Apparatus and method for multi-zone high-density inductively-coupled plasma generation

Abstract

A multi-zone high-density inductively-coupled plasma source includes a first individually controlled RF antenna segment for producing a plasma from a process gas. A second individually controlled coil segment is included in the ICP source for producing a plasma from a process gas. In various embodiments, more than two sets of individually controlled coil segments may be used. In one embodiment, a separate power supply may be used for each coil segment individually. Another aspect of this invention is a hermetically-sealed inductively-coupled plasma source structure and method of fabrication which eliminates the possibility of process contamination, improves the source hardware reliability and functionality, and improves the vacuum integrity and ultimate base pressure of the plasma system.

What is claimed is:  
     
         1 . A multi-zone inductively-coupled plasma source, for producing a plasma medium comprising: 
 a first antenna structure for substantially inductive coupling of radio-frequency electrical power to said plasma medium;    at least one additional antenna structure for inductive coupling of additional radio-frequency electrical power to said plasma medium, wherein said first antenna structure and said at least one additional antenna structure are operated together for providing a substantially uniform plasma process on at least one substrate placed in a low-pressure plasma processing equipment.    
     
     
         2 . The inductively-coupled plasma source of    claim 1   , further comprising; 
 a plurality of radio-frequency power supplies operable to supply power to said antenna structures; and    a real-time multi-variable controller operable to control the plurality of radio frequency power supplies in order to provide a substantially uniform plasma process.    
     
     
         3 . The inductively-coupled plasma source of    claim 1   , further comprising; 
 a plurality of radio-frequency power supplies operable to supply power to said antenna structures; and    a scalar controller with pre-specified power supply power ratios operable to control the plurality of radio frequency power supplies in order to provide a substantially uniform plasma process.    
     
     
         4 . The inductively-coupled plasma source of    claim 1    wherein said first antenna structure comprises at least one antenna segment made of an electrically conducting material.  
     
     
         5 . The inductively-coupled plasma source of    claim 1    wherein said first antenna structure comprises at least two antenna segments made of an electrically conducting material and further wherein said at least two antenna segments are connected in series via at least one series capacitor.  
     
     
         6 . The inductively-coupled plasma source of    claim 5    wherein said at least one series capacitor is operable to reduce the induced radio-frequency voltage across said first antenna structure.  
     
     
         7 . The inductively-coupled plasma source of    claim 6    wherein said first antenna segment is shaped as a substantially circular broken ring.  
     
     
         8 . The inductively-coupled plasma source of    claim 1    wherein said at least one additional antenna structure comprises at least one antenna segment made of an electrically conducting material.  
     
     
         9 . The inductively-coupled plasma source of    claim 1    wherein said at least one additional antenna structure comprises at least two antenna segments made of an electrically conducting material and further wherein said at least two antenna segments are connected in series via at least one series capacitor.  
     
     
         10 . The inductively-coupled plasma source of    claim 9    wherein said at least one series capacitor is operable to reduce the induced radio-frequency voltage across said at least one additional antenna structure.  
     
     
         11 . The inductively-coupled plasma source of    claim 4    wherein each of said at least one antenna additional segment has a shape of a substantially circular broken ring.  
     
     
         12 . The inductively-coupled plasma source of    claim 1    wherein said radio-frequency electrical power and said additional radio-frequency electrical power are supplied by a single radio-frequency power supply.  
     
     
         13 . The inductively-coupled plasma source of    claim 12    further comprising a plurality of adjustable capacitors operable to connect said antenna structures in parallel to said single radio-frequency power supply.  
     
     
         14 . The inductively-coupled plasma source of    claim 12    wherein said radio-frequency power supply further comprises a radio-frequency matching network operable to maximize radio-frequency power coupling efficiency to said antenna structures.  
     
     
         15 . The inductively-coupled plasma source of    claim 12    further comprising an adjustable transformer coupling device operable coupled to the single radio-frequency power supply, and wherein said adjustable transformer coupling device coupling parameters are adjusted by a multi-variable controller in order to establish a substantially uniform plasma process on said at least one substrate.  
     
     
         16 . The inductively-coupled plasma source of    claim 15    wherein said radio-frequency power supply further comprises a radio-frequency matching network in order to maximize the radio-frequency power coupling efficiency to said antenna structures.  
     
     
         17 . The inductively-coupled plasma source of    claim 1    wherein said first antenna structure and said at least one additional antenna structure provide a capability to control plasma density values in different regions of said plasma medium.  
     
     
         18 . The inductively-coupled plasma source of    claim 13    wherein said adjustable capacitors are set according to pre-specified values in order to establish a substantially uniform plasma process on said at least one substrate.  
     
     
         19 . The inductively-coupled plasma source of    claim 13    wherein said adjustable capacitors are adjusted by a multi-variable controller in order to establish a substantially uniform plasma process on said at least one substrate.  
     
     
         20 . The inductively-coupled plasma source of    claim 15    wherein said adjustable transformer coupling device coupling parameters are set according to pre-specified values in order to establish a substantially uniform plasma process on said at least one substrate.  
     
     
         21 . The inductively-coupled plasma source of    claim 1    wherein said radio-frequency electrical power and said additional radio-frequency power are supplied by at least two separate radio-frequency power supplies.  
     
     
         22 . The inductively-coupled plasma source of    claim 21    wherein said at least two separate radio-frequency power supplies are adjusted according to pre-specified power set points in order to establish a substantially uniform plasma process on said at least one substrate.  
     
     
         23 . The inductively-coupled plasma source of    claim 21    wherein said at least two separate radio-frequency power supplies are adjusted by a multi-variable controller in order to establish a substantially uniform plasma process on said at least one substrate.  
     
     
         24 . The inductively-coupled plasma source of    claim 1    wherein said plasma processing equipment is a semiconductor device manufacturing equipment.  
     
     
         25 . The inductively-coupled plasma source of    claim 1    wherein said plasma processing equipment is a data storage device manufacturing equipment.  
     
     
         26 . The inductively-coupled plasma source of    claim 1    wherein said first antenna structure comprises a substantially planar antenna.  
     
     
         27 . The inductively-coupled plasma source of    claim 1    wherein said at least one additional antenna structure comprises a substantially planar antenna.  
     
     
         28 . The inductively-coupled plasma source of    claim 1    wherein said first antenna structure comprises a cylindrical antenna and wherein said at least one additional antenna structure comprises a cylindrical antenna.  
     
     
         29 . The inductively-coupled plasma source of    claim 1    wherein said first antenna structure comprises a conic antenna and wherein said at least one additional antenna structure comprises a conic antenna.  
     
     
         30 . The inductively-coupled plasma source of    claim 1    wherein said first antenna structure comprises a graded structure antenna and wherein said at least one additional antenna structure comprises a graded structure antenna.  
     
     
         31 . The inductively-coupled plasma source of    claim 1    wherein said first antenna structure and said at least one additional antenna structure are embedded in a protective housing made of an electrically insulating material.  
     
     
         32 . The inductively-coupled plasma source of    claim 31    wherein said protective housing is coupled to a vacuum support component providing vacuum real to process chamber of said plasma processing equipment.  
     
     
         33 . The inductively-coupled plasma source of    claim 31    wherein said protective housing comprises a thermally conducting material.  
     
     
         34 . The inductively-coupled plasma source of    claim 31    wherein said electrically insulating material is a ceramic-based material.  
     
     
         35 . The inductively-coupled plasma source of    claim 34    wherein said ceramic-based material comprises aluminum nitride.  
     
     
         36 . The inductively-coupled plasma source of    claim 31    wherein said electrically insulating material is a polymer-based material.  
     
     
         37 . The apparatus of    claim 1   , further comprising: 
 a first RF power supply for providing RF power to said first antenna structure; and    at least one separate RF power supply for providing RF power to said at least one additional antenna structure;    said first RF power supply and said at least one separate RF power supply being associated to achieve uniform plasma process on said at least one substrate in said plasma processing equipment.    
     
     
         38 . The apparatus of    claim 37   , wherein said first RF power supply and said at least one separate RF power supply operate independently for providing multi-RDMP process control flexibility and uniformity adjustment during a plasma fabrication process.  
     
     
         39 . The apparatus of    claim 1   , further comprising; 
 a first RF power supply for providing RF power to said first antenna structure; and    at least one separate RF power supply for providing RF power to said at least one additional antenna structure;    said first RF power supply and said at least one separate RF power supply being associated to achieve spatially uniform plasma density and ion current density in said plasma processing equipment.    
     
     
         40 . The inductively-coupled plasma source of    claim 1    wherein said antenna structures comprise a plurality of inductive coil segments with various sizes a spatial positions selected to provide a substantially uniform plasma process on said at least one substrate with a specified substrate size.  
     
     
         41 . The inductively-coupled plasma source of    claim 1    wherein said inductive coil segments are formed as substantially concentric broken circular rights with various diameters.  
     
     
         42 . The inductively-coupled plasma source of    claim 1    wherein said inductive coil segments ring breaks are angularly staggered.  
     
     
         43 . The inductively-coupled plasma source of    claim 1    further comprising an optical viewport for real-time plasma process monitoring using an in-situ sensor in said plasma processing equipment.  
     
     
         44 . The inductively-coupled plasma source of    claim 43    wherein said in-situ sensor is a plasma emission sensor.  
     
     
         45 . The inductively-coupled plasma source of    claim 43    wherein said in-situ sensor is a full-wafer interferometry sensor.  
     
     
         46 . The inductively-coupled plasma source of    claim 31    wherein said protective housing comprises an upper dielectric plate and a lower dielectric plate.  
     
     
         47 . The inductively-coupled plasma source of    claim 46    wherein said upper dielectric plate comprises feedthroughs for providing electrical connections to said antenna structures.  
     
     
         48 . The inductively-coupled plasma source of    claim 47    wherein said upper dielectric plate further comprises at least one process gas inlet feedthrough and at least one gas dispersion cavity associated with said process gas inlet feedthrough.  
     
     
         49 . The inductively-coupled plasma source of    claim 48    wherein said lower dielectric plate comprises cavities to house said antenna structures.  
     
     
         50 . The inductively-coupled plasma source of    claim 49    wherein said lower dielectric plate further comprises a plurality of small diameter holes for injecting a process gas from said at least one gas dispersal cavity.  
     
     
         51 . The inductively-coupled plasma source of    claim 31    wherein said protective housing is a substantially planar assembly.  
     
     
         52 . The inductively-coupled plasma source of    claim 51    wherein said protective housing is a substantially cylindrical assembly with a diameter larger than said at least one substrate size.  
     
     
         53 . The inductively-coupled plasma source of    claim 9    wherein said at least one series capacitor connecting said at least two antenna segments is placed outside said plasma processing equipment vacuum chamber.  
     
     
         54 . The inductively-coupled plasma source of    claim 1    wherein said antenna structures have circular antenna segments.  
     
     
         55 . The inductively-coupled plasma source of    claim 1    wherein said antenna structures have spiral antenna segments.  
     
     
         56 . The inductively-coupled plasma source of    claim 1    wherein said radio frequency electrical power and said additional radio-frequency electrical power have electrical frequencies in the range of 1 MHZ to 50 MHZ.  
     
     
         57 . The inductively-coupled plasma source of    claim 1    wherein said radio-frequencies electrical power and said additional radio-frequency electrical power have equal electrical frequencies.  
     
     
         58 . The inductively-coupled plasma source of    claim 1    wherein said antenna structures provide spatial resolution and control capability within said plasma medium for establishing a multi-zone adjustment capability for plasma process parameters at said at least one substrate.  
     
     
         59 . A method for producing a multi-zone inductively-coupled plasma in a plasma processing equipment, comprising the steps of: 
 producing a plasma from a plasma process gas using a first inductively-coupled antenna structure;    separately producing a plasma from a plasma process gas using at least one additional inductively-coupled antenna structure; and    operating said first antenna structure in concert with at least one additional antenna structure to establish a substantially uniform plasma process on at least one substrate in said plasma processing equipment.    
     
     
         60 . The method of    claim 59   , further comprising the steps of: 
 providing radio frequency electrical power to said first inductively-coupled antenna structure using a first radio frequency power supply;    providing radio frequency electrical power to said at least one additional inductively-coupled antenna structure using at least one separate radio frequency power supply;    associating said first radio frequency power supply and said at least one separate radio frequency power supply for achieving uniform plasma processing on said at least one substrate.    
     
     
         61 . The method of    claim 60   , further comprising the steps of independently operating and adjusting said first radio frequency power supply and said at least one separate radio frequency power supply to provide process control flexibility and uniformity adjustment during a plasma process.  
     
     
         62 . The method of    claim 59   , further comprising the steps providing radio frequency power to said first inductively-coupled antenna structure and to said at least one additional inductively-coupled antenna structure using a single radio frequency power supply.  
     
     
         63 . The method of    claim 62   , wherein the step of providing radio frequency power using a single radio frequency power supply further comprises adjustably delivering electrical power levels from said single radio frequency power supply through at least two adjustable passive electrical components.  
     
     
         64 . The method of    claim 63   , further comprising the step of independently operating and adjusting the set points for said adjustable passive electrical components to establish a substantially uniform plasma process.  
     
     
         65 . The method of    claim 62   , wherein the step of providing radio frequency power using a single radio frequency power supply further comprises placing a transformer with adjustable-coupling sections between said single radio frequency power supply and said first inductively-coupled antenna structure.  
     
     
         66 . The method of    claim 65   , further comprising the step of independently operating said transformer and adjusting said adjustable-coupling sections to establish a substantially uniform plasma process.  
     
     
         67 . The method of    claim 59   , further comprising the steps of controlling said at least one additional inductively-coupled antenna structure to operate as a plurality of individual sets of inductively coupled antenna segments sized according to the size of said at least one substrate in said plasma processing equipment.  
     
     
         68 . The method of    claim 59   , further comprising the step of minimizing electric field induced arcing in said plasma processing equipment by reducing radio frequency voltage across said first inductively-coupled antenna structure and said at least one additional antenna structure by means of distributed resonant capacitors in said first inductively-coupled antenna structure and said at least one additional antenna structure.  
     
     
         69 . The method of    claim 59   , further comprising the steps of providing real-time multi-zone control of said first inductively-coupled antenna structure and said at least one additional inductively-coupled antenna structure using at least one in situ sensor to probe said plasma processing equipment to establish a substantially uniform plasma process.  
     
     
         70 . The method of    claim 60   , further comprising the step of sending a control signal provided by a sensor to a multi-variable controller to adjust the power supplied by the first radio frequency power supply and the power supplied by the at least one additional radio frequency power supply on a run-by-run basis.  
     
     
         71 . The method of    claim 60   , further comprising the step of sending a control signal provided by a sensor to a multi-variable controller to adjust the power supplied by the first radio frequency power supply and the power supplied by the at least one additional radio frequency power supply on a real time basis.  
     
     
         72 . A method for forming a multi-zone high-density inductively-coupled plasma source, comprising the steps of: 
 forming a first set of inductively coupled coil segments for producing a plasma from a plasma process gas; and    forming at least one separate set of inductively-coupled coil segments for separately producing a plasma from a plasma process gas, said first set of individually controlled inductively-coupled coil segments and said at least one separate set of inductively coupled coil segments associated for spatially resolved multi-zone operation to establish a substantially uniform plasma process.    
     
     
         73 . The method of    claim 72   , further comprising the steps of: 
 forming a first radio frequency power supply for providing radio frequency power to said first set of inductively-coupled coil segments; and    forming at least one separate radio frequency power supply for providing radio frequency power to said at least one separate set of inductively-coupled coil segments;    said first radio frequency power supply and said at least one separate radio frequency power supply formed to achieve uniform plasma density and ion current density in a semiconductor device plasma fabrication equipment process environment acting on at least one substrate.    
     
     
         74 . The method of    claim 74   , further comprising the step of utilizing said first radio frequency power supply and said at least one separate radio frequency power supply to operate independently for providing process control flexibility and uniformity adjustment during a plasma fabrication process.  
     
     
         75 . The method of    claim 73   , further comprising the steps of: 
 utilizing a first radio frequency power supply for providing radio frequency power to said first set of inductively-coupled coil segments; and    utilizing at least one separate radio frequency power supply for providing RF power to said at least one separate set of inductively-coupled coil segments;    said first radio frequency power supply and said at least one separate radio frequency power supply being operated to achieve sufficiently intense plasma density and ion current density in a plasma fabrication process environment.    
     
     
         76 . The method of    claim 73   , further comprising the step of forming said at least one separate set of inductively-coupled coil segments to comprise a plurality of inductively-coupled coil broken rings sized according to a predetermined substrate size.  
     
     
         77 . The method of    claim 73   , further comprising the step of interconnecting said inductively-coupled coil segments using at least one series capacitor to minimize electric field induced arcing in a plasma fabrication process environment.  
     
     
         78 . The method of    claim 73   , further comprising the step of utilizing at least one in situ sensor for association within the plasma fabrication process environment to enable multi-zone control of said first set of inductively-coupled coil segments and said at least one separate set of inductively-coupled coil segments.