Inductively Coupled Plasma Source for Plasma Processing

Abstract

Plasma processing apparatus and methods are disclosed. Embodiments of the present disclosure include a processing chamber having an interior space operable to receive a process gas, a substrate holder in the interior of the processing chamber operable to hold a substrate, and at least one dielectric window. A metal shield is disposed adjacent the dielectric window. The metal shield can have a peripheral portion and a central portion. The processing apparatus includes a primary inductive element disposed external to the processing chamber adjacent the peripheral portion of the metal shield. The processing apparatus can further include a secondary inductive element disposed between the central portion of the metal shield and the dielectric window. The primary and secondary inductive elements can perform different functions, can have different structural configurations, and can be operated at different frequencies.

1 - 20 . (canceled) 
     
     
         21 . A plasma processing apparatus, comprising:
 a processing chamber having an interior space operable to receive a process gas;   a substrate holder in the interior of the processing chamber operable to hold a substrate;   at least one dielectric window; and   a first inductive element disposed external to the processing chamber and adjacent the dielectric window, the first inductive element comprising a coil and a magnetic flux concentrator of ferrite material;   a second inductive element disposed over a peripheral portion of the processing chamber, the second inductive element comprising a multi-turn coil; and   a grounded metal shield separating the first inductive element and the second inductive element.   
     
     
         22 . The plasma processing apparatus of  claim 21 , wherein the magnetic flux concentrator has a truncated shape. 
     
     
         23 . The plasma processing apparatus of  claim 21 , wherein the magnetic flux concentrator has an L-shape. 
     
     
         24 . The plasma processing apparatus of  claim 21 , wherein the dielectric window has a relatively flat central portion and an angled peripheral side portion. 
     
     
         25 . The plasma processing apparatus of  claim 24 , wherein the second inductive element is adjacent the angled peripheral side portion of the dielectric window and the first inductive element is adjacent the relatively flat central portion of the dielectric window. 
     
     
         26 . The plasma processing apparatus of  claim 21 , wherein the apparatus further includes a Faraday shield located between the second inductive element and the dielectric window. 
     
     
         27 . The plasma processing apparatus of  claim 26 , wherein the Faraday shield is grounded. 
     
     
         28 . The plasma processing apparatus of  claim 26 , wherein the metal shield and the Faraday shield form a unitary body. 
     
     
         29 . The plasma processing apparatus of  claim 26 , wherein the Faraday shield comprises a slotted metal shield that reduces capacitive coupling between the second inductive element and a plasma formed in the process chamber interior. 
     
     
         30 . The plasma processing apparatus of  claim 21 , wherein the metal shield is disposed around the first inductive element. 
     
     
         31 . The plasma processing apparatus of  claim 21 , wherein the dielectric window includes a space in a central portion of the dielectric window for a showerhead to feed process gas into the interior space. 
     
     
         32 . The plasma processing apparatus of  claim 21 , further comprising a first RF generator configured to provide electromagnetic energy at a first frequency to the first inductive element and a second RF generator configured to provide electromagnetic energy at a second frequency to the second inductive element. 
     
     
         33 . The plasma processing apparatus of  claim 32 , wherein the first frequency is different from the second frequency. 
     
     
         34 . The plasma processing apparatus of  claim 33 , wherein the first frequency is in the range of about 1.75 MHz to about 2.15 MHz and the second frequency is about 13.56 MHz. 
     
     
         35 . A plasma processing apparatus, comprising:
 a processing chamber having an interior space operable to receive a process gas;   a substrate holder in the interior of the processing chamber operable to hold a substrate;   at least one dielectric window, the dielectric window having a relatively flat central portion and an angled peripheral side portion; and   a first inductive element disposed external to the processing chamber and adjacent the relatively flat central portion of the dielectric window, the first inductive element comprising a coil and a magnetic flux concentrator of ferrite material;   a second inductive element disposed over a peripheral portion of the processing chamber adjacent the angled peripheral side portion of the dielectric window, the second inductive element comprising a multi-turn coil; and   a grounded metal shield separating the first inductive element and the second inductive element;   a Faraday shield located between the second inductive element and the dielectric window, the Faraday shield and the metal shield forming a unitary body.   
     
     
         36 . The plasma processing apparatus of  claim 35 , wherein the magnetic flux concentrator has a truncated shape. 
     
     
         37 . The plasma processing apparatus of  claim 35 , wherein the magnetic flux concentrator has an L-shape. 
     
     
         38 . The plasma processing apparatus of  claim 35 , wherein the Faraday shield comprises a slotted metal shield that reduces capacitive coupling between the second inductive element and a plasma formed in the process chamber interior. 
     
     
         39 . The plasma processing apparatus of  claim 35 , further comprising a first RF generator configured to provide electromagnetic energy at a first frequency to the first inductive element and a second RF generator configured to provide electromagnetic energy at a second frequency to the second inductive element, wherein the first frequency is different from the second frequency. 
     
     
         40 . The plasma processing apparatus of  claim 39 , wherein the first frequency is in the range of about 1.75 MHz to about 2.15 MHz and the second frequency is about 13.56 MHz.