Abstract:
A sputtering apparatus for depositing a target material on a substrate includes a chamber, a target in the chamber to provide the target material, a carrier to carry the substrate in the chamber to face the target, and a plurality of masks arranged along sides of the carrier and being movable back and forth with respect to the carrier.

Description:
This application claims the benefit of the Korean Patent Application No. 2005-50258 filed in Korea on Jun. 13, 2005, which is hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a sputtering apparatus, and more particularly, to a sputtering apparatus and a method of driving the sputtering apparatus that are capable of achieving an optimum deposition. 
     2. Background of the Related Art 
     In general, a sputtering apparatus typically deposits a target material on a substrate by colliding ions accelerated in plasma with a target. As compared to a chemical vapor deposition (CVD) apparatus that performs processes at a high temperature, the sputtering apparatus is advantageous in performing a sputtering process where a thin film can be formed while a substrate is maintained at a low temperature of about 400° C. Such a sputtering apparatus has been widely utilized for a flat panel display device such as a liquid crystal display (LCD) device, an organic electroluminescence device, or the like because of its simple structure and formation of a deposition layer in a short period of time. 
     The conventional sputtering apparatus has a cathode connected to a target, which is provided in a chamber, and an anode connected to a substrate. When a predetermined voltage is applied between the cathode and the anode, electrons are bombarded with an inert gas and are thus ionized. When the ionized positive ions are accelerated toward the cathode target and collide with the target, a target material is sputtered from the target, thereby depositing the target material on the substrate to form a predetermined layer. The electrons are excited by bombarding neutral atoms to thereby generate plasma. The plasma is maintained when an external potential is maintained and electrons are continuously generated. 
     The sputtering apparatus may be classified into a cluster type and an in-line type.  FIG. 1  is a schematic cross-sectional view illustrating a cluster type-sputtering apparatus according to the related art. As shown in  FIG. 1 , the related art cluster type sputtering apparatus includes a chamber  100  that serves to accommodate a substrate  110  transferred from the outside, a lifter  120  that is able to be placed upright to support the substrate  110 , a target  130  including a target material to be deposited onto the substrate  110 , and a mask  140  arranged in front of the target  130 . Specifically, the substrate  110  is transferred horizontally into the chamber  100  and mounted on the lifter  120 . Then, the lifter  120  carrying the substrate  110  is lifted upright in the chamber  100 , and a sputtering process is thus performed. This sputtering apparatus is advantageous in that the degree to which the vacuum and temperature change is minimized because the lifter  120  constantly maintains the vacuum and certain temperature. Also, a gap of about 5 mm between the mask  140  and the substrate  110  within the chamber  100  can be maintained, thereby minimizing the deposition of the target material from the target  130  onto the lifter  120  supporting the substrate  110 . However, such a cluster type sputtering apparatus cannot perform a deposition process for a large-sized substrate, which is greater than 2 m×2 m, due to the weight of equipment and an increase in pump capacity. 
     Recently, an in-line type sputtering apparatus has been increasingly utilized to perform the deposition process for large-sized substrates.  FIG. 2A  is a plan view schematically illustrating an in-line type sputtering apparatus according to the related art.  FIG. 2B  is a cross-sectional view schematically illustrating the in-line type sputtering apparatus within a chamber. As shown in  FIGS. 2A and 2B , the related art in-line sputtering apparatus has a carrier  220  to transfer a substrate  210  into a chamber  200 . Then, unlike the aforementioned cluster type lifter  120 , the carrier  220  is not placed upright within the chamber  200 , but is moved in a direction perpendicular to a mask  240  of the chamber  200  to transfer the substrate  210  to a region facing a target  230 , thereby depositing a target material from the target  230  onto the substrate  210 . 
     However, even though the related art in-line type sputtering apparatus is suitable for the deposition process on a large-sized substrate, it is difficult to adjust a gap between the substrate  210  and the mask  240  to be smaller than 10 mm, because the carrier  220  is moved vertically to transfer the substrate  210  to a region facing the target material  230 . In other words, when the substrate  210  and the carrier  220  are moved vertically, they may be bent due to thermal deformation or the like, thereby causing a variation of an error range in uniformity of the substrate  210  and the carrier  220 . If the carrier  220  and the substrate  210  are transferred to the region facing the target material  230  regardless of such a variation, the substrate  210  and the mask  240  may have a gap greater than 10 mm in one region and smaller than 10 mm in another region, and may even contact each other. In the event that the substrate  210  and the mask  240  contact each other, the substrate  210  may be scratched by the mask  240  and thus contaminated, or the substrate  210  may be damaged by a collision with the mask  240 . Moreover, in the related art in-line sputtering apparatus, since the substrate  210  and the mask  240  have the gap as wide as approximately 10 mm, particles generated by a back sputtering contaminate the carrier  220 . 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a sputtering apparatus and a method of driving the same that substantially obviate one or more problems due to limitations and disadvantages of the related art. 
     An object of the present invention is to provide a sputtering apparatus and a driving method thereof capable of preventing particle contamination caused due to a contact between a mask and a carrier by maintaining a uniform gap therebetween regardless of deformation of a substrate. 
     Another object of the present invention is to provide a sputtering apparatus and a driving method thereof capable of preventing particle contamination caused due to back sputtering by minimizing a gap between a mask and a carrier. 
     Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a sputtering apparatus for depositing a target material on a substrate, which includes a chamber, a target including the target material in the chamber, a carrier to carry substrate into the chamber to face the target, and a plurality of masks arranged along sides of the carrier in the chamber and being movable back and forth with respect to the carrier. 
     In another aspect of the present invention, there is provided a method of driving a sputtering apparatus including a target for a target material, a carrier to carry a substrate to face the target in a chamber, and a plurality of masks arranged along sides of the carrier and being movable back and forth with respect to the carrier. The method includes transferring the carrier and the substrate in the chamber to face the target, moving the carrier and the substrate toward the target, moving each of the plurality of masks toward the carrier, and performing a sputtering process, thereby depositing the target material from the target onto the substrate. 
     In a further another aspect of the present invention, there is provided a sputtering apparatus for depositing a target material on a substrate, which includes a carrier to carry the substrate, a first chamber to measure a bending degree to which the carrier bends, and a second chamber including a target for the target material, a plurality of masks arranged along sides of the carrier and being movable back and forth with respect to the carrier, and a plurality of moving units to move the plurality of masks, wherein the plurality of masks are each movable individually depending on the bending degree of the carrier. 
     In a still further another aspect of the present invention, there is provided a method of driving a sputtering apparatus including a first chamber to measure a degree to which a carrier carrying a substrate bends, and a second chamber including a target for a target material, a plurality of masks arranged along sides of the carrier and being movable back and forth with respect to the carrier, and a plurality of moving units to move the plurality of masks, respectively. The method includes measuring the bending degree to which the carrier bends when the carrier and the substrate are transferred in the first chamber, transferring the carrier carrying the substrate from the first chamber to the second chamber, wherein the carrier is moved to face the target, moving the carrier toward the target, and moving each of the plurality of masks toward the carrier depending on the bending degree of the carrier. 
     It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG. 1  is a schematic cross-sectional view illustrating a cluster type sputtering apparatus according to the related art; 
         FIG. 2A  is a plan view schematically illustrating an in-line type sputtering apparatus according to the related art; 
         FIG. 2B  is a cross-sectional view schematically illustrating the related art in-line type sputtering apparatus within a chamber; 
         FIG. 3A  is a plan view schematically illustrating an in-line type sputtering apparatus according to an exemplary embodiment of the present invention; 
         FIG. 3B  is a cross-sectional view schematically illustrating an in-line type sputtering apparatus within a chamber according to the exemplary embodiment of the present invention; 
         FIG. 4  is a view schematically illustrating an exemplary arrangement of floating masks of  FIGS. 3A and 3B ; and 
         FIG. 5  is a plan view schematically illustrating an in-line type sputtering apparatus according to another exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
       FIG. 3A  is a plan view schematically illustrating an in-line type sputtering apparatus according to an exemplary embodiment of the present invention, and  FIG. 3B  is a cross-sectional view schematically illustrating the in-line type sputtering apparatus of  FIG. 3B . As shown in  FIG. 3A , the in-line type sputtering apparatus of the exemplary embodiment has a carrier  320  to transfer a substrate  310  into a process chamber  300 . Then, unlike the aforementioned cluster type lifter  120 , the carrier  320  is not placed upright within the process chamber  300 , but is moved in a direction perpendicular to a mask part MP of the chamber  300  to transfer the substrate  310  to a region facing a target  330 , thereby depositing a target material from the target  330  onto the substrate  310 . 
     According to this exemplary embodiment, the mask part MP includes a mask  342 , a plurality of floating masks  344  and a plurality of floating mask moving units  346 . After the completion of the vertical transfer of the carrier  320  in the process chamber  300 , the floating masks  344  may be moved toward the carrier  320 , thereby reducing a gap between the floating masks  344  and the carrier  320  as compared to the related art in-line type of  FIGS. 2A and 2B . Moreover,  FIG. 4  schematically illustrates an exemplary arrangement of the plurality of floating masks  344  of  FIG. 3 . As shown in  FIG. 4 , the floating masks  344  may further include first, second, third and fourth floating masks  344   a ,  344   b ,  344   c  and  344   d . In this exemplary embodiment, the four floating masks  344   a  to  344   d  are provided on four separated sides of the mask  342 , respectively. Alternatively, fewer or more floating masks may be used. 
     Referring to  FIG. 3B , the process chamber  300  of the exemplary sputtering apparatus includes a substrate part SP, a target part TP, and the mask part MP. As shown in  FIG. 3B , the target part TP includes a rear plate  314 , the target  330  attached to the rear plate  314 , and a magnet  318  provided behind the rear plate  314 . The magnet  318  supplies a magnetic field to prevent electrons generated in the plasma from undesirably coming out of a plasma generation region. The rear plate  314  serves to fix the target  330  that includes a target material to be deposited onto the substrate  310  by a sputtering process. Moreover, a cathode (not shown) may be provided between the target  330  and the rear plate  314 . The rear plate  314  may also serve as the cathode. 
     The substrate part SP includes the substrate  310  onto which the target material from the target  330  is to be deposited by the sputtering process, and the carrier  320  carrying the substrate  310 . An anode (not shown) may be provided between the substrate  310  and the carrier  320 . The carrier  320  may also serve as the anode. 
     As discussed above, the mask part MP includes the mask  342 , the floating masks  344  (e.g.,  344   a  to  344   d ), and the floating mask moving units  346 . The mask  342  is fixedly connected to the chamber  300 . The floating masks  344   a  to  344   d  are arranged corresponding to the four sides of the masks  342 , respectively, and are movable back and forth (i.e., backward and forward). The floating masks  344  are moved by the floating mask moving unit  346 . In this exemplary embodiment, as shown in  FIG. 3B , the forward direction is toward the carrier  320 , and the backward direction is away form the carrier  320 . 
     When the process of transferring the carrier  320  and the substrate  310  is finished, the carrier  320  is moved toward the target  330 . In this exemplary embodiment, the substrate  310  and the mask part MP have a gap of approximately 10 mm therebetween. A separate moving unit may be provided to move the carrier  320  toward the target  330 . Moreover, the floating mask moving units  346  may include first to fourth moving units, which correspond to the first to fourth floating masks  344   a  to  344   d  of  FIG. 4 , respectively. Moreover, the floating masks  344   a  to  344   d  may be individually driven or may be driven all together at the same time by the corresponding first to fourth moving units, respectively. According to such an arrangement of the exemplary embodiment, when the substrate  310  and the carrier  320  are bent due to thermal deformation, the floating masks  344   a ,  344   b ,  344   c  and  344   d  are separately adjusted to have the same gaps with the substrate  310  despite of the uniformity variations due to the bending of the substrate  310 . 
     The carrier  320  transferred and fixed to a region facing the target  330  is moved toward the target  330 , and the floating masks  344  are moved toward the carrier  320  by the floating mask moving unit  346 , thereby reducing a gap between the floating masks  344  and the carrier  320  as compared to the related art. For example, the gap between the floating masks  344  and the substrate  310  according to the exemplary embodiment is approximately 5 mm, whereas the gap between the mask and the substrate according to the related art is approximately 10 mm. 
     In the exemplary embodiment of the present invention, the gap between the floating masks  344  and the substrate  310  is reduced in the aforementioned manner, thereby preventing particle contamination due to the back sputtering. Also, a certain amount of gap therebetween is maintained, thereby avoiding the occurrence of particle contamination due to a contact between the floating masks  344  and the substrate  310 . Moreover, in the exemplary embodiment, a stable plasma generation system may be implemented in an in-line sputter by minimizing undesirable vibrations of the carrier  320  at the time of transfer thereof. 
     The floating mask moving units  346  may be driven by a motor or the like, thereby moving the respective floating masks  344 . Also, the floating mask moving units  346  may be controlled individually or together by a control unit (not shown) provided in the mask part MP. Moreover, the mask  342  may be formed in a quadrangular frame shape of a conductive material such as aluminum (Al) or the like, and generates plasma by maintaining the potential difference with the target  330  serving as a cathode. The floating masks  344  may be formed of a conductive material such as aluminum (Al) and may be electrically insulated from the mask  342 . 
     When the sputtering process is finished and the target material from the target  330  is deposited on the substrate  310  in a state where the floating masks  344  have been moved toward the substrate  310 , the floating masks  344  move back to their initial positions so that the floating masks  344  and the substrate  310  are spaced apart again by approximately 10 mm. Moreover, individual carriers may have different bending degrees depending on assembly differences, vacuum, thermal impact, or the like. 
       FIG. 5  is a plan view schematically illustrating an in-line type sputtering apparatus according to another exemplary embodiment of the present invention. As shown in  FIG. 5 , unlike the embodiment of  FIG. 3A , the in-line type sputtering apparatus according to this exemplary embodiment further includes a load chamber  400  in front of the process chamber  300  in which the sputtering is performed. 
     The load chamber  400  is provided with a carrier-bending measuring unit (not shown) that measures the degree to which a carrier  320  transferring a substrate  310  bends before the sputtering. That is, since a plurality of carriers  320  have different properties including different bending degrees, the bending degree of each carrier  320  is measured before the sputtering process. Accordingly, when the floating masks  344   a  to  344   d  are moved toward the carrier  320 , the degrees to which the floating masks  344   a  to  344   d  provided on the four sides of the mask  342  move are individually controlled. Herein, each carrier  320  may be identified by, for example, a bar code provided to the carrier  320 . 
     After the bending degree of the carrier  320  is measured in the load chamber  400  and the carrier  320  is transferred into the process chamber  300 , the remaining processes are the same as those illustrated in  FIG. 3B , and therefore, the detailed description thereon is omitted. 
     According to the exemplary embodiment of  FIG. 5 , when the floating masks  344   a  to  344   d  are moved toward the carrier  320 , the floating masks  344   a  to  344   d  may be moved to different degrees in consideration of the bending degree of the carrier  320 . That is, the floating-mask moving units  346  within the process chamber  300  are provided to correspond to the respective floating masks  344   a  to  344   d , and are separately moved by a control unit provided in the mask part MP depending on the measured bending degree of the carrier  320 . 
     As described so far, according to the exemplary embodiments of the present invention, a gap between a mask and a carrier within an in-line sputtering apparatus can be reduced, thereby preventing a target material from being unnecessarily deposited on the carrier and also avoiding contamination of the chamber and vibrations of transferring the carrier. Accordingly, a stable plasma generation system can be achieved in the in-line sputtering apparatus of the present invention. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the sputtering apparatus and the method of driving the sputtering apparatus of the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.