Abstract:
A magnetic field generation control unit and a magnetron sputtering apparatus and method using the magnetic field generation control circuit. The magnetic field generation control unit includes a magnetic field generator for providing a specific magnetic field to a target consisting of a metal material to be deposited on a substrate, and a magnetic field generator control module electrically connected with the magnetic field generator, receiving an electrical signal from outside, and selectively supplying a current capable of generating the magnetic field to the magnetic field generator. The target is prevented from being magnetized when a sputtering process is not performed, and the magnetic field is generated from the target when the process is performed. Consequently, it is possible to perform uniform deposition on the substrate.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of Korean Application No. 10-2008-0066723, filed in the Korean Intellectual Property Office on Jul. 9, 2008, the disclosure of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    Aspects of the present invention relate to a magnetron sputtering apparatus, and more particularly, to a magnetic field generation control circuit capable of preventing a target from being magnetized and performing uniform deposition on a substrate, a magnetron sputtering apparatus having the magnetic field generation control circuit, and a magnetron sputtering method using the magnetic field generation control circuit. 
         [0004]    2. Description of the Related Art 
         [0005]    In the fabrication process of a semiconductor or liquid crystal display (LCD), a thin film process is typically performed to pattern a specific thin film or form a circuit pattern on an object to be processed, which is a parent material such as a wafer or a glass substrate. In the fabrication process of an LCD, a metal layer for forming a gate line and a data line and a transparent conductive film for forming a pixel electrode and a common electrode are deposited on a glass substrate using a sputtering method, and patterned to form a specific circuit pattern. 
         [0006]    According to the sputtering method, a process gas, such as argon or helium, is injected into a process chamber in a vacuum atmosphere to create a plasma atmosphere. The plasma ions are collided with a target, and atoms emitted from the target are deposited on a substrate. Lately, the sputtering method has been advanced. A magnetron sputtering method of causing plasma ions to impinge around the target is used. 
         [0007]      FIG. 1  shows a conventional magnetron sputtering apparatus. The conventional magnetron sputtering apparatus includes a process chamber  100  having a gas inlet pipe  110  and a gas outlet pipe  120 , a substrate support  130  installed in the process chamber  100  and on which a substrate  140  is placed, a magnet  50  disposed above the substrate support  130  in the process chamber  100 , a fixing plate  60  fixing the magnet  50  in the upper part of the process chamber  100 , and a target  200  disposed between the magnet  50  and the substrate support  130 . 
         [0008]    According to the above constitution, the magnet  50  generates a stronger magnetic field than a specific force and magnetizes the target  200  to generate a magnetic field required for a process. In this situation, when a plasma atmosphere is created in the process chamber  100  under vacuum, plasma ions may impinge around the magnetized target  200 . 
         [0009]    Since a specific amount or more of plasma ions are gathered around the target  200  and collide against the target  200 , a comparatively large amount of atoms of the target  200  can be emitted from the target  200  and deposited on the substrate  140  at a comparatively high rate. Such a magnetron sputtering apparatus facilitates control of the amount of deposited metal (such as nickel) and can be easily applied to a large substrate, and thus has been widely used. 
         [0010]    Unlike metal induced crystallization (MIC) or metal induced lateral crystallization (MILC), according to super grain silicon (SGS) crystallization, metal must be deposited on a substrate at a low concentration of, for example, 1011 to 1016 or less atom/cm 2 . Thus, it is very important to control the uniformity and rate of deposition on the substrate  140 . However, in the sputtering apparatus as shown in  FIG. 1 , the magnet  50  generates a uniform magnetic field even after the sputtering process is performed, and thus generates a uniform magnetic field from the target  200 . Since the target  200  continues to generate the uniform magnetic field even if the process is not performed, the target is magnetized and distorted. 
         [0011]    According to the conventional art, it is impossible to guarantee the deposition uniformity of metal deposited on the substrate  140  during the process due to the magnetized target  200 . In addition, when metal is deposited on the large substrate  140 , a separated magnetic field of the target  200  cannot be generated for a partial area. Thus, it is impossible to modify the deposition uniformity of a thin film deposited on the substrate  140 . 
       SUMMARY OF THE INVENTION 
       [0012]    Aspects of the present invention provide a magnetic field generation control unit that selectively controls magnetic field generation toward a target according to whether a sputtering process is performed on a substrate to prevent the target from being magnetized when the sputtering process is not performed and to generate a magnetic field toward the target and perform uniform deposition on the substrate when the sputtering process is performed, a magnetron sputtering apparatus having the magnetic field generation control unit, and a magnetron sputtering method using the magnetic field generation control unit. 
         [0013]    Additional aspects of the present invention provide a magnetic field generation control unit that reciprocates a target below a magnetron, which is a magnetic field generator, during a sputtering process and thus can uniformly deposit target material on a substrate; a magnetron sputtering apparatus having the magnetic field generation control unit; and a magnetron sputtering method using the magnetic field generation control unit. 
         [0014]    According to an aspect of the present invention, a magnetic field generation control unit is provided. The magnetic field generation control unit includes: a magnetic field generator to provide a specific magnetic field to a target having a metal material to be deposited on a substrate; and a magnetic field generator control module electrically connected with the magnetic field generator, to receive an electrical signal, and to selectively supply a current capable of generating the magnetic field to the magnetic field generator. 
         [0015]    According to another aspect of the present invention, the magnetic field generator further include: an inner ferrite formed in the shape of a bar having a specific length; a coil wound around the inner ferrite; and an outer ferrite surrounding the coil and having an external surface coated with nickel. 
         [0016]    According to another aspect of the present invention, the magnetic field generator further includes: an inner ferrite having a bar shape having a specific length; an inner coil wound around the inner ferrite; an outer coil wound around the inner coil; and an outer ferrite surrounding the outer coil and having an external surface coated with nickel. 
         [0017]    According to another aspect of the present invention, the magnetic field generation control unit further comprises only one magnetic field generator, and the one magnetic field generator is spaced apart from one surface of the target by a specific distance. 
         [0018]    According to another aspect of the present invention, the magnetic field generation control unit further comprises a plurality of the magnetic field generators parallel to each other and spaced apart from one surface of the target by a specific distance. 
         [0019]    According to another aspect of the present invention, the magnetic field generation control unit further includes a process controller electrically connected with the magnetic field generator control module to control a process of depositing the metal material on the substrate, and the process controller transfers the electrical signal to the magnetic field generator control module when the process of depositing the metal material on the substrate is performed. 
         [0020]    According to another aspect of the present invention, a magnetron sputtering apparatus having a magnetic field generation control unit is provided. The apparatus includes: a process chamber having a substrate support on which a substrate is placed; a target installed above the substrate support in the process chamber, including a metal material to be deposited on the substrate, and arranged so as to be movable along a specific reciprocating movement path; a magnetic field generator installed above the target in the process chamber, to provide a specific magnetic field to the target; a process controller to control a process of depositing the metal material on the substrate; and a magnetic field generator control module electrically connected with the process controller and the magnetic field generator, to receive an electrical signal indicating whether the process is performed from the process controller, to selectively move the target, and to selectively supply a current capable of generating the magnetic field to the magnetic field generator. 
         [0021]    According to another aspect of the present invention, the magnetron sputtering apparatus further includes a movement unit connected with the target, the movement unit including a fixing frame to fix both sides of the target, a guide frame to guide a sliding movement of the fixing frame, and a linear motor to slide the fixing frame. 
         [0022]    According to another aspect of the present invention, the magnetic field generator control module includes a movement controller and a current supply controller, the movement controller is electrically connected with the linear motor, and the current supply controller is electrically connected with the magnetic field generator. When the process of depositing the metal material on the substrate is performed, the magnetic field generator control module receives the electrical signal indicating that the process is performed from the process controller, reciprocate the target using the movement controller, and supply the specific current to the magnetic field generator using the current supply controller. 
         [0023]    According to another aspect of the present invention, a length direction of the magnetic field generator may cross the reciprocating movement path at right angles. 
         [0024]    According to another aspect of the present invention, a length of the magnetic field generators may be in the same direction as the reciprocating movement path. 
         [0025]    According to another aspect of the present invention, a magnetron sputtering method using a magnetic field generation control unit is provided. The method includes: determining, at a process controller, whether a process of depositing a metal material of a target on a substrate is performed; and determining, at a magnetic field generator control module, whether to supply a current for generating a magnetic field to a magnetic field generator for generating a magnetic field from the target according to whether the process is performed. 
         [0026]    Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
           [0028]      FIG. 1  illustrates a conventional magnetron sputtering apparatus; 
           [0029]      FIG. 2  illustrates a magnetron sputtering apparatus according to an embodiment of the present invention; 
           [0030]      FIG. 3  is an enlarged view of a part of  FIG. 2  indicated by a reference numeral A; 
           [0031]      FIG. 4  illustrates an example of the magnetic field generator of  FIG. 2 ; 
           [0032]      FIG. 5  illustrates another example of the magnetic field generator of  FIG. 2 ; 
           [0033]      FIG. 6  illustrates a magnetron sputtering apparatus according to another embodiment of the present invention; 
           [0034]      FIG. 7  illustrates an example of the magnetic field generator of  FIG. 6 ; 
           [0035]      FIG. 8  illustrates another example of the magnetic field generator of  FIG. 6 ; 
           [0036]      FIG. 9  is a flowchart showing operation of a magnetic field generation control unit according to an embodiment of the present invention; and 
           [0037]      FIG. 10  is a flowchart showing operation of a magnetic field generation control unit according to another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0038]    Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures. 
         [0039]      FIG. 2  shows a magnetron sputtering apparatus according to an embodiment of the present invention.  FIG. 3  is an enlarged view of a part of  FIG. 2  indicated by a reference numeral A.  FIG. 4  shows an example of a magnetic field generator of  FIG. 2 .  FIG. 5  shows another example of the magnetic field generator of  FIG. 2 .  FIG. 9  is a flowchart showing operation of a magnetic field generation control unit according to an embodiment of the present invention. 
         [0040]    As shown in  FIG. 2 , the magnetron sputtering apparatus having a magnetic field generation control unit includes a process chamber  100 , a target  200 , a magnetic field generator  400 , a process controller  500  and a magnetic field generator control module  600 . The process chamber  100  has a substrate support  130  on which a substrate  140  is placed. The target  200  is installed above the substrate support  130  in the process chamber  100 , and includes a metal material to be deposited on the substrate  140 . The target  200  is arranged so as to be movable along a specific reciprocating movement path. The magnetic field generator  400  is installed above the target  200  in the process chamber  100 , and provides a specific magnetic field to the target  200 . The process controller  500  controls a process of depositing the metal material onto the substrate  140 . The magnetic field generator control module  600  is electrically connected with the process controller  500  and the magnetic field generator  400 , and receives an electrical signal indicating whether the process is performed from the process controller  500  to selectively move the target  200  and to selectively supply a current capable of generating the magnetic field to the magnetic field generator  400 . 
         [0041]    The process chamber  100  has a gas inlet pipe  110  on one side, through which inert gas is injected, and a gas outlet pipe  120  on another side, through which gas is exhausted. The target  200  is connected with a movement unit  300 . 
         [0042]    The movement unit  300  includes a fixing frame  310  that fixes both sides of the target  200 , a guide frame  320  that guides the sliding movement of the fixing frame  310 , and a linear motor  330  that slides the fixing frame  310 . A sliding protrusion  311  is formed on the fixing frame  310 , and a sliding hole  321  in which the sliding protrusion  311  is inserted is formed in the guide frame  320  to guide the sliding movement of the fixing frame  310 . As a result, the target  200  can be reciprocated along the reciprocating movement path in a specific reciprocating section by the linear motor  330 . 
         [0043]    The process controller  500  controls the process. For example, the process controller  500  may put the substrate  140  on the substrate support  130 , create a vacuum required for the process in the process chamber  100  or inject the inert gas into the process chamber  100 , thereby allowing the sputtering process to proceed. The magnetic field generator  400  is fixed on a fixing plate  490  installed in the upper part within the process chamber  100  to be disposed above the target  200 . 
         [0044]    As shown in  FIGS. 4 and 5 , the magnetron sputtering apparatus may include the magnetic field generator  400  or a magnetic field generator  401 , each having a specific length. Here, the width direction of the magnetic field generator  400  crosses the reciprocating movement path of the target  200  at right angles. 
         [0045]    The magnetic field generator  400  may be a single coil type as shown in  FIG. 4 . The magnetic field generator  400  shown in  FIG. 4  includes an inner ferrite  410  that is formed in the shape of a bar having a specific length, a coil  420  wound around the inner ferrite  410 , and an outer ferrite  430  surrounding the coil  420  and having an external surface coated with nickel. 
         [0046]    The magnetic field generator  401  may be a dual coil type as shown in  FIG. 5 . The magnetic field generator  401  shown in  FIG. 5  may include an inner ferrite  411  that is formed in the shape of a bar having a specific length, an inner coil  421  wound around the inner ferrite  411 , an outer coil  422  wound around the inner coil  421 , and an outer ferrite  431  surrounding the outer coil  422  and having an external surface coated with nickel. 
         [0047]    The magnetic field generator control module  600  includes a movement controller  620  and a current supply controller  610  electrically connected with the process controller  500  as shown in  FIG. 2 . The movement controller  620  is electrically connected with the linear motor  330 . The current supply controller  610  is electrically connected with the magnetic field generator  400  or  401 . 
         [0048]    When the process of depositing the metal material on the substrate  140  is performed, the magnetic field generator control module  600  may receive the electrical signal indicating that the process is performed from the process controller  500 , reciprocate the target  200  using the movement controller  620 , and supply a specific current to the magnetic field generator  400  or  401  using the current supply controller  610  such that a specific magnetic field can be generated. 
         [0049]    Operation of the magnetron sputtering apparatus shown in  FIG. 2  will be described with reference to  FIGS. 2 ,  3 ,  4 ,  5  and  9 . Referring to  FIGS. 2 and 9 , the process controller  500  prepares a sputtering process in operation  100 . The process controller  500  operates a vacuum pump (not shown) capable of creating a vacuum in the process chamber  100 , moves and prepares the substrate  140  on the substrate support  130  using a transfer device (not shown), or injects inert gas from a gas supplier (not shown) into the process chamber  100  through the gas inlet pipe  110 . 
         [0050]    The process controller  500  transfers an electrical signal indicating that the process is performed to the magnetic field generator control module  600  while preparing the process as described above. In operation  200 , the magnetic field generator control module  600  determines whether the sputtering process is performed based on the electrical signal. 
         [0051]    If the sputtering process is performed as described above, the movement controller  620  of the magnetic field generator control module  600  may control the movement unit  300  to operate. In operation  300 , the linear motor  330  of the movement unit  300  operates such that the target  200  can reciprocate along the reciprocating movement path in a specific section at a specific rate as shown in  FIGS. 4 and 5 . 
         [0052]    The current supply controller  610  of the magnetic field generator control module  600  supplies a specific current to the magnetic field generator  400  or  401 . In operation  400 , the magnetic field generator  400  or  401  supplied with the current generates a specific magnetic field. 
         [0053]    The current supply controller  610  supplies the current to the magnetic field generator  400  or  401 . A magnetic field can be generated from the lower surface of the target  200  to have a strength of 200 to 800 gauss by a magnetic field generated by the magnetic field generator  400  or  401 . While the target  200  reciprocates along the reciprocating movement path below the magnetic field generator  400  or  401 , the magnetic field generator  400  or  401  may magnetize the target  200  using the specific magnetic field. 
         [0054]    The inert gas is injected into the process chamber  100  under vacuum, such that plasma can be generated in the process chamber  100 . The plasma ions are gathered around the magnetized target  200  and collide against the target  200 , and atoms emitted from the target  200  due to the collision may be deposited on the upper surface of the substrate  140  at a high rate. 
         [0055]    If no electrical signal is received from the process controller  500 , the magnetic field generator control module  600  determines that the sputtering process is not performed. The movement controller  620  of the magnetic field generator control module  600  then prevents the linear motor  330  from operating, thereby stopping movement of the target  200 . In operation  210 , the current supply controller  610  of the magnetic field generator control module  600  stops the current from being supplied to the magnetic field generator  400  or  401 . As a result, the magnetic field generator  400  or  401  will not generate a magnetic field. 
         [0056]    Consequently, the magnetic field generator control module  600  can prevent the target  200  from being magnetized by the magnetic field generator  400  or  401  while the sputtering process is not performed. In addition, when the dual coil type magnetic field generator  401  is used as shown in  FIG. 5 , the inner coil  421  and the outer coil  422  may have opposite polarities, such that the effect of an unbalanced magnetron deposition source can be obtained. 
         [0057]    A magnetron sputtering apparatus according to another embodiment of the present invention will be described with reference to  FIGS. 6 ,  7 ,  8  and  10 .  FIG. 6  shows a magnetron sputtering apparatus according to another embodiment of the present invention.  FIG. 7  shows an example of the magnetic field generator of  FIG. 6 .  FIG. 8  shows another example of the magnetic field generator of  FIG. 6 .  FIG. 10  is a flowchart showing operation of a magnetic field generation control unit according to another embodiment of the present invention. 
         [0058]    Referring to  FIG. 6 , the magnetron sputtering apparatus according to another embodiment of the present invention includes a process chamber  100 , a substrate support  130 , a target  200 , a movement unit  300  that reciprocates the target  200  along a reciprocating movement path, and a process controller  500 , which are similar to the corresponding units described above with respect to  FIG. 2 . The magnetron sputtering apparatus as shown in  FIG. 6  includes a magnetic field generator  700  or  701  and a magnetic field generator control module  600 , which are different from those of the magnetron sputtering apparatus shown in  FIG. 4 . 
         [0059]    The magnetic field generator  700  or  701  is fixed on a fixing plate  490  installed in the upper part within the process chamber  100  to be disposed above the target  200 . As shown in  FIGS. 7 and 8 , there are a plurality of the magnetic field generators  700  and  701  parallel to each other and spaced apart from one surface of the target  200  by a specific distance. The length of the magnetic field generators  700  and  701  may be in the same direction as the reciprocating movement path. 
         [0060]    As shown in  FIG. 7 , the magnetic field generator  700  is a single coil type. The magnetic field generator  700  includes an inner ferrite  710  that is formed in the shape of a bar having a specific length, a coil  720  wound around the inner ferrite  710 , and an outer ferrite  730  surrounding the coil  720  and having an external surface coated with nickel. 
         [0061]    The magnetic field generator  701  may be a dual coil type as shown in  FIG. 8 . The magnetic field generator  701  may include an inner ferrite  711  that is formed in the shape of a bar having a specific length, an inner coil  721  wound around the inner ferrite  711 , an outer coil  722  wound around the inner coil  721 , and an outer ferrite  731  surrounding the outer coil  722  and having an external surface coated with nickel. 
         [0062]    The magnetic field generator control module  600  includes a movement controller  620 , a current supply controller  610  and a current value input unit  630  electrically connected with the process controller  500  as shown in  FIG. 6 . The movement controller  620  is electrically connected with a linear motor  330 . The current supply controller  610  is electrically connected with the magnetic field generator  700 . The current value input unit  630  is electrically connected with the current supply controller  610  and may separately input the values of currents to be supplied to the magnetic field generators  700  into the current supply controller  610 . 
         [0063]    When a process of depositing a metal material on a substrate  140  is performed, the magnetic field generator control module  600  may receive an electrical signal indicating that the process is performed from the process controller  500 , reciprocate the target  200  using the movement controller  620 , and supply a specific current to the magnetic field generator  700  using the current supply controller  610  such that a specific magnetic field is generated. 
         [0064]    Operation of the magnetron sputtering apparatus shown in  FIG. 6  will be described with reference to  FIGS. 6 ,  7 ,  8  and  10 . Referring to  FIGS. 6 and 10 , the process controller  500  prepares a sputtering process in operation  100 . The process controller  500  transfers an electrical signal indicating that the process is performed to the magnetic field generator control module  600  while preparing the process as described above. In operation  200 , the magnetic field generator control module  600  determines whether the sputtering process is to be performed based on the electrical signal. 
         [0065]    If the sputtering process is to be performed, the current value input unit  630  of the magnetic field generator control module  600  inputs the values of currents to be separately supplied to the magnetic field generators  700  into the current supply controller  610  and sets the current values in operation  250 . 
         [0066]    The separate currents may be supplied from the current supply controller  610  to the respective magnetic field generators  700  disposed above the target  200 . The current value input unit  630  selectively inputs the values of the currents to be supplied to the magnetic field generators  700  into the current supply controller  610 , and the magnetic field generators  700  are aligned in parallel in the movement direction of the target  200 . The current value input unit  630  may input the values of the currents into the current supply controller  610  such that currents can be supplied only to the magnetic field generators  700  corresponding to the width of the target  200 . 
         [0067]    Since only the magnetic field generators  700  corresponding to various widths of the target  200  are operated, targets having various widths can be easily magnetized. In addition, the magnetic field generators  700  can generate magnetic fields using different currents due to the current value input unit  630 . As a result, the uniformity of a thin film deposited on the substrate  140  after the sputtering process may be easily modified in the following process. 
         [0068]    In operation  300 , the movement controller  620  of the magnetic field generator control module  600  controls the movement unit  300  to operate. The linear motor  330  of the movement unit  300  operates to reciprocate the target  200  along the reciprocating movement path in a specific section at a specific rate as shown in  FIGS. 7 and 8 . 
         [0069]    The current supply controller  610  of the magnetic field generator control module  600  may supply the currents according to the current values input from the current value input unit  630  to the respective magnetic field generators  700  or  701 . The magnetic field generators  700  or  701  supplied with the currents then generate a specific magnetic field. The current supply controller  610  supplies the currents to the magnetic field generators  700  or  701 . A magnetic field can be generated from the lower surface of the target  200  to have a strength of 200 to 800 gauss by the magnetic field generated by the magnetic field generators  700  or  701 . 
         [0070]    While the target  200  reciprocates along the reciprocating movement path a below the magnetic field generators  700  or  701 , the magnetic field generators  700  or  701  may magnetize the reciprocating target  200  using the specific magnetic field. In addition, inert gas is injected into the process chamber  100  under vacuum, such that plasma can be generated in the process chamber  100 . Subsequently, the plasma ions are gathered around the magnetized target  200  and collide against the target  200 , and atoms emitted from the target  200  due to the collision may be deposited on the upper surface of the substrate  140  at a high rate. 
         [0071]    If no electrical signal is received from the process controller  500  in operation  200 , the magnetic field generator control module  600  may determine that the sputtering process is not performed. The movement controller  620  of the magnetic field generator control module  600  prevents the linear motor  330  from operating, thereby stopping movement of the target  200 . In operation  210 , the current supply controller  610  of the magnetic field generator control module  600  stops current from being supplied to the magnetic field generators  700  or  701 . 
         [0072]    Thus, a magnetic field is not generated from the magnetic field generators  700  or  701 . Consequently, the magnetic field generator control module  600  can prevent the target  200  from being magnetized by the magnetic field generators  700  or  701  while the sputtering process is not performed. In addition, when the dual coil type magnetic field generator  701  is used as shown in  FIG. 8 , the inner coil  721  and the outer coil  722  may have opposite polarities, such that the effect of an unbalanced magnetron deposition source can be obtained. 
         [0073]    According to aspects of the present invention, magnetic field generation toward a target is selectively controlled according to whether a sputtering process is performed, and thus it is possible to prevent the target from being magnetized after the sputtering process. In addition, according to aspects of the present invention, a target is reciprocated below a magnetron, which is a magnetic field generator, during a sputtering process, such that a target material can be uniformly deposited on a substrate. 
         [0074]    Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.