Semiconductor processing system and methods using capacitively coupled plasma

Abstract

Substrate processing systems are described that have a capacitively coupled plasma (CCP) unit positioned inside a process chamber. The CCP unit may include a plasma excitation region formed between a first electrode and a second electrode. The first electrode may include a first plurality of openings to permit a first gas to enter the plasma excitation region, and the second electrode may include a second plurality of openings to permit an activated gas to exit the plasma excitation region. The system may further include a gas inlet for supplying the first gas to the first electrode of the CCP unit, and a pedestal that is operable to support a substrate. The pedestal is positioned below a gas reaction region into which the activated gas travels from the CCP unit.

1 . A substrate processing system comprising:
 a capacitively coupled plasma (CCP) unit positioned inside a process chamber, wherein the CCP unit comprises a plasma excitation region formed between a first electrode and a second electrode, and wherein the first electrode comprises a first plurality of openings to permit a first gas to enter the plasma excitation region, and the second electrode comprises a second plurality of openings to permit an activated gas to exit the plasma excitation region;   a gas inlet for supplying the first gas to the first electrode of the CCP unit; and   a pedestal that is operable to support a substrate, wherein the pedestal is positioned below a gas reaction region into which the activated gas travels from the CCP unit.   
     
     
         2 . The system of  claim 1 , wherein the system further comprises a showerhead positioned between the second electrode of the CCP unit and the gas reaction region above the pedestal, wherein the showerhead comprises a first plurality of showerhead channels that permit passage of the activated gas to the gas reaction region, and a second plurality of channels that permit passage of a second gas to the gas reaction region. 
     
     
         3 . The system of  claim 2 , wherein the second plurality of openings in the second electrode are concentrically aligned with the first plurality of showerhead channels. 
     
     
         4 . The system of  claim 1 , wherein the system further comprises one or more second gas inlets positioned between the second electrode and the pedestal, wherein the second gas inlets supply a second gas to the gas reaction region. 
     
     
         5 . The system of  claim 1 , wherein the system further comprises a remote plasma system coupled to the gas inlet and operable to excite the first gas entering the process chamber through the gas inlet. 
     
     
         6 . The system of  claim 1 , wherein the activated gas comprises at least one reactive radical. 
     
     
         7 . A substrate processing system comprising:
 a gas inlet for supplying a first gas to a processing chamber;   an electrode comprising a plurality of openings;   a showerhead comprising a first plurality of channels that permit the passage of an activated gas to a gas reaction region in the processing chamber, and a second plurality of channels that permit passage of a second gas to the gas reaction region, wherein the activated gas is formed in a plasma excitation region between the electrode and the showerhead, which also acts as a second electrode; and   a pedestal that is operable to support a substrate, wherein the pedestal is positioned below the gas reaction region.   
     
     
         8 . The system of  claim 7 , wherein the first plurality of channels in the showerhead suppresses plasma in the plasma excitation region from entering the gas reaction region, while permitting the activated gas to pass through the showerhead. 
     
     
         9 . The system of  claim 7 , wherein the system further comprises a one or more second gas inlets positioned between the showerhead and the pedestal, wherein the second gas inlets supply a second gas to the gas reaction region. 
     
     
         10 . The system of  claim 7 , wherein the system further comprises a remote plasma system coupled to the gas inlet and operable to excite the first gas entering the process chamber through the gas inlet. 
     
     
         11 . A substrate processing system comprising:
 a gas inlet for supplying a first gas to a processing chamber;   an electrode comprising a first plurality of openings;   an ion suppressor comprising an electrically conductive plate having a second plurality of openings that permit the passage of an activated gas to a gas reaction region in the processing chamber, wherein the activated gas is formed in a plasma excitation region between the electrode and the ion suppressor; and   a pedestal that is operable to support a substrate, wherein the pedestal is positioned below the gas reaction region.   
     
     
         12 . The system of  claim 11 , wherein the system further comprises a showerhead positioned between the ion suppressor and the pedestal. 
     
     
         13 . The system of  claim 11 , wherein the system further comprises a remote plasma system coupled to the gas inlet and operable to excite the first gas entering the process chamber through the gas inlet. 
     
     
         14 . The system of  claim 11 , wherein the system comprises an electrical power supply coupled to the electrode and the ion suppressor, wherein the power supply is operable to create an adjustable bias voltage in the ion suppressor to adjust an ion concentration in the activated gas passing from the plasma excitation region to the gas reaction region