Patent Document

FIELD  
         [0001]    The subject matter herein generally relates to the field of switches.  
         DESCRIPTION OF RELATED ART  
         [0002]    Radio frequency switches perform numerous switching cycles over their lifetime. Some radio frequency switches may operate, in part, by contact between two metal contacts. Over time, the surface(s) of the contacts may wear down. Wear may subject the switch to stiction, whereby contacts of the switch adhere to one another during contact. Stiction may slow the rate at which switch operations may be performed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0003]    [0003]FIG. 1 depicts in cross section a switch, in accordance with an embodiment of the present invention.  
         [0004]    [0004]FIG. 2 depicts one possible process that may be used to construct the switch of FIG. 1, in accordance with an embodiment of the present invention.  
         [0005]    FIGS.  3  to  11  depict in cross section various stages of fabrication of the switch of FIG. 1, in accordance with an embodiment of the present invention.  
         [0006]    [0006]FIG. 12 depicts in cross section a switch, in accordance with an embodiment of the present invention.  
         [0007]    [0007]FIG. 13 depicts one possible process that may be used to construct the switch of FIG. 12, in accordance with an embodiment of the present invention.  
         [0008]    FIGS.  14  to  22  depict in cross section various stages of fabrication of the switch of FIG. 12, in accordance with an embodiment of the present invention.  
         [0009]    [0009]FIG. 23 depicts in cross section a switch, in accordance with an embodiment of the present invention.  
         [0010]    [0010]FIG. 24 depicts one possible process that may be used to construct the switch of FIG. 23, in accordance with an embodiment of the present invention.  
         [0011]    FIGS.  25  to  33  depict in cross section various stages of fabrication of the switch of FIG. 23, in accordance with an embodiment of the present invention.  
         [0012]    [0012]FIG. 34 depicts in cross section a switch, in accordance with an embodiment of the present invention.  
         [0013]    [0013]FIG. 35 depicts one possible process that may be used to construct the switch of FIG. 34, in accordance with an embodiment of the present invention.  
         [0014]    FIGS.  35  to  44  depict in cross section various stages of fabrication of the switch of FIG. 34, in accordance with an embodiment of the present invention. 
     
    
       [0015]    Note that use of the same reference numbers in different figures indicates the same or like elements.  
       DETAILED DESCRIPTION  
       [0016]    [0016]FIG. 1 
         [0017]    [0017]FIG. 1 depicts in cross section a switch  100 , in accordance with an embodiment of the present invention. Switch  100  may include base  110 , arm  170 A, contact  175 , second contact  120 C, and actuation  120 B. Base  110  may support second contact  120 C and arm  170 A. When a voltage is applied between actuation  120 B and arm  170 A, arm  170 A may lower contact  175  to contact with second contact  120 C. In accordance with an embodiment of the present invention, second contact  120 C may have a durable protective coating layer  140 C that may protect second contact  120 C from wear.  
         [0018]    In accordance with an embodiment of the present invention, FIG. 2 depicts one possible process that may be used to construct the switch  100  depicted in FIG. 1. Action  210  includes providing metal layer  120  over silicon surface  110 . FIG. 3 depicts in cross section an example structure that may result from action  210 . A suitable implementation of silicon surface  110  is a silicon wafer. Suitable materials of layer  120  include gold and/or aluminum. A suitable technique to provide metal layer  120  includes sputter deposition or physical vapor deposition. A suitable thickness of layer  120  is approximately ½ to 1 micron.  
         [0019]    Action  220  includes providing adhesion layer  130  over metal layer  120 . FIG. 4 depicts in cross section an example structure that may result from action  220 . Suitable materials of layer  130  include titanium, molybdenum, and/or tungsten. A suitable technique to provide metal layer  130  includes sputter deposition or physical vapor deposition. A suitable thickness of layer  130  is approximately 0.1 micron.  
         [0020]    Action  230  includes providing protective layer  140  over layer  130 . FIG. 5 depicts in cross section an example structure that may result from action  230 . Suitable materials of protective layer  140  include, but are not limited to, diamond, rhodium, ruthenium, and/or diamond-like carbon film. A suitable technique to provide protective layer  140  includes plasma enhanced chemical vapor deposition (CVD). A suitable thickness of layer  140  is approximately 100 to 500 angstroms.  
         [0021]    Action  240  includes removing portions of layers  120  to  140  to form stacks  145 A,  145 B, and  145 C. Each of stacks  145 A,  145 B, and  145 C includes portions of layers  120  to  140 . FIG. 6 depicts in cross section an example structure that may result from action  240 . A suitable distance between stacks  145 A and  145 B (along the X axis) is approximately 5 to 50 microns. Layer  120 B of stack  145 B may be referred to as actuation  120 B. A suitable distance between stacks  145 B and  145 C (along the X axis) is approximately 1 to 10 microns. In action  240 , a suitable technique to remove portions of layers  120  to  140  includes: (1) applying a mask to portions of the exposed surface of layer  140  that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) to remove portions of layer  140 , etch layer  140  by reactive ion etching or oxygen plasma; (4) to remove layers  120  and  130 , using fluorinated hydrocarbons (e.g., CF 4  or C 2 F 6 ), or a combination of nitric acid with sulfuric acid; and (5) removing polymerized resist by using a resist stripper solvent.  
         [0022]    Action  250  includes providing sacrificial layer  150  over the structure depicted in cross section in FIG. 6. FIG. 7 depicts in cross section an example structure that may result from action  250 . Suitable materials of layer  150  include SiO 2 , polymer, glass-based materials, and/or metals (e.g., copper). Suitable techniques to provide layer  150  include (1) sputtering, chemical vapor deposition (CVD), spin coating, or physical vapor deposition followed by (2) polishing a surface of layer  130  using e.g., chemical mechanical polish (CMP). A suitable thickness of layer  150  is approximately 1 micron over stacks  145 A,  145 B, and  145 C.  
         [0023]    Action  260  includes removing a portion of layer  150  and portions of layers  130 A and  140 A of stack  145 A from the structure depicted in FIG. 7. FIG. 8 depicts in cross section an example structure that may result from action  260 . From side  155  of structure depicted in FIG. 7, a suitable distance is 10 to 30 microns along the X axis to remove portion of layer  150  and portions of layers  130 A and  140 A of stack  145 A. A suitable technique to implement action  260  includes: (1) applying a mask to portions of the exposed surface of layer  150  that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) to remove layer  150 , providing an HF solution; (4) to remove layer  140 A, etch layer  140 A by reactive ion etching or oxygen plasma; (5) to remove layer  130 A, providing fluorinated hydrocarbons (e.g., CF 4  or C 2 F 6 ), or a combination of nitric acid with sulfuric acid; and (6) removing polymerized resist by using a resist stripper solvent. Hereafter, re-shaped layer  150  is referred to as layer  150 A.  
         [0024]    Action  270  includes removing dimple region  160  from layer  150 A. FIG. 9 depicts in cross section an example structure that may result from action  270 . Dimple region  160  may be dome shaped. A suitable technique to implement action  270  includes: (1) providing a mask over portions of the exposed surface of layer  150 A that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) to remove a dimple region of layer  150 A, etch layer  150 A by reactive ion etching to a depth of approximately ½ micron; and (4) removing polymerized resist by using a resist stripper solvent.  
         [0025]    Action  280  includes providing metal conductive layer  170  in dimple region  160  and over the structure shown in FIG. 9. FIG. 10 depicts in cross section an example structure that may result from action  280 . A suitable material of metal conductive layer  170  includes gold and/or aluminum. Layer  170  may be the same material but does not have to be the same material as that of metal layer  120 . A suitable technique to provide layer  170  includes sputter deposition or physical vapor deposition. A suitable thickness of layer  170  is 2 to 4 microns. Dimple contact  175  may thereby be formed from the portion of metal conductive layer  170  that fills dimple region  160 .  
         [0026]    Action  290  includes removing a portion of layer  170  up to a distance of approximately 2 to 8 microns (along the X axis) from side  172  of the structure depicted in FIG. 10. FIG. 11 depicts in cross section an example structure that may result from action  290 . A suitable technique to remove a portion of layer  170  includes: (1) applying a mask to portions of the exposed surface of layer  170  that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) using fluorinated hydrocarbons (e.g., CF 4  or C 2 F 6 ), or a combination of nitric acid with sulfuric acid; and (4) removing polymerized resist by using a resist stripper solvent. Hereafter the re-shaped layer  170  is hereafter referred to as layer or arm  170 A.  
         [0027]    Action  295  includes removing a remaining sacrificial layer  150 A. FIG. 1 depicts in cross section an example structure that may result from action  295 . A suitable technique to remove remaining sacrificial layer  150 A includes submerging the structure depicted in FIG. 11 into an HF solution.  
         [0028]    [0028]FIG. 12 
         [0029]    [0029]FIG. 12 depicts in cross section a switch  300 , in accordance with an embodiment of the present invention. Switch  300  may include base  310 , arm  370 A, actuation  320 B, first contact  365 , and second contact  320 C. When an electric field is applied between actuation  320 B and arm  370 A, then contact  365  may lower to contact second contact  320 C. In accordance with an embodiment of the present invention, first contact  365  may have a durable coating layer that may protect first contact  365  from wear.  
         [0030]    In accordance with an embodiment of the present invention, FIG. 13 depicts one possible process that may be used to construct the switch  300  depicted in FIG. 12. Action  410  includes providing metal layer  320  over silicon surface  310 . FIG. 14 depicts in cross section an example structure that may result from action  410 . A suitable implementation of silicon surface  310  is a silicon wafer. Suitable materials of layer  320  include gold and/or aluminum. A suitable technique to provide metal layer  320  includes sputter deposition or physical vapor deposition. A suitable thickness of layer  320  is approximately ½ to 1 micron.  
         [0031]    Action  420  includes removing portions of layer  320  to form layers  320 A,  320 B and  320 C. FIG. 15 depicts in cross section an example structure that may result from action  420 . A suitable distance between layers  320 A and  320 B (along the X axis) is approximately 5 to 50 microns. A suitable distance between layers  320 B and  320 C (along the X axis) is approximately 1 to 10 microns. A suitable technique to remove portions of layer  320  includes: (1) applying a mask to portions of the exposed surface of layer  320  that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) applying fluorinated hydrocarbons (e.g., CF 4  or C 2 F 6 ), or a combination of nitric acid with sulfuric acid; and (4) removing polymerized resist by using a resist stripper solvent. Herein, layer  320 B may otherwise by referred to as actuation  320 B whereas layer  320 C may otherwise be referred to as second contact  320 C.  
         [0032]    Action  430  includes providing a sacrificial layer  330  over the structure depicted in cross section in FIG. 15. FIG. 16 depicts in cross section an example structure that may result from action  430 . Suitable materials of layer  330  include SiO 2 , polymer, glass-based materials, and/or metals (e.g., copper). Suitable techniques to provide layer  330  include (1) sputtering, chemical vapor deposition (CVD), or physical vapor deposition followed by (2) polishing a surface of layer  330  using e.g., chemical mechanical polishing (CMP). Suitable thickness of layer  330  over layers  320 A,  320 B and  320 C (along the Y axis) is approximately 1 micron.  
         [0033]    Action  440  includes forming an anchor region in sacrificial layer  330 . FIG. 17 depicts in cross section an example structure that may result from action  440 . From side  335  of the structure depicted in cross section in FIG. 16, a suitable distance along the X axis to remove portion of layer  330  is 10 to 30 microns. A suitable technique to implement action  440  includes: (1) applying a mask to portions of the exposed surface of layer  330  that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) to remove layer  330 , providing an HF solution; and (4) removing polymerized resist by using a resist stripper solvent. Hereafter, re-shaped layer  330  may be referred to as layer  330 A.  
         [0034]    Action  450  includes removing dimple region  340  from layer  330 A. FIG. 18 depicts in cross section an example structure that may result from action  450 . Dimple region  340  may be dome shaped. A suitable technique to implement action  450  includes: (1) providing a mask over portions of the exposed surface of layer  330 A that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) to remove a dimple region from layer  330 A, etch layer  330 A by reactive ion etching to a depth of approximately ½ micron; and (4) removing polymerized resist by using a resist stripper solvent.  
         [0035]    Action  460  includes providing protective layer  350  over structure depicted in FIG. 18. FIG. 19 depicts in cross section an example structure that may result from action  460 . Suitable materials of protective layer  350  include, but are not limited to, diamond, rhodium, ruthenium, and/or diamond-like carbon film. A suitable technique to provide protective layer  350  includes plasma enhanced chemical vapor deposition (CVD). Suitable thickness of layer  350  is approximately 100 to 500 angstroms.  
         [0036]    Action  470  includes providing adhesion layer  360  over the structure depicted in cross section in FIG. 19. FIG. 20 depicts in cross section an example structure that may result from action  470 . Suitable materials of layer  360  include titanium, molybdenum, and/or tungsten. A suitable technique to provide metal layer  360  includes sputter deposition or physical vapor deposition. A suitable thickness of layer  360  is approximately 0.1 micron.  
         [0037]    Action  480  includes providing a second metal conductive layer  370  over the structure depicted in cross section in FIG. 20. FIG. 21 depicts in cross section an example structure that may result from action  480 . A suitable material of the second metal conductive layer  370  includes gold and/or aluminum. A suitable techniques to provide layer  370  include sputter deposition or physical vapor deposition. A suitable thickness of layer  370  is approximately 2 to 4 microns. Herein, reshaped layer  370  is referred to as arm  370 A. Herein, a portion of dimple region  340  filled with second metal conductive layer  370  is otherwise referred to as first contact  365 .  
         [0038]    Action  490  includes removing a portion of layers  350 - 370  up to a distance of approximately 2 to 8 microns (along the X axis) from side  375 . FIG. 22 depicts in cross section an example structure that may result from action  490 . A suitable technique to implement action  490  includes: (1) applying a mask to portions of the exposed surface of layer  370  that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) to remove a portion of layers  360  and  370 , using fluorinated hydrocarbons (e.g., CF 4  or C 2 F 6 ), or a combination of nitric acid with sulfuric acid; (4) to remove a portion of layer  350 , using reactive ion etching or oxygen plasma; and (5) removing polymerized resist by using a resist stripper solvent.  
         [0039]    Action  495  includes removing a remaining sacrificial layer  330 A. FIG. 12 depicts in cross section an example structure, switch  300 , that may result from action  495 . A suitable technique to remove remaining sacrificial layer  330 A includes submerging structure depicted in FIG. 22 into an HF solution.  
         [0040]    [0040]FIG. 23 
         [0041]    [0041]FIG. 23 depicts in cross section a switch  500 , in accordance with an embodiment of the present invention. Switch  500  may include base  505 , actuation  525 A, arm  555 , contacts  535 B to  535 E. Contacts  535 B to  535 E may be attached to base  505 . When an electric field is applied between actuation  525 A and arm  555 , arm  555  may lower towards contacts  535 B to  535 E and may be capable of establishing a conductive connection with contacts  535 B to  535 E. In accordance with an embodiment of the present invention, contacts  535 B to  535 E may include a durable coating layer that may protect contacts  535 B to  535 E from wear.  
         [0042]    In accordance with an embodiment of the present invention, FIG. 24 depicts one possible process that may be used to construct the switch  500  depicted in FIG. 23. Action  610  includes forming SiO 2  layer  520 A on a silicon layer  510 . A suitable implementation of silicon layer  510  is a silicon wafer. A suitable thickness of SiO 2  layer  520 A is approximately 0.2 to 1 micron. Action  615  includes forming a metal layer  525  over SiO 2  layer  520 A. A suitable thickness of metal layer  525  is approximately 0.2 to 1 micron. A suitable material of metal layer  525  includes gold and/or aluminum. A suitable technique to provide metal layer  525  includes (1) sputter deposition or physical vapor deposition and (2) etch to remove portions of metal layer  525  to form the actuation  525 A. FIG. 25 depicts in cross section a structure that may result from actions  610  and  615 .  
         [0043]    Action  620  includes forming a second SiO 2  layer  520 B over the structure depicted in cross section in FIG. 25. A suitable thickness of the second SiO 2  layer  520 B is approximately 2 to 4 microns over actuation  525 A. FIG. 26 depicts in cross section a structure that may result from action  620 . Herein, base  505  may refer to a combination of layers  510 ,  520 A, and  520 B as well as actuation  525 A.  
         [0044]    Action  625  includes providing second metal layer  535  over the structure shown in cross section in FIG. 26. FIG. 27 depicts in cross section a structure that may result from action  625 . Suitable materials of second metal layer  535  include gold and/or aluminum. A suitable technique to provide second metal layer  535  includes sputter deposition or physical vapor deposition. Suitable thickness of second metal layer  535  is approximately ½ to 1 micron.  
         [0045]    Action  630  includes providing adhesion layer  540  over second metal layer  535 . FIG. 28 depicts in cross section a structure that may result from action  630 . Suitable materials of layer  540  include titanium, molybdenum, and/or tungsten. A suitable technique to provide metal layer  540  includes sputter deposition or physical vapor deposition. A suitable thickness of layer  540  is approximately 0.1 micron.  
         [0046]    Action  635  includes providing protective layer  543  over layer  540 . FIG. 29 depicts in cross section a structure that may result from action  635 . Suitable materials of protective layer  543  include, but are not limited to, diamond, rhodium, ruthenium, and/or diamond-like carbon film. A suitable technique to provide protective layer  543  includes plasma enhanced chemical vapor deposition (CVD). A suitable thickness of layer  543  is approximately 100 to 500 angstroms.  
         [0047]    Action  640  includes removing portions of layers  535 ,  540 , and  543  to form stacks  545 A- 545 F. FIG. 30 depicts in cross section a structure that may result from action  640 . Each of stacks  545 A- 545 F includes portions of layers  535 ,  540 , and  543 . A suitable distance between stacks  545 A and  545 B (along the X axis) is approximately 20 to 80 microns. A suitable distance between stacks  545 B and  545 C (along the X axis) is approximately 2 to 10 microns. A suitable distance between stacks  545 C and  545 D (along the X axis) is approximately 2 to 10 microns. A suitable distance between stacks  545 D and  545 E (along the X axis) is approximately 2 to 10 microns. A suitable distance between stacks  545 E and  545 F (along the X axis) is approximately 20 to 80 microns. A suitable technique to remove portions of layers  535 ,  540 , and  543  includes: (1) applying a mask to portions of the exposed surface of layer  543  that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) to remove layer  543 , etch layer  543  by reactive ion etching or oxygen plasma; (4) to remove layers  535  and  540 , using fluorinated hydrocarbons (e.g., CF 4  or C 2 F 6 ), or a combination of nitric acid with sulfuric acid; and (5) removing polymerized resist by using a resist stripper solvent.  
         [0048]    Action  645  includes providing sacrificial layer  550  over, for example, the structure depicted in cross section in FIG. 30. FIG. 31 depicts in cross section a structure that may result from action  645 . Suitable materials of layer  550  include SiO 2 , polymer, glass-based materials, and/or metals (e.g., copper). Suitable techniques to provide layer  550  include (1) sputtering, chemical vapor deposition (CVD), or physical vapor deposition followed by (2) polishing the surface of sacrificial layer  550  using e.g., chemical mechanical polish (CMP). A suitable thickness of layer  550  (along the Y axis) is approximately 1 micron over stacks  545 A- 545 F.  
         [0049]    Action  650  includes removing a portion of layer  550  and portions of layers  540  and  543  of layers  545 A and  545 F from the structure depicted in cross section in FIG. 31. FIG. 32 depicts in cross section a structure that may result from action  650 . From side  551  of the structure of FIG. 31, a suitable distance along the X axis to remove portion of layer  550  and layers  540  and  543  of layer  545 A is approximately 10 to 30 microns. From side  553  of the structure depicted in cross section in FIG. 31, a suitable distance along the X axis to remove portion of layer  550  and layers  540  and  543  of layer  545 F is approximately 10 to 30 microns. A suitable technique to implement action  650  includes: (1) applying a mask to portions of the exposed surface of layer  550  that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) to remove layer  550 , providing an HF solution; (4) to remove layer  543 , etch layer  540 A by reactive ion etching or oxygen plasma; (5) to remove layer  540 , providing fluorinated hydrocarbons (e.g., CF 4  or C 2 F 6 ), or a combination of nitric acid with sulfuric acid; and (6) removing polymerized resist by using a resist stripper solvent.  
         [0050]    Action  655  includes providing a third metal conductive layer  555  over, for example, the structure depicted in cross section in FIG. 32. FIG. 33 depicts in cross section a structure that may result from action  655 . A suitable material of third metal conductive layer  555  includes gold and/or aluminum. A suitable techniques to provide third metal conductive layer  555  include sputter deposition or physical vapor deposition. Suitable thickness of layer  555  is approximately 1 to 5 microns. Herein, layer  555  may be referred to as arm  555 .  
         [0051]    Action  660  includes removing the remaining sacrificial layer  550 . FIG. 23 depicts in cross section a structure that may result from action  660 . A suitable technique to remove remaining sacrificial layer  550  includes submerging the structure depicted in cross section in FIG. 33 into an HF solution.  
         [0052]    [0052]FIG. 34 
         [0053]    [0053]FIG. 34 depicts in cross section a switch  700  in accordance with an embodiment of the present invention. Switch  700  may include base  705 , actuation  725 A, arm  770 , contacts  735 B to  735 E. Contacts  735 B to  735 E may be attached to base  705 . When an electric field is applied between actuation  725 A and arm  770 , arm  770  may lower towards contacts  735 B to  735 E and may be capable of establishing a conductive connection with contacts  735 B to  735 E. In accordance with an embodiment of the present invention, a surface of arm  770  which may contact contacts  735 B to  735 E may include a durable coating that may protect arm  770  from wear.  
         [0054]    In accordance with an embodiment of the present invention, FIG. 35 depicts one possible process that may be used to construct the switch  700  depicted in FIG. 34. Action  810  includes forming SiO 2  layer  720 A over silicon layer  710 . A suitable implementation of silicon layer  710  is a silicon wafer. A suitable thickness of SiO 2  layer  720 A is approximately 0.2 to 1 micron.  
         [0055]    Action  815  includes forming metal layer  725 A over SiO 2  layer  720 A. A suitable material of metal layer  725 A includes gold and/or aluminum. A suitable technique to provide metal layer  725  includes (1) sputter deposition or physical vapor deposition of a metal layer and (2) etch to remove portions of metal layer  725  to form metal layer  725 A. A suitable thickness of metal layer  725 A is 0.2 to 1 micron. FIG. 36 depicts in cross section a structure that may result from actions  810  and  815 . Herein, base  705  may refer to a combination of layers  710 ,  720 A, and  720 B as well as actuation  725 A. Herein, actuation  725 A may refer to metal layer  725 A.  
         [0056]    Action  820  includes forming SiO 2  layer  720 B over structure depicted in cross section in FIG. 36. A suitable thickness of SiO 2  layer  720 B is approximately 2 to 4 microns over actuation  725 A. FIG. 37 depicts in cross section a structure that may result from action  
         [0057]    Action  825  includes providing metal layer  735  over the structure shown in cross section in FIG. 37. FIG. 38 depicts in cross section a structure that may result from action  825 . Suitable materials of layer  735  include gold and/or aluminum. A suitable technique to provide metal layer  735  includes sputter deposition or physical vapor deposition. A suitable thickness of layer  735  is approximately ½ to 1 micron.  
         [0058]    Action  830  includes removing portions of layer  735  to form layers  735 A- 735 F. FIG. 39 depicts in cross section a structure that may result from action  830 . A suitable distance between layers  735 A and  735 B (along the X axis) is approximately 20 to 80 microns. A suitable distance between layers  735 B and  735 C (along the X axis) is approximately 2 to 10 microns. A suitable distance between layers  735 C and  735 D (along the X axis) is approximately 2 to 10 microns. A suitable distance between layers  735 D and  735 E (along the X axis) is approximately 2 to 10 microns. A suitable distance between layers  735 E and  735 F (along the X axis) is approximately 20 to 80 microns. A suitable technique to remove portions of layer  735  includes: (1) applying a mask to portions of the exposed surface of layer  735  that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) using fluorinated hydrocarbons (e.g., CF 4  or C 2 F 6 ), or a combination of nitric acid with sulfuric acid; and (4) removing polymerized resist by using a resist stripper solvent.  
         [0059]    Action  835  includes providing a sacrificial layer  740  over the structure depicted in cross section in FIG. 39. FIG. 40 depicts in cross section a structure that may result from action  835 . Suitable materials of layer  740  include SiO 2 , polymer, glass-based materials, and/or metals (e.g., copper). Suitable techniques to provide layer  740  include (1) sputtering, chemical vapor deposition (CVD), or physical vapor deposition followed by (2) polishing the surface of sacrificial layer  740  using e.g., chemical mechanical polish (CMP). A suitable thickness of layer  740  (along the Y axis) over layers  735 A- 735 F is approximately 0.5 to 2 microns.  
         [0060]    Action  840  includes removing portions of layer  740  from the structure depicted in cross section in FIG. 40. FIG. 41 depicts in cross section a structure that may result from action  840 . From side  741  of structure of FIG. 40, a suitable distance along the X axis to remove a portion of layer  740  is approximately 10 to 30 microns. From side  742  of structure of FIG. 40, a suitable distance along the X axis to remove a portion of layer  740  is approximately 10 to 30 microns. A suitable technique to implement action  840  includes: (1) applying a mask to portions of the exposed surface of layer  740  that are not to be removed; (2) photolithography to polymerize the mask (thereby forming a polymerized resist); (3) to remove layer  740 , providing an HF solution; and (4) removing polymerized resist by using a resist stripper solvent. Hereafter, re-shaped layer  740  is referred to as layer  740 A.  
         [0061]    Action  845  includes providing protective layer  750  over the structure depicted in cross section in FIG. 41. FIG. 42 depicts in cross section a structure that may result from action  845 . Suitable materials of protective layer  750  include, but are not limited to, diamond, rhodium, ruthenium, and/or diamond-like carbon film. A suitable technique to provide protective layer  750  includes plasma enhanced chemical vapor deposition (CVD). A suitable thickness of layer  750  is approximately 100 to 500 angstroms.  
         [0062]    Action  850  includes providing adhesion layer  760  over the structure depicted in cross section in FIG. 42. FIG. 43 depicts in cross section a structure that may result from action  850 . Suitable materials of layer  760  include titanium, molybdenum, and/or tungsten. A suitable technique to provide metal layer  760  includes sputter deposition or physical vapor deposition. Suitable thickness of layer  760  is approximately 0.1 micron.  
         [0063]    Action  855  includes providing third metal conductive layer  770  over the structure shown in cross section in FIG. 43. FIG. 44 depicts in cross section a structure that may result from action  855 . A suitable material of metal conductive layer  770  includes gold and/or aluminum. Suitable techniques to provide layer  770  include sputter deposition or physical vapor deposition. A suitable thickness of layer  770  is approximately 1 to 5 microns.  
         [0064]    Action  860  includes removing remaining sacrificial layer  740 A. FIG. 34 depicts in cross section a structure that may result from action  860 . A suitable technique to remove remaining sacrificial layer  740 A includes submerging structure depicted in cross section in FIG. 44 into an HF solution.  
         [0065]    Modifications  
         [0066]    The drawings and the forgoing description gave examples of the present invention. The scope of the present invention, however, is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. Process actions may be combined and performed at the same time. The scope of the invention is at least as broad as given by the following claims.

Technology Category: 5