Method and device for measuring wafer potential or temperature
The present invention attracts a wafer 6 , placed on a susceptor 5 , toward the susceptor 5 by the electrostatic attractive power of an electrostatic chuck electrode 7 , varies the output voltage of a variable direct current power source 23 for the electrostatic chuck electrode 7 while measuring the temperature of the wafer 6 by a temperature detection sensor 21 ; and detects the potential of the wafer 6 based on the output voltage of the variable direct current power source 23 at a time when the temperature of the wafer 6 peaks.
1. A wafer potential measuring method, comprising:
attracting a wafer, placed on a base stand, toward said base stand by an electrostatic attractive power generated by application of an output voltage of a direct current power source;
varying the output voltage of said direct current power source while measuring a temperature of said wafer in an attracted state;
judging that the electrostatic attractive power to the wafer is zero when the temperature of the wafer peaks; and
detecting the output voltage of said direct current power source at a time when the electrostatic attractive power to the wafer is zero as a potential of said wafer.
2. A wafer potential measuring method, comprising:
attracting a wafer, placed on a base stand, toward said base stand by an electrostatic attractive power of an electrostatic chuck;
varying an output voltage of a direct current power source for said electrostatic chuck while measuring a temperature of said wafer in an attracted state;
judging that the electrostatic attractive power to the wafer is zero when the temperature of the wafer peaks; and
detecting the output voltage of said direct current power source at a time when the electrostatic attractive power to the wafer is zero as a potential of said wafer.
3. A wafer potential measuring method, comprising:
accelerating ions near a wafer, placed on a base stand, by application of an RF bias;
superimposing an output voltage of a direct current power source on said RF bias voltage in an ion-accelerated state;
attracting said wafer, placed on said base stand, toward said base stand by an electrostatic attractive power generated by application of the output voltage of said direct current power source;
varying the output voltage of said direct current power source while measuring a temperature of said wafer in an attracted state;
judging that the electrostatic attractive power to the wafer is zero when the temperature of the wafer peaks; and
detecting the output voltage of said direct current power source at a time when the electrostatic attractive power to said wafer is zero as a potential of said wafer.