ITO, a DC sputtering process can be provided where the cathode is biased to a DC voltage. According to another embodiment, which may be used in combination with other embodiments described herein, sputtering from silicon, aluminum, molybdenum or similar targets may be performed by MF sputtering, ie intermediate frequency sputtering. According to embodiments herein, the intermediate frequency may be a frequency in the range of 5 kHz to 100 kHz, for example 10 kHz to 50 kHz. Sputtering from a target for a transparent conductive oxide film can be performed as DC sputtering.

According to various embodiments, which can be used in combination with other embodiments described herein, the substrate support 422 in the chamber 402 can be a support pedestal, where the substrate 410 can be provided on a pedestal with an actuator, such as a robotic arm. superior. Alternatively, the substrate support may be part of a substrate transfer system, where rollers may be provided to transfer the substrate into, eg, chamber 402 or out of chamber 402 . The roller system may guide the substrate or carrier, which in turn carries the substrate.

According to yet another different embodiment, which may be used in combination with other embodiments described herein, the substrate 410 may also be deposited in an in-line process in the case of a transfer system. In an inline process, the substrate may move through chamber 402 as it is being deposited. In this case, a chamber opening with a valve unit 408 or similar can also be provided on one side of the chamber 402 . In addition, another chamber may be provided on a side of the chamber 402 opposite to the chamber 401 . According to another embodiment, the chamber 401 may be a load lock chamber, a transfer chamber, eg including a robot, or may be an adjacent processing chamber, eg for deposition, etching, heating or similar processes.

According to some embodiments, which can be used in combination with other embodiments described herein, the embodiments described herein can be used for Display Physical Vapor Deposition (Display PVD), ie, sputter deposition on large area substrates for the display market. According to some embodiments, the large area substrate or corresponding carrier, wherein the carrier has a plurality of substrates, may have a dimension of at least 0.67 m2. The dimensions may range from about 0.67m2 (0.73mx0.92m-4.5 generations) to about 8m2, more typically from about 2m2 to about 9m2 or even up to 12m2. Substrates or supports for structures, devices such as cathode assemblies and methods according to embodiments described herein are large area substrates as described herein. For example, a large area substrate or carrier can be 4.5 generations, equivalent to about 0.67㎡ of substrate (0.73mx0.92m); 5 generations, equivalent to about 1.4㎡ of substrate (1.1mx1.3m); 7.5 generations, equivalent to about 4.29 ㎡ of substrate (1.95mx2.2m); 8.5 generations, equivalent to about 5.7㎡ of substrate (2.2mx2.5m); or even 10 generations, equivalent to about 8.7㎡ of substrate (2.85mx3.05m). Even larger generations, such as 11 and 12 generations and corresponding substrate areas can be similarly implemented.

FIG. 5 shows a schematic diagram of a deposition chamber 500 according to embodiments described herein. The deposition chamber 500 may be suitable for a deposition process, such as a PVD or CVD process. One or more substrates may be located on the substrate transfer device. According to some embodiments, the substrate support is movable to allow adjustment of the position of the substrate within the chamber. In particular, for large area substrates as described herein, deposition with a perpendicular substrate orientation or a substantially perpendicular substrate orientation can be performed. The transfer means may have a lower roller 522 which may be driven by one or more drives 525, such as motors. A drive 525 may be connected to the roller 522 by a shaft 523 for rotating the roller. Thus, it is possible for one motor to drive multiple rollers, for example by using belts, gear systems or the like to connect the rollers.

Rollers 524 may be used to support the substrate in a vertical or substantially vertical position. The substrate may be vertical or may deviate slightly from the vertical position, for example up to 5°. Large area substrates with a substrate size of 1 m2 to 9 m2 may be very thin, eg below 1 mm, such as 0.7 mm or even 0.5 mm. In order to support the substrate and provide the substrate in a fixed position, the substrate may be provided in a carrier during the processing of the substrate. Thus, the substrate may be transferred while supported in the carrier by a transfer system comprising, for example, a plurality of rollers and a drive. For example, a carrier with a substrate inside may be supported by a system of rollers 522 and 524 .

A source of deposition material, ie a rotating target according to embodiments described herein, may be disposed in the processing chamber on the side facing the substrate to be coated. A deposition material source may provide a first material 565 (ie, a deposition material) to be deposited on the substrate. As shown in FIG. 5 and according to embodiments described herein, the rotating target may be a monolithic rotating target 100 comprising a sputtering region and a flange region made of the same material. The sputtering area and the flange area may be integrally formed.

According to some embodiments, the deposition material indicated by reference numeral 565 during layer deposition may be selected according to the deposition process and subsequent application of the coated substrate. For example, the deposition material of the monolithic rotating target may be selected from the group consisting of: metals, metal alloys, semiconductor materials, and dielectric materials. Thus, an oxide layer, nitride layer, or carbide layer that may include such materials may be deposited by providing the material from a source or by reaction (i.e., a material from a source combined with oxygen, nitrogen, or carbon, for example, from a process gas. elemental reaction) to be deposited.

According to embodiments described herein, the monolithic rotating target can be used in a PVD chamber, such as from - PVD chamber purchased from a subsidiary of Applied Materials, Inc., Santa Clara, California, or from Applied Materials Gmbh & Co. KG, Alzenau, Germany. However, it should be understood that the described sputtering target assembly may have utility in other PVD chambers, including those configured to process large area substrates, substrates in the form of continuous webs, large area circular substrates chambers, and those produced by other manufacturers.

According to some embodiments, which may be used in combination with other embodiments described herein, the monolithic rotating target 100 may include a magnet assembly for increased deposition rates. A magnet assembly, which may include a magnet array, may be disposed within a sputtering target, such as within a monolithic rotating target, and may provide a magnetic field for magnetically enhanced sputtering. The target is rotatable about the longitudinal axis of the target such that the target is rotatable relative to the magnet member.

During operation, the magnet member can become hot. This is due to the fact that these magnet members are surrounded by the target material which is bombarded with ions. The resulting collisions on the target material can lead to heating of the rotating cathode. In order to keep the magnet at a suitable operating temperature, cooling of the target material and magnet may be provided.

According to yet another embodiment, which can be used in combination with other embodiments described herein, a tubular inner structure can be used to cool the monolithic rotating target. Specifically, the tubular internal structure can be used to cool the magnet assembly. The tubular inner structure may be liquid-tightly mounted to a coolant tube (not shown). Accordingly, a cooling fluid, such as water, may be circulated within the monolithic rotating target 100 for cooling the magnet and/or the target.

According to one concept, a monolithic rotating target is provided. The target includes a sputtering region and a flange region, wherein the sputtering region is made of a first material and the flange region is made of a first material. The sputtering area and the flange area are integrally formed.

According to another concept, a monolithic rotating target is provided. The target includes a sputtering region and a flange region, wherein the sputtering region is made of a first material and the flange region is made of a first material. The sputtering area and the flange area are integrally formed, wherein the flange area has increased strength.

According to another concept, an apparatus for depositing material is provided. The apparatus includes a processing chamber and at least one integral rotating target including a sputtering region and a flange region, wherein the sputtering region and the flange region are made of a first material.

Although the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure can also be devised without departing from the essential scope of the present invention, and the scope of protection of the present invention is determined by the appended claims. Book OK.

Claims (15)

1. A monolithic rotating target comprising a sputtering region and a flange region, wherein the sputtering region is made of a first material and the flange region is made of the first material, wherein the sputtering region The shot area and the flange area are integrally formed. 2. The target of claim 1, wherein the flange region has increased strength. 3. A target according to any one of claims 1 to 2, wherein the flange region has undergone a machining process. 4. The target of any one of claims 1 to 3, wherein the flange region is adjacent to the sputtering region of the target. 5. The target according to any one of claims 1 to 4, comprising a cover, wherein the cover is made of a second material different from the first material. 6. The target of claim 5, wherein the cover is a reusable cover, and wherein the reusable cover is adjacent to the sputtering region and in the longitudinal direction of the target with respect to the The flange area is opposite. 7. The target of any one of claims 1 to 6, wherein the first material comprises metals, metal alloys, semiconductor materials and dielectric materials. 8. A target according to any one of claims 5 to 7, wherein the second material comprises metals, metal alloys, semiconductor materials and dielectric materials. 9. The target of any one of claims 1 to 8, wherein the flange region comprises a flange and an intermediate portion. 10. The target according to claim 9, wherein the wall thickness of the intermediate portion in radial direction is 5 mm or more, in particular 7 mm to 20 mm. 11. The target according to any one of claims 9 to 10, wherein the outer diameter of the intermediate portion is smaller than the outer diameter of the sputtering region. 12. An apparatus for depositing material, said apparatus comprising: processing chamber; and At least one integral rotating target comprising a sputtering region and a flange region, wherein the sputtering region and the flange region are made of a first material. 13. The apparatus of claim 12, wherein the at least one integral rotating target is an integral rotating cathode. 14. The apparatus of any one of claims 12 to 13, wherein the at least one integral rotating target comprises a magnet assembly. 15. A method of manufacturing a monolithic rotating target comprising a sputtering region and a flange region integrally formed from the same material.