Plasma processing method and plasma processing apparatus

A plasma processing method for processing a sample located on a sample stage disposed inside a processing room arranged in a vacuum chamber using a plasma,

• wherein the sample stage comprises:
• a film which is composed of an insulative material, the film constituting a surface on which said sample is located;
• a disk-shaped member which is made of a heat conductive material, wherein a lower portion of the film is disposed on an upper surface of the disk-shaped member;
• a plurality of heaters disposed inside said film which are arranged in a first region which is ring-shaped and disposed in an outer peripheral side of said film and in a second region which is disposed in a central side of the first region next thereto;
• a plurality of coolant channels which are arranged in said disk-shaped member and in which a coolant for cooling said disk-shaped member flows;
• a plurality of temperature sensors which are respectively disposed at a lower portion of each of the first and second regions between said upper surface of said disk-shaped member and said coolant channels, the plurality of temperature sensors configured to detect temperatures of lower portions of said disk-shaped member corresponding to the respective first and second regions;
• and
• a plurality of power sources each of which outputs and adjusts an electric power to each of the heaters disposed in the first and second regions, and
• the processing method comprising steps of:
• (i) positioning the sample onto the upper surface of the sample stage;
• (ii) generating a plasma inside the processing room;
• and
• (iii) adjusting at least one output from one of said power sources by using a result obtained by estimating a temperature of the upper surface of the disk-shaped member while processing the sample, wherein step (iii) includes substeps of:
• (a) obtaining an addition value Y1 of a value obtained by multiplying a sum of outputs from the plurality of temperature sensors by a first predetermined coefficient and a value obtained by multiplying a sum of outputs of the plurality of power sources by a second predetermined coefficient;
• (b) obtaining an addition value Y2 of a value obtained by multiplying a difference between outputs from the plurality of temperature sensors by a third predetermined coefficient and a value obtained by multiplying a difference between outputs of the plurality of power sources by a fourth predetermined coefficient;
• and
• (c) adjusting a supply of the output from the power source for the heater corresponding to the first region based upon a difference between a set temperature of the portion in the first region of the disk-shaped member and the presumed present value of the temperature of the first region which is obtained from a difference value between Y1 and Y2;
• and
• (d) adjusting a supply of the output from the power source for the heater corresponding to the second region based upon a difference between the set temperature of the portion in the second region of the disk-shaped member and the presumed present value of the temperature of the second region which is obtained from an addition value of the Y1 and Y2.