Abstract:
An exemplary gas supply system, includes a plurality of first input lines for supplying gas, a plurality of second input lines, a plurality of third input lines, a first mixing tank communicating with the second input lines, a second mixing tank communicating with the third input lines, and a plurality of three-way valves. Each three-way valve is communicated with a first input line, a second input line and a third input line such that gas in the first input lines can be selectively introduced into the first mixing tank or the second mixing tank.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to sputtering apparatuses, and particularly, to a gas supply system and a sputtering apparatus including the gas supply system. 
     2. Description of Related Art 
     Sputtering technology has been widely employed for improving surface properties of workpieces. In a conventional sputtering process, a number of film layers are formed layer by layer on a workpiece positioned in a sputtering chamber. Prior to forming each film layer, different gases are mixed in a tank for obtaining a mixed reactive gas, and then the mixed reactive gas enters the sputtering chamber. 
     However, two film layers are usually formed in different mixed reactive gas atmosphere occurring within the sputtering chamber. It requires significant time to mix the reactive gases before forming an upper film on a lower film. As a result, the sputtering process is interrupted to wait for the reactive gases to mix, which decreases sputtering efficiency. Therefore, a gas supply system and a sputtering apparatus having the same are desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the present gas supply system and the sputtering apparatus can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present system and the apparatus. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the views. 
         FIG. 1  is an isometric view of a sputtering apparatus having a gas supply system in accordance with a first embodiment. 
         FIG. 2  is an isometric view of another sputtering apparatus having a gas supply system in accordance with a second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a sputtering apparatus  100  includes a first sputtering chamber  10 , a second sputtering chamber  20 , a conveyor device  30 , and a gas supply system  40 . 
     The conveyor device  30  is configured for conveying workpieces from the first sputtering chamber  10  to the second sputtering chamber  20 . A door  50  is arranged between the first sputtering chamber  10  and the second sputtering chamber  20 . Thereby, when the door  50  is open, workpieces can be conveyed from the first sputtering chamber  10  into the second sputtering chamber  20 . 
     The two sputtering chambers each includes a target  11  positioned on a top wall  13  thereof. Additionally, the two sputtering chambers respectively define an inert gas inlet  12  in the top wall  13 . 
     The gas supply system  40  includes three first input lines  41 , three three-way valve  54 , three second input lines  42 , three third input lines  43 , a first mixing tank  56 , a first output line  44 , a second mixing tank  57  and a second output line  45 . 
     Each first input line  41  includes a reactive gas source  51 , a first valve  53 , a mass flow controller (MFC)  52  arranged therein in that order. The reactive gas source  51  is configured for providing reactive gas for sputtering process. In the present embodiment, the three reactive gas sources  51  respectively provide nitrogen gas, acetylene gas, and oxygen gas. Each first input line  41  intersects with a corresponding second input line  42  and a corresponding third input line  43  at a corresponding three-way valve  54 . That means the second input lines  42  are in parallel connection with the third input lines  43 . 
     The three second input lines  42  and the first output line  44  communicate with the first mixing tank  56 . The three third input lines  43  and the second output line  45  communicate with the second mixing tank  57 . Each second input line  42  includes a second valve  55  arranged between the corresponding three-way valve  54  and the first mixing tank  56 . Each third input line  43  includes a third valve  60  arranged between the corresponding three-way valve  54  and the second mixing tank  57 . In this manner, each reactive gas source  51  is capable of alternately supplying reactive gas into the first mixing tank  10  or the second mixing tank  20 . 
     A fourth valves  59  is respectively arranged in the first output line  44  and the second output line  45 . The first output line  44  communicates with the first sputtering chamber  10 , while the second output line  45  communicates with the second sputtering chamber  20 . In addition, a pump  58  is employed for pumping mixed gas out of the first mixing tank  56  or the second mixing tank  57 . 
     In actual use, for instance, in a sputtering process, three different kinds of reactive gases are first supplied from the three reactive gas sources  51 , then flow into the first mixing tank  56  under a control of a corresponding MFC  52  and a three-way valve  54 . Thereby, a first mixed gas is obtained in the first mixing tank  56 . The fourth valve  59  is subsequently opened, the first mixed gas flows into the first sputtering chamber  10 . An inert gas is applied into the first sputtering chamber  10 . Thus, a lower film can be formed on a workpiece in the first sputtering chamber  10 . Meanwhile, the three first input lines  41  communicate with the third input lines  43  under a control of the three three-way valves  54 . It is understood that three different kinds of reactive gases flow into the second mixing tank  57 , and a second mixed gas is obtained. When finishing forming the lower film on the workpiece, the workpiece immediately enters into the second sputtering chamber  20 . The fourth valve  59  between the second mixing tank  57  and the second sputtering chamber  20  is opened, and the second mixed gas flows into the second sputtering chamber  20 . Thereby, an upper film can be formed on the lower film of the workpiece. Meanwhile, the first input lines  41  are controlled to communicate with the second input lines  42 , and three different kinds of reactive gases simultaneously flow into the first mixing tank  56 . In this way, the first and second mixing tank  56 ,  57  alternately supply mixed reactive gas. Time for mixing reactive gases is saved and the sputtering apparatus  100  is continuously operated. 
     If few first mixed gas is retained in the first mixing tank  56  after forming the lower film on the workpiece, the second valves  55  in the second input lines  42  and the third valve  59  in the first output line  44  are simultaneously shut off, and the pump  58  pumps the retained first mixed gas out of the first mixing tank  56 . And then, three gas sources begin to supply reactive gases into the first mixing tank  56 . 
     Referring to  FIG. 2 , another sputtering apparatus  200  provided in a second embodiment includes a gas supply system  240  and a sputtering chamber  250  including a target  270  positioned on a top wall thereof. 
     The gas supply system  240  has similar configuration with that of the gas supply system  40 , and includes three first input lines  241 , three three-way valves  254 , three second input lines  242 , a first mixing tank  256 , three third input lines  243 , a second mixing tank  257 , a first output line  244  and a second output line  245 . A reactive gas source  251 , a first valves  253 , a MFC  252  are arranged in each of the three first input lines  241  in that order. 
     Additionally, a check valve  260  is arranged between a corresponding MFC  252  and a corresponding three-way valve  254 . The check valve  260  prevents the mixed reactive gas in the first mixing tank  256  or the second mixing tank  257  from reflowing into the MFC  252 . 
     Furthermore, a third output line  246  is included. The first output line  244  intersects with the second output line  245  at the third output line  246 . The third output line  246  communicates with the sputtering chamber  250 . 
     It is understood that the above-described embodiments are intended to illustrate rather than limit the disclosure. Variations may be made to the embodiments and methods without departing from the spirit of the disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the disclosure.