Abstract:
A plasma processing method and system including an apparatus and method for securing semiconductor hardware without the use of exposed threaded hardware. Consistent mechanical and electrical contact between parts in the assembled condition can also be achieved.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority to and is related to U.S. Provisional Application Ser. No. 60/450,351, filed on Feb. 28, 2003. The contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention is directed to an apparatus and method for securing semiconductor hardware, and more specifically to securing such hardware without the use of exposed threaded hardware.  
         [0004]     2. Discussion of the Background  
         [0005]     During the manufacturing and production of semiconductors, the use of plasma process chambers is sometimes necessary. Silicon wafers, providing a starting material for semiconductors, are loaded into chambers and exposed in various steps to process plasma.  
         [0006]     The plasma condition in process chambers can vary substantially, and many things can contribute to and subtract from the plasma generated. Process chambers contain multiple parts that affect plasma chemistry. Some of these parts are attached with common threaded fasteners. These fasteners, many times, can become a problem when generating particular plasmas because they may require hardware shielding after installation.  
         [0007]     A need exists for an attachment apparatus that minimizes the hardware necessary to assemble internal components of a plasma-processing chamber. Removal of parts secured with hardware, especially threaded hardware, is time consuming, requires hand or power tools and tends to create particles as the hardware is removed and subsequently replaced. Additional hardware increases time for procurement, inspection, cleaning, assembly and control.  
         [0008]     When installing parts using threaded hardware, consistent assembly is difficult to accomplish. To obtain consistent interface between parts, secured by threaded fasteners, the fasteners must be secured to specific torque requirements. This also requires additional tools. A need exists to consistently assemble internal plasma processing piece parts without special tools, process and inspections.  
         [0009]     The presence of metallic particles in a plasma process can, at times, be a significant problem. Many times, metallic hardware is shielded from the plasma to solve this problem. These shielding parts add additional parts required in the plasma tool. A need therefore exists for a way to attach parts in a plasma chamber so that shielding parts are not required or a shielding function is accomplished without adding extra parts.  
       SUMMARY OF THE INVENTION  
       [0010]     These and other problems are addressed by the present invention which provides an apparatus and method for attaching replaceable parts within a process chamber such that the need to clean the chamber is reduced.  
         [0011]     A first embodiment of the invention includes an external bayonet type interface between a first processing component and a second processing component.  
         [0012]     A second embodiment of the invention includes an internal bayonet type interface between a first processing component and a second processing component.  
         [0013]     A third embodiment of the invention utilizes two or more threaded fasteners used to mate a first processing component to a second processing component.  
         [0014]     A fourth embodiment of the invention uses two or more support pins, with various shaped support pin retainer assemblies that allow insertion and removal by hand. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     The above-noted and other aspects of the present invention will become more apparent from a detailed description of preferred embodiments when read in conjunction with the drawings, wherein:  
         [0016]      FIG. 1  is a cross-sectional view showing main components of a capacitively coupled plasma generating tool fastening system showing an external bayonet type interface between a ceramic insulator and a shield ring;  
         [0017]      FIG. 2  is a cross-sectional view of the external bayonet interface between a shield ring and a ceramic insulator;  
         [0018]      FIG. 3A  is a cross-sectional view of a support pin in external communication with a support pin groove of a ceramic insulator;  
         [0019]      FIG. 3B  is an alternate cross-sectional view of a support pin in communication with a support pin groove of a ceramic insulator;  
         [0020]      FIG. 4  is a cross-sectional view showing main components of a capacitively coupled plasma generating tool fastening system showing an internal bayonet type interface between a ceramic insulator and an inject plate;  
         [0021]      FIG. 5  is a cross-sectional view of the internal bayonet interface between the ceramic insulator and the inject plate;  
         [0022]      FIG. 6A  is a cross-sectional view of a support pin in internal communication with a support pin groove of a ceramic insulator;  
         [0023]      FIG. 6B  is an alternate cross-sectional view of a support pin in communication with a support pin groove of a ceramic insulator;  
         [0024]      FIG. 7  is a cross-sectional view of the main components of a capacitively coupled plasma generating tool fastening system showing a UEL plate—lower in communication with an inject plate through the use of a hardware attachment;  
         [0025]      FIG. 8  is a cut-away view of the fastening system of  FIG. 7 , a ceramic insulator, and an inject plate having a retaining groove and a groove counterbore;  
         [0026]      FIG. 9  is a cross-sectional view of the fastening system of  FIG. 7 ;  
         [0027]      FIG. 10  is a cross-sectional view of a plasma processing chamber utilizing a support pin retainer assembly which allows removal of support pins by hand;  
         [0028]      FIG. 11  is a cut-away cross-sectional view of the retainer assembly of  FIG. 10 ; and  
         [0029]      FIG. 12  is a cut-away plan view of the retainer assembly of  FIG. 10 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]      FIGS. 1, 2 ,  3 A and  3 B show an embodiment of a plasma process chamber  10  utilizing an external bayonet fastening apparatus  20  for coupling a first processing component with a second processing component. The plasma process chamber is typically configured such that an upper housing  30  is electrically insulated from an upper plate  40  of an upper electrode (UEL) and a lower plate  50  of the upper electrode by a ceramic insulator  60 . A shield ring  70  (e.g., a quartz shield ring) is positioned below the ceramic insulator  60 .  
         [0031]     The shield ring  70  is positioned inside the process chamber  10  underneath the upper housing  30 , ceramic insulator  60 , and an inject plate  80 . The shield ring  70  has two or more support pins  90  embedded therein and protruding toward the center of the process chamber  10 . The support pins may or may not be fabricated from the same material as the shield ring  70 .  
         [0032]     A support pin groove  100  in the ceramic insulator  60  is associated with each support pin  90  in the shield ring  70 . Each support pin groove  100  has a support pin receiving feature  110  which allows reception of a support pin  90 . Once support pins  90  are mounted in the support pin receiving feature  110 , rotation of the shield ring  70  is possible. Rotation of the shield ring  70  is accomplished until the support pins  90  contact a stop feature  120  in the support pin groove  100 . In order to access the shield ring  70  for installation, replacement, etc., the upper housing  30  is lifted away from the process chamber  10 . For example, the upper housing  30  can be coupled to the process chamber  10  via a hinge assembly (not shown), and the upper housing can be lifted away, as if it were a lid, to expose the shield ring  70  and the electrode plate  80 . Thereafter, the shield ring  70  can be removed and replaced by simply rotating and withdrawing the support pin  90  from the support pin receiving feature  110 .  
         [0033]     During rotation of the shield ring  70 , the support pins  90  travel along a support pin groove recess  130 . The support pin groove recess  130  has an upper surface  140  and a lower surface  150 .  
         [0034]      FIG. 3A  depicts a possible design of support pin groove  100 . The upper surface  140  and the lower surface  150  of the support pin groove recess  130  are approximately parallel to a bottom surface  170  of the ceramic insulator  60 .  
         [0035]     As shown in  FIG. 3B , a further possible design of support pin groove  100  is shown. The upper surface  140  and the lower surface  150  of the support pin groove recess  130  are set at an angle alpha to the bottom surface  170  of the ceramic insulator  60  which is not zero degrees. This angle can allow an axial force between the shield ring  70  and the ceramic insulator  60  when the shield ring  70  is rotated with respect to the ceramic insulator.  
         [0036]     Other embodiments of groove design are possible. Any types of groove shapes that allow a pin to move along during rotation are possible and are similar to the embodiments shown in  FIGS. 3A and 3B .  
         [0037]     An electrical contact device  160  (see  FIG. 2 ) can be positioned between the inject plate  80  and the lower UEL plate  50 . During rotation of the shield ring  70  the electrical contact device  160  is slightly deformed as it is captivated in its mounting groove. This deformation ensures consistent contact between the inject plate  80  and the lower UEL plate  50 .  
         [0038]      FIGS. 4, 5 ,  6 A and  6 B depict a further embodiment of a plasma process chamber  310  utilizing an internal bayonet type interface between a ceramic insulator  330  and an inject plate  340 . The plasma process chamber  310  is typically configured such that an upper housing  460  and process chamber liner  350  are electrically insulated from an upper UEL plate  360 , a lower UEL plate  370 , and the inject plate  340 .  
         [0039]     Two or more support pins  380  extend from the inject plate  340  outward from the center of the process chamber  310 . The support pins  380  are positioned so that they can engage the ceramic insulator  330 . A support pin groove  390  in the ceramic insulator  330  is associated with each support pin  380  in the inject plate  340 . Each support pin groove  390  has a support pin groove recess  410  which allows reception of a support pin  380 . This allows the inject plate  340  to be rotated and locked into the ceramic insulator  330 .  
         [0040]      FIG. 6A  depicts a possible embodiment of support pin groove  390 . The support pins  380  travel along a support pin groove recess  410 . The support pin groove  390  has an upper surface  420  and a lower surface  430 . The upper surface  420  and the lower surface  430  of support pin groove  390  are approximately parallel to the bottom surface  450  of the ceramic insulator  330 .  
         [0041]      FIG. 6B  depicts a further possible embodiment of support pin grove  390 . The upper surface  420  and the lower surface  430  of the support pin groove recess  410  are set an angle beta to the bottom surface  450  of the ceramic insulator  330  which is not zero degrees. This angle beta can allow an axial force between the lower UEL plate  370  and the ceramic insulator  330 , as the inject plate  340  is rotated with respect to the ceramic insulator  330 .  
         [0042]     Other embodiments of groove design are possible. Any types of groove shapes that allow a pin to move along during rotation are possible and are similar to the embodiments shown in  FIGS. 6A and 6B .  
         [0043]     An electrical contact device  440  can be positioned between the inject plate  340  and the lower UEL plate  370 . During rotation of the inject plate  340  the electrical contact device  440  is slightly deformed. This deformation ensures consistent contact between the inject plate  340  and the lower UEL plate  370 .  
         [0044]      FIGS. 7, 8 , and  9  represent yet another embodiment of the present invention wherein two or more threaded fasteners are used to fasten an inject plate  500  to a lower UEL electrode  510 .  
         [0045]     With reference to  FIG. 7 , a cross-sectional cut-away view of a plasma processing chamber is depicted. The lower UEL electrode  510  is fastened to an inject plate  500  through the use of a variable height pin  530 . The variable height pin  530  can be a threaded fastener or some other type of pin which can be adjusted in height.  
         [0046]     The variable height pin  530  is anchored in the lower UEL plate  510  such that a portion of the pin is left exposed and extending toward the bottom of the process chamber  540 . Although not limited thereto, the variable height pin  530  can be any kind of threaded fastener. The depth of the variable height pin  530  can be adjusted precisely by rotation. The exposed portion of the variable height pin  530  has an enlarged portion  520 . The enlarged portion  520  of the pin  530  is at least larger in cross-sectional area than the cross-sectional area of the rest of the variable height pin  530 . Rotation is accomplished with a slot or similar mating feature located in the inject plate  500  (see  FIG. 8 ). The enlarged portion  520  can be conically shaped.  
         [0047]     With reference to  FIG. 8 , the inject plate  500  possesses at least one mating feature  550  which receives the enlarged portion  520  of variable height pin  530 . The mating feature  550  is comprised of a groove counterbore  560  and a retaining groove  570 . The groove counterbore  560  is configured such that the diameter thereof is larger than the widest section of the enlarged portion  520 . The retaining groove  570  is configured such that the width of the retaining groove  570  is smaller than the widest section of the enlarged portion  520 . When the inject plate  500  positioned such that the counterbore  560  is in line with the enlarged portion  520 , the enlarged portion  520  is inserted into the counterbore  560  and the inject plate  500  is rotated to captivate the enlarged portion  520 , thereby maintaining communication of the inject plate  500  with the lower UEL electrode  510 .  
         [0048]     An electrical contact device  580  can be present in the lower UEL plate  510 . During rotation of the inject plate  500 , the electrical contact device  580  is slightly deformed. This deformation ensures consistent contact between the inject plate  500  and the lower UEL electrode  510 .  
         [0049]      FIG. 9  presents an alternative embodiment wherein the enlarged portion  520  has a rectangular shape rather than a conical shape.  
         [0050]      FIGS. 10, 11 , and  12  represent a further embodiment of the present invention which utilizes two or more support pins  740  with various shaped support pin retainer assemblies  720  that allow insertion, locking, and removal of the support pins  740  by hand.  
         [0051]      FIG. 10  depicts a cross-sectional view of a process chamber  700 . A ceramic insulator  710 , located within the process chamber  700 , is positioned in communication with a retainer body  720 . The retainer body  720  is positioned adjacent an inject assembly  730 . A retaining pin  740  is juxtaposed therebetween to ensure communication between the retainer body  720  and the inject assembly  730  is maintained. As can be seen in  FIG. 11 , the retaining pin  740  extends from the retainer body  720  passing through the ceramic insulator  710  to the inject plate  730 . Recess holes (not shown) are provided in both the ceramic insulator  710  and the inject assembly  730  through which the retaining pin  740  can be inserted.  
         [0052]     As depicted in  FIG. 12 , the retainer body  720  is positioned between a shield ring  750  and the inject plate  730 . The ceramic insulator  710  has a recess  760 . The recess  760  allows for insertion and removal of the retaining pin  740 .  
         [0053]     Although several embodiments have described the coupling between a ceramic insulator and a shield ring, a ceramic insulator and an inject plate, and an inject plate and an upper electrode, it should be understood that other embodiments are possible as well. For example, the mating/retaining features described herein can be utilized for coupling a first processing component to a second processing component. A processing component can include a focus ring, a shield ring coupled to a lower electrode, a deposition shield, a chamber liner, etc.