Method and apparatus for plasma processing

Abstract

Plasma processing focus ring design arrangements, including: acquiring a surface voltage and a sheath thickness above a surface of the object to be processed, and a surface voltage and a sheath thickness above a surface of the focus ring, by an equivalent circuit analysis; performing 2D plasma and 2D electric field analysis, based on the equivalent circuit analysis; and designing configuration of the focus ring and the processing stage, to achieve a plasma-sheath interface flattening condition by making a sum of a height from a height reference point to a surface of the object and a sheath thickness from the surface of the object to a plasma-sheath interface above the object, equal to a sum of a height from the height reference point to a surface of the focus ring and a sheath thickness from the surface of the focus ring to a plasma-sheath interface above the focus ring.

What is claimed is: 
     
         1 . A focus ring designed using a design method for designing a configuration of the focus ring and a processing stage for placing an object to be processed applied to a plasma processing apparatus for plasma processing the object to be processed, the plasma processing apparatus including the processing stage, the focus ring, and a RF power supply for applying RF bias to the object to be processed and to the focus ring, with the focus ring being disposed on the processing stage and surrounding the object to be processed, the design method comprising:
 acquiring a voltage on a surface of the object to be processed and a sheath thickness above a surface of the object to be processed, and a voltage on a surface of the focus ring and a sheath thickness above a surface of the focus ring, by an equivalent circuit analysis; performing a two dimensional plasma analysis and a two dimensional electric field analysis, based on a result of the equivalent circuit analysis; and   designing the configuration of the focus ring and the processing stage, based on results of the two dimensional plasma analysis and the two dimensional electric field analysis, to achieve a plasma-sheath interface flattening condition making a first voltage drop of an RF voltage from the processing stage to a plasma-sheath interface above the object to be processed equal to a second voltage drop of an RF voltage from the processing stage to a plasma-sheath interface above the focus ring, by making a sum of a height from a height reference point to a surface of the object to be processed and a sheath thickness from the surface of the object to be processed to a plasma-sheath interface above the object to be processed, equal to a sum of a height from the height reference point to a surface of the focus ring and a sheath thickness from the surface of the focus ring to a plasma-sheath interface above the focus ring, wherein the first voltage drop is calculated on the basis of a voltage on a surface of the object to be processed and the plasma-sheath interface above the object to be processed, and   wherein the second voltage drop is calculated on the basis of a voltage on a surface of the focus ring and the plasma-sheath interface above the focus ring.   
     
     
         2 . A focus ring designed using a method of designing a design for the focus ring applied to a plasma processing apparatus for plasma processing the object to be processed, the plasma processing apparatus including the processing stage for placing the object to be processed, the focus ring, and a RF power supply for applying RF bias to the object to be processed and to the focus ring, with the focus ring being disposed on the processing stage and surrounding the object to be processed, the method comprising:
 acquiring a voltage on a surface of the object to be processed and a sheath thickness above a surface of the object to be processed, and a voltage on a surface of the focus ring and a sheath thickness above a surface of the focus ring, by an equivalent circuit analysis; performing a two dimensional plasma analysis and a two dimensional electric field analysis, based on a result of the equivalent circuit analysis; and   designing the configuration of the focus ring and the processing stage, based on results of the two dimensional plasma analysis and the two dimensional electric field analysis, to achieve a plasma-sheath interface flattening condition making a first voltage drop of an RF voltage from the processing stage to a plasma-sheath interface above the object to be processed equal to a second voltage drop of an RF voltage from the processing stage to a plasma-sheath interface above the focus ring, by making a sum of a height from a height reference point to a surface of the object to be processed and a sheath thickness from the surface of the object to be processed to a plasma-sheath interface above the object to be processed, equal to a sum of a height from the height reference point to a surface of the focus ring and a sheath thickness from the surface of the focus ring to a plasma-sheath interface above the focus ring, wherein the first voltage drop is calculated on the basis of a voltage on a surface of the object to be processed and the plasma-sheath interface above the object to be processed, and   wherein the second voltage drop is calculated on the basis of a voltage on a surface of the focus ring and the plasma-sheath interface above the focus ring.