Plasma processing apparatus

Abstract

A plasma processing apparatus includes a vacuum chamber, a sample table that places the sample in the vacuum chamber, and a gas supply unit faced to the sample table and having a gas supply surface with a diameter larger than that of the sample, wherein gas injection holes each having identical diameter are provided concentrically on the gas supply surface, a hole number density of the gas injection holes present in an outer diameter position of the sample or in an outside of the outer diameter position is made higher than that of the gas injection holes present inside the outer diameter position of the sample, and a diameter of the gas injection holes present in the outer diameter position of the sample or in the outside from the outer diameter position is larger than that of the gas injection holes present inside the diameter of the sample.

1 . A plasma processing apparatus for applying a surface processing to a sample, comprising:
 a vacuum chamber;   a sample table that places the sample in the vacuum chamber, and   a gas supply unit faced to the sample table and having a gas supply surface with a diameter larger than that of the sample, wherein   gas injection holes each having identical diameter are provided concentrically on the gas supply surface of the gas supply unit, and   a hole number density of the gas injection holes present in an outer diameter position of the sample or in an outside of the outer diameter position is made higher than that of the gas injection holes present inside the outer diameter position of the sample.   
     
     
         2 . The apparatus according to  claim 1  wherein the hole number density of the gas injection holes present in an outer diameter position of the sample or in an outside of the outer diameter position is present in a range from 1.5 to 4.0 times that of the gas injection holes present inside the outer diameter position of the sample. 
     
     
         3 . The apparatus according to  claim 1  wherein the gas injection holes present in the outer diameter position of the sample or in the outside of the outer diameter position are present in a range of 1.0 to 1.1 times the diameter of the sample. 
     
     
         4 . The apparatus according to  claim 1  wherein an aspect ratio (D/L) is equal to or greater than 2, where the diameter of sample is D, and a distance from the sample to the gas supply surface is L. 
     
     
         5 . A plasma processing apparatus for applying a surface processing to a sample, comprising:
 a vacuum chamber;   a sample table that places the sample in the vacuum chamber; and   a gas supply unit faced to the sample table and having a gas supply surface with a diameter larger than that of the sample, wherein   gas injection holes are provided concentrically on the gas supply surface of the gas supply unit, and   a diameter of the gas injection holes present in an outer diameter position of the sample or in an outside from the outer diameter position is larger than that of the gas injection holes present inside from the outer diameter position of the sample.   
     
     
         6 . The apparatus according to  claim 5  wherein a diameter of the gas injection holes present in the outer diameter position of the sample or in an outside of the outer diameter position is present in a range of 1.1 to 1.5 times that of the gas injection holes present inside the outer diameter position of the sample. 
     
     
         7 . The apparatus according to  claim 5  wherein the gas injection holes present in the outer diameter position of the sample or in the outside of the outer diameter position are present in a range of 1.0 to 1.1 times the diameter of the sample. 
     
     
         8 . The apparatus according to  claim 5  wherein an aspect ratio (D/L) is equal to or greater than 2, where the diameter of sample is D, and a distance from the sample to the gas supply surface is L.