Patent Publication Number: US-2007119700-A1

Title: Apparatus and method for manufacturing a multilayer film

Description:
TECHNICAL FIELD  
      The present invention relates to apparatuses and methods for manufacturing a multilayer film; and more particularly to an apparatus for manufacturing a multilayer film having good wear resistance and stable chemical and mechanical characteristics, and a method for manufacturing the multilayer film.  
     BACKGROUND  
      Diamond-like carbon films have similar characteristics to diamond, such as high hardness, a low friction coefficient, and high chemical stability. Therefore diamond-like carbon films are used in equipment such as molds, where the diamond-like carbon film serves as a protection layer to improve corrosion resistance and wear resistance. A diamond-like carbon film formed on a mold is generally a single layer created by a direct current sputtering process. This kind of diamond-like carbon film commonly has poor wear resistance. When the mold is repeatedly used many times, the diamond-like carbon film may easily detach or even peel off from the base surface of the mold. When this happens, the mold has lower corrosion resistance and reduced wear resistance.  
      What is needed, therefore, is an apparatus for manufacturing a multilayer film that has good wear resistance and stable chemical and mechanical characteristics. What is also needed is a method for manufacturing the multilayer film.  
     SUMMARY  
      In one embodiment, an apparatus for manufacturing a multilayer film includes a sputtering system. The sputtering system includes a first sputtering chamber, a nitrogen-doping sputtering chamber, a nitrogen and hydrogen-doping sputtering chamber, and a hydrogen-doping sputtering chamber connected to each other in that order. The first sputtering chamber is configured with two targets and at least one inert gas. The nitrogen-doping sputtering chamber is configured with a carbon-doped target and at least one inert gas. The nitrogen and hydrogen-doping sputtering chamber is configured with a carbon-doped target and at least one inert gas. The hydrogen-doping sputtering chamber is configured with a carbon-doped target and at least one inert gas. Adjacent sputtering chambers have at least one valve configured therebetween.  
      In another embodiment, a method for manufacturing a multilayer film includes: providing a substrate; forming a nanometer adhesive layer on surface of the substrate by an alternating current magnetron sputtering method; forming a nanometer intermediate layer on the adhesive layer by an alternating current magnetron sputtering method; forming a nitrogen-doped diamond-like carbon layer on the intermediate layer by an alternating current magnetron sputtering method; forming a nitrogen and hydrogen-doped diamond-like carbon layer on the nitrogen-doped diamond-like carbon layer by an alternating current magnetron sputtering method; and forming a hydrogen-doped diamond-like carbon layer on the nitrogen and hydrogen-doped diamond-like carbon by an alternating current magnetron sputtering method.  
      Other advantages and novel features will become more apparent from the following detailed description of various embodiments of the present apparatus and method for manufacturing a multilayer film when taken in conjunction with the accompanying drawings.  
    
    
     BRIEF DESCRIPTION OF THE 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 apparatus and method. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.  
       FIG. 1  is a schematic, side cross-sectional view of an article that includes a multilayer film formed on a substrate in accordance with embodiments of the present invention.  
       FIG. 2  is a schematic diagram of an apparatus for manufacturing the film on the substrate shown in  FIG. 1 , in accordance with a first embodiment of the present invention.  
       FIG. 3  is a schematic view of another apparatus for manufacturing the film on the substrate shown in  FIG. 1 , in accordance with a second embodiment of the present invention.  
       FIG. 4  is a flowchart of a method for manufacturing a film on a substrate such as the film on the substrate shown in  FIG. 1 , in accordance with a third embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
      Reference will now be made to the drawing figures to describe in detail preferred embodiments of the present apparatus and method for manufacturing a multilayer film.  
      Referring to  FIG. 1 , an article  1  with a multilayer film  10  formed in accordance with embodiments of the present invention is shown. The article  1  includes a substrate  20 , and the film  10  formed on the substrate  20 . The film  10  includes a transition layer  11 , a nitrogen-doped diamond-like carbon layer  12 , a nitrogen and hydrogen-doped diamond-like carbon layer  13 , and a hydrogen-doped diamond-like carbon layer  14  stacked in that order from bottom to top. The transition layer  11  includes an adhesive layer  111  and an intermediate layer  112 .  
      The substrate  20  can for example be a precursor base of a mold. In other examples, a variety of equipment or products may include the substrate  20  having the film  10  formed thereon. A material of the adhesive layer  111  is selected from the group consisting of chrome, titanium, and chrome titanium. A thickness of the adhesive layer  111  is in the range from 1 nanometer to 20 nanometers. A material of the intermediate layer  112  is selected from the group consisting of chromium nitride, titanium nitride, and a mixture thereof. A thickness of the intermediate layer  112  is in the range from 1 nanometer to 50 nanometers.  
      The nitrogen-doped diamond-like carbon layer  12  has stable chemical and mechanical characteristics. The hydrogen-doped diamond-like carbon layer  14  has a low friction coefficient and good wear resistance. The film  10  resists detachment or peeling off from the substrate  20  because of the adhesive layer  111 .  
      Referring to  FIG. 2 , an apparatus  200  for manufacturing the film  10  in accordance with a first embodiment of the present invention is shown. The apparatus  200  includes a sputtering system and a transmission system  26 .  
      The sputtering system includes a first vacuum chamber  211 , a second vacuum chamber  212 , a third vacuum chamber  213 , a fourth vacuum chamber  214 , and a fifth vacuum chamber  215  connected to each other in that order. A respective sputtering chamber (see below) is configured between each two adjacent of the vacuum chambers  211 ˜ 215 . A vacuum pump  27  is provided with each sputtering chamber.  
      A first sputtering chamber  221  is configured between the first vacuum chamber  211  and the second vacuum chamber  212 , and is used to sputter the transition layer  11 . A first target  231  is provided in the first sputtering chamber  221  for sputtering the adhesive layer  111 , and a second target  232  is provided in the first sputtering chamber  221  for sputtering the intermediate layer  112 . A blocking plate  2211  is provided in the first sputtering chamber  221  for selectively blocking the first target  231  or the second target  232 . A material of the first target  231  is selected from the group consisting of chrome, titanium, and chrome titanium. A material of the second target  232  is selected from the group consisting of chromium nitride, titanium nitride, and a mixture thereof.  
      At least one valve is configured between the first sputtering chamber  221  and each adjacent vacuum chamber  211 ,  212 . During a sputtering process carried out in the first sputtering chamber  221 , each vacuum chamber  211 ,  212  is utilized as a buffer. The first vacuum chamber  211  has two valves  2111 ,  2112 . When the valve  2111  is open, the vacuum chamber  211  is open to an outside of the apparatus  200 . When the valve  2112  is open, the vacuum chamber  211  is open to the first sputtering chamber  221 .  
      The first sputtering chamber  221  contains at least one inert gas therein. The at least one inert gas is selected from the group consisting of argon gas and krypton gas.  
      A nitrogen-doping sputtering chamber  222  having a carbon-doped target  233  therein is configured between the second vacuum chamber  212  and the third vacuum chamber  213 . The sputtering chamber  222  contains nitrogen gas in the range from 2% to 40% by volume.  
      A nitrogen and hydrogen-doping sputtering chamber  223  having a carbon-doped target  234  therein is configured between the third vacuum chamber  213  and the fourth vacuum chamber  214 . The sputtering chamber  223  contains nitrogen gas in the range from 2% to 10% by volume, and a gas containing the element hydrogen. The gas containing the element hydrogen is present in the range from 5% to 15% by volume, and is selected from the group consisting of hydrogen gas, methane, and ethane.  
      A hydrogen-doping sputtering chamber  224  having a carbon-doped target  235  therein is configured between the fourth vacuum chamber  214  and the fifth vacuum chamber  215 . The sputtering chamber  224  contains a gas containing the element hydrogen. The gas containing the element hydrogen is present in the range from 5% to 20% by volume, and is selected from the group consisting of hydrogen gas, methane, and ethane.  
      As with the first sputtering chamber  221 , at least one valve is configured between each sputtering chamber  222 ,  223 ,  224  and each respective adjacent of the vacuum chambers  212 ,  213 ,  214 ,  215 . As with the first sputtering chamber  221 , each sputtering chamber  222 ,  223 ,  224  contains at least one inert gas therein. The at least one inert gas is selected from the group consisting of argon gas and krypton gas.  
      A pressure within each sputtering chamber  221 ˜ 224  is equal to or less than 10 pascal. A material of the carbon-doped targets  233 ,  234 ,  235  is selected from the group consisting of graphite and carbon.  
      The transmission system  26  is used to move a carrier  25  therealong. The carrier  25  is for holding the substrate  20 . The substrate  20  is put onto the carrier  25 . Thus the transmission system  26  can move the substrate  20  along through the first vacuum chamber  211 , the first sputtering chamber  221 , and so on through to the fifth vacuum chamber  215  of the sputtering system as required, and then take the substrate  20  out from the sputtering system. In this first embodiment, the transmission system  26  includes a number of rollers  261  configured for moving the carrier  25  along a same direction. The transmission system  26  can further or alternatively include a transmission belt.  
      Referring to  FIG. 3 , another apparatus  300  for manufacturing the film  10  in accordance with a second embodiment of the present invention is shown. The apparatus  300  includes four sputtering chambers  310 ,  320 ,  330 ,  340  connected to each other in that order.  
      Each two adjacent of the sputtering chambers  310 ˜ 340  are interconnected via at least one respective valve  370 . The sputtering chamber  310  is open to an outside of the apparatus  300  through at least another valve  370 , and the sputtering chamber  340  is open to an outside of the apparatus  300  through at least still another valve  370 . The sputtering chamber  310  is used to sputter the transition layer  11 . The sputtering chamber  310  has a first target  311  and a second target  312  therein. The first target  311  is used to sputter the adhesive layer  111 , and the second target  312  is used to sputter the intermediate layer  112 . The sputtering chamber  310  has a blocking plate  313  therein, for selectively blocking the first target  311  or the second target  312 .  
      The sputtering chamber  320  has a carbon-doped target  321  and nitrogen gas therein, and is used to sputter the nitrogen-doped diamond-like carbon layer  12 . The sputtering chamber  330  has a carbon-doped target  331  and nitrogen gas and gas containing the element hydrogen therein, and is used to sputter the nitrogen and hydrogen-doped diamond-like carbon layer  13 . The sputtering chamber  340  has a carbon-doped target  341  and gas containing the element hydrogen therein, and is used to sputter the hydrogen-doped diamond-like carbon layer  14 .  
      Each sputtering chamber  310 ˜ 340  also has a vacuum pump  360  for evacuating the sputtering chamber  310 ˜ 340 . The apparatus  300  further includes a transmission system  350 , which is used to move a carrier  35  therealong. The carrier  35  is for holding the substrate  20 . The substrate  20  is put onto the carrier  35 . Thus the transmission system  350  can move the substrate  20  along through the sputtering chambers  310 ˜ 340  as required, and then take the substrate  20  out from the sputtering chamber  340 . In this second embodiment, the transmission system  350  includes a number of rollers  351  configured for moving the carrier  35  along a same direction. The transmission system  350  can further or alternatively include a transmission belt.  
      In an alternative embodiment, the targets  311 ,  312  can be configured in two separate sputtering chambers, instead of the one sputtering chamber  310 .  
      Referring to  FIG. 4 , a method for manufacturing a film such as the film  10  using the apparatus  300  in accordance with a third embodiment of the present invention is shown. The method is described in detailed as follows:  
      In step  1 , a substrate such as the substrate  20  is provided. The substrate  20  can for example be a precursor base of a mold. In other examples, a variety of equipment or product precursors may include the substrate  20  for having the film  10  formed thereon.  
      In step  2 , a nanometer adhesive layer such as the adhesive layer  111  is formed on a surface of the substrate  20  by an alternating current magnetron sputtering method. The end valve  370  of the sputtering chamber  310  is opened, and the substrate  20  is put onto the transmission system  350 . The end valve  370  of the sputtering chamber  310  and the valve  370  between the sputtering chamber  310  and the sputtering chamber  320  are closed. During the sputtering process, the substrate  20  is functions as an anode and the first target  311  functions as a cathode. An alternating current is applied between the anode and the cathode. Therefore, the inert gas in the sputtering chamber  310  is ionized. Inert gas ions strike the first target  311 , and atoms of the first target  311  are deposited on the substrate  20 . The blocking plate  313  blocks the second target  312  when the adhesive layer  111  is being sputtered.  
      In step  3 , a nanometer intermediate layer such as the intermediate layer  112  is formed on the adhesive layer  111  by an alternating current magnetron sputtering method that is similar to the alternating current magnetron sputtering method of step  2 . The blocking plate  313  blocks the first target  311 , and then the intermediate layer  112  is formed by sputtering the second target  312 . The valve  370  between the sputtering chambers  310 ,  320  is opened, and the substrate is moved into the sputtering chamber  320  by the transmission system  350 .  
      In step  4 , a nitrogen-doped diamond-like carbon layer such as the nitrogen-doped diamond-like carbon layer  12  is formed on the intermediate layer  112  by an alternating current magnetron sputtering method that is similar to the alternating current magnetron sputtering method of steps  2  or  3 . In the sputtering chamber  320 , a reactive alternating current sputtering process takes place. The nitrogen gas chemically reacts with the target  321 , and nitrogen-doped matter is generated. The nitrogen-doped matter is deposited on the intermediate layer  112  as nitrogen-doped diamond-like carbon. The valve  370  between the sputtering chambers  320 ,  330  is opened, and the substrate  20  is moved into the sputtering chamber  330  by the transmission system  350 .  
      In step  5 , a nitrogen and hydrogen-doped diamond-like carbon layer such as the nitrogen and hydrogen-doped diamond-like carbon layer  13  is formed on the nitrogen-doped diamond-like carbon layer  12  by an alternating current magnetron sputtering method that is similar to the alternating current magnetron sputtering method of step  4 . In the sputtering chamber  330 , a reactive alternating current sputtering process takes place. Nitrogen gas and gas containing the element hydrogen chemically react with the target  331 , and nitrogen-doped matter and hydrogen-doped matter are generated. The nitrogen-doped matter and hydrogen-doped matter are deposited on the nitrogen-doped diamond-like carbon layer  12  as nitrogen and hydrogen-doped diamond-like carbon. The valve  370  between the sputtering chambers  330 ,  340  is opened, and the substrate  20  is moved into the sputtering chamber  340  by the transmission system  350 .  
      In step  6 , a hydrogen-doped diamond-like carbon layer such as the hydrogen-doped diamond-like carbon layer  14  is formed on the nitrogen and hydrogen-doped diamond-like carbon layer  13  by an alternating current magnetron sputtering method that is similar to the alternating current magnetron sputtering method of steps  4  or  5 . In the sputtering chamber  340 , a reactive alternating current sputtering process takes place. Gas containing the element hydrogen chemically reacts with the target  341 , and hydrogen-doped matter is generated. The hydrogen-doped matter is deposited on the nitrogen and hydrogen-doped diamond-like carbon layer  13  as hydrogen-doped diamond-like carbon. The valve  370  of the sputtering chamber  340  is opened, and the substrate  20  is taken out of the apparatus  300 . Thus, the film  10  formed on the substrate  20  is obtained.  
      Although the present invention has been described with reference to specific embodiments, it should be noted that the described embodiments are not necessarily exclusive, and that various changes and modifications may be made to the described embodiments without departing from the scope of the invention as defined by the appended claims and equivalents thereof.