This application claims the benefit of Korean Patent Application No. 10-2013-0088273, filed on Jul. 25, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
One or more embodiments of the present invention relate to a sputtering apparatus, and more particularly, to a facing target sputtering apparatus in which a plurality of targets are arranged facing each other to form a deposition on a substrate.
2. Description of the Related Art
For example, thin film encapsulation used for an organic light-emitting display device (OLED) is manufactured by a deposition process such as sputtering. In other words, a thin film having a desired encapsulation function is formed on a substrate of an OLED, which is an object to be deposited, by sputtering with a prepared deposition target. Recently, among the sputtering methods, a facing target sputtering method, in which targets are arranged to face each other and discharge occurs so that high density plasma is formed to perform deposition, is widely being used.
However, during the sputtering with the facing target sputtering apparatus, electrons, which are included in the plasma and are hovering along an edge of a plasma area, are generated. When the electrons start to escape from the plasma area, instead of being confined therein, peripheral devices or the substrate that is subject to deposition may be damaged by the electrons. Such damage may badly affect both of lifespan of an apparatus and quality of a product, and thus a solution to effectively solve the problems are needed.
One or more embodiments of the present invention include a sputtering apparatus which may prevent escape of electrons from a plasma area, reduce danger of damaging the periphery, and stabilize plasma.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.
According to one or more embodiments of the present invention, a sputtering apparatus includes a plurality of targets arranged to face each other and a magnetic member producing a magnetic field that is to be formed in a space between the plurality of targets. The magnetic member includes a bar magnet and a cylindrical magnet.
The magnetic member may have a shape of a polygonal frame, and the bar magnet may be arranged along each side of the polygonal frame and the cylindrical magnet may be arranged at a vertex between the sides of the polygonal frame.
The magnetic member may have a shape of a rectangular frame, and the bar magnet may have arranged along each of four sides of the rectangular frame and the cylindrical magnet may have arranged at each of four vertices of the rectangular frame.
The bar magnet and the cylindrical magnet may be separated from each other with an interval.
The magnetic member may be arranged behind each of the plurality of targets facing each other.
The bar magnet and the cylindrical magnet may be arranged surrounding an outer side of each of the plurality of the targets.
The magnetic member may be arranges in a manner that when plasma is formed between the plurality of the targets, electrons included in the plasma may circulate along a peripheral region of the magnetic field produced from the magnetic member.
These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description.
The structure of the sputtering apparatus 100 for scattering the particles of the targets 110 according to the present embodiment will be described in detail.
Referring to
A shield portion 140 is arranged maintaining a fine interval with each of the targets 110 to initiate discharge. A power unit 160 applies a negative voltage (first voltage) to the targets 110 and a positive voltage (ground voltage or second voltage) to the shield portion 140 during the sputtering process. Although a direct current (DC) power is illustrated as the power of the power unit 160 in
The magnetic members 120 are provided to surround the outer side of each of the targets 110. A detailed structure is illustrated in
As illustrated in
When the circulating electrons e are continuously confined in the plasma area, there will be no problem. However, as described above, if the electrons e escape from the plasma area, the substrate 10 or peripheral devices may be damaged so that lifespan of an apparatus and the substrate 10 to be manufactured into a product may be ill affected. However, when the magnetic member 120 having the above structure according to the present embodiment is employed, the electron escape phenomenon is sufficiently reduced.
As such, since plasma is very stably maintained during sputtering, the sputtering may be generally very stably performed. When the number of escaping electrons increases, plasma is not uniformly formed and is lopsidedly formed in an area where more number of the escaping electrons are present and thus a thin film is irregularly formed. When plasma is stably formed, a thin film deposited on the substrate 10 may be uniformly formed.
For reference, the bar magnets 121 and the cylindrical magnets 122 of the magnetic member 120 may be formed of, for example, a ferrite-based magnet, a neodymium-based magnet, a samarium cobalt-based magnet.
A deposition process using the sputtering apparatus 100 according to the present embodiment will be performed as follows.
First, as illustrated in
When the substrate 10 and the targets 110 are prepared, argon gas is supplied to the inside of the deposition chamber 200 and sputtering is initiated while reciprocating the shuttle 40. As sputtering starts, a negative power is applied to the targets 110 and a positive voltage is applied to the shield portion 140, thereby generating discharge. Accordingly, electrons generated by the discharge collide against the argon gas and thus argon ions (Ar+ ions) are generated. Then, plasma including Ar+ ions is formed between the targets 110.
The generated plasma is maintained being confined in a space between the targets 110 facing each other by the magnetic field M of the magnetic member 120. The plasma includes various particles such as electrons, negative ions, and positive ions. The particles reciprocate between the targets 110 facing each other, maintaining high density plasma.
In this state, as the Ar+ ions in the plasma collide against the targets 110 to which a negative voltage is applied, target particles are scattered. Then, the target particles scattered from the targets 110 are deposited on the substrate 10 over the mask 20, thereby forming a thin film on the substrate 10.
While the sputtering is performed, the electrons e circulating along the peripheral region of the plasma area smoothly move along the magnetic member 120 including the bar magnets 121 and the cylindrical magnets 122, as described above. Thus, the substrate 10 or peripheral devices may be prevented from being damaged by the escaped electrons.
Thus, as described above, when deposition is performed by using the sputtering apparatus according to the present invention, escape of electrons from plasma may be prevented and stable plasma may be maintained. Thus, damage to the peripheral devices due to the escaping electrons may be reduced and the quality of a product may be stabilized.
Although only one sputtering apparatus 100 is provided in the deposition chamber 200 in the present embodiment, the number of the sputtering apparatus 100 may vary as necessary.
It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.
While one or more embodiments of the present invention have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
Number | Date | Country | Kind |
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10-2013-0088273 | Jul 2013 | KR | national |