Apparatus for Plasma Processing

Abstract

According to an embodiment, an apparatus for a plasma processing system is provided. The apparatus includes an interface, a radiating structure, and conductive offsets. The interface includes a first conductive plate couplable to an RF source, a second conductive plate disposed between the RF source and the first conductive plate, and conductive concentric ring structures disposed between the second conductive plate and a substrate holder. The conductive offsets are arranged to couple the conductive concentric ring structures to the radiating structure.

What is claimed is: 
     
         1 . An apparatus for a plasma processing system, the apparatus comprising:
 an interface comprising:
 a first conductive plate couplable to an RF source, 
 a second conductive plate disposed between the RF source and the first conductive plate, and 
 conductive concentric ring structures disposed between the second conductive plate and a substrate holder, 
   a radiating structure; and   conductive offsets arranged to couple the conductive concentric ring structures to the radiating structure.   
     
     
         2 . The apparatus of  claim 1 , wherein the second conductive plate is grounded. 
     
     
         3 . The apparatus of  claim 1 , wherein the radiating structure comprises a third conductive plate with a plurality of axisymmetric spiral cutouts. 
     
     
         4 . The apparatus of  claim 1 , wherein the plasma processing system comprises a processing chamber having a substrate holder, wherein a substrate to be processed in the processing chamber is mounted on the substrate holder. 
     
     
         5 . The apparatus of  claim 4 , wherein the apparatus is disposed external to the processing chamber. 
     
     
         6 . The apparatus of  claim 1 , wherein the first conductive plate is coupled to the RF source via a coaxial conductive structure, and wherein the RF source feeds RF power to first conductive plate via the coaxial conductive structure. 
     
     
         7 . The apparatus of  claim 1 , further comprising non-conductive offsets, the radiating structure coupled to an insulating structure disposed between a conductive inner ring structure of the conductive concentric ring structures and a conductive outer ring structure of the conductive concentric ring structures by the non-conductive offsets. 
     
     
         8 . The apparatus of  claim 1 , wherein the interface, the radiating structure, and the conductive offsets form a resonant circuit in response to the RF source providing an RF power to the first conductive plate. 
     
     
         9 . An apparatus for a plasma processing system, the apparatus comprising:
 an interface comprising:
 a first conductive structure couplable to an RF source, 
 a second conductive structure disposed between the RF source and the first conductive structure, each concentric conductive structure isolated from the second conductive structure by an air gap, and 
 concentric conductive structures; and 
   a radiating structure coupled to the interface.   
     
     
         10 . The apparatus of  claim 9 , wherein each concentric conductive structure is isolated from an adjacent concentric conductive structure by the air gap. 
     
     
         11 . The apparatus of  claim 9 , further comprising conductive offsets coupling the concentric conductive structures to the radiating structure. 
     
     
         12 . The apparatus of  claim 9 , wherein a resonant frequency of the radiating structure is between 5 and 100 megahertz (MHz). 
     
     
         13 . The apparatus of  claim 9 , wherein the radiating structure comprises:
 a conductive plate having spiral cutouts; and   an inner circular cutout, wherein the first conductive structure is arranged substantially on a same plane as the radiating structure and positioned inside the inner circulator cutout.   
     
     
         14 . The apparatus of  claim 9 , wherein the plasma processing system comprises a processing chamber having a substrate holder, wherein a substrate to be processed in the processing chamber is mounted on the substrate holder. 
     
     
         15 . An antenna system for exciting plasma by inductive coupling, the antenna system comprising:
 a plate;   a conductive ring structure arranged in parallel to the plate, the plate and the conductive ring structure forming a first capacitor, the capacitance value of the first capacitor being substantially the same along one conductive ring structure;   conductive offsets, each conductive offset having a first end and a second end, a first end of each conductive offset coupled to the conductive ring structure in a perpendicular arrangement, each conductive offset arranged equal distance from other conductive offsets along the conductive ring structure; and   a plurality of spiral arms coupled to a corresponding second end of each conductive offset, each spiral arm arranged in a radial, azimuthal, and nested arrangement, each spiral arm having the same shape, length, and spacing, the plurality of spiral arms, conductive offsets, and the conductive ring structure forming a resonant structure that resonates at an RF frequency.   
     
     
         16 . The antenna system of  claim 15 , further comprising at least one drive conductive structure capacitively coupled to the resonant structure and couplable to an RF source. 
     
     
         17 . The antenna system of  claim 15 , further comprising a conductive coil structure inductively coupled to the resonant structure, the conductive coil structure and the resonant structure forming an inductively coupled pair, and the conductive coil structure being couplable to an RF source. 
     
     
         18 . The antenna system of  claim 15 , wherein the conductive ring structure comprises a conductive inner ring structure and a conductive outer ring structure adjacent to the conductive inner ring structure, each of the conductive inner ring structure and the conductive outer ring structure being coupled to the plurality of spiral arms by the conductive offsets. 
     
     
         19 . The antenna system of  claim 15 , wherein one of an inner or an outer edge of each of the plurality of spiral arms is connected to the conductive ring structure by the conductive offsets, and wherein another edge of the each of the plurality of spiral arms not directly connected to a conductive structure or ground. 
     
     
         20 . The antenna system of  claim 15 , wherein the plurality of spiral arms, the plate, and the conductive ring structure are arranged substantially parallel to each other.