Plasma Etching Apparatus

Abstract

A plasma etching apparatus includes a vacuum processing chamber for performing plasma processing on a workpiece, a gas introducer, a high frequency power feeder, a spectroscope, and an arithmetic unit for determining an endpoint of etching of the workpiece. The arithmetic unit includes a regression line computing unit for computing a regression line on the basis of time-sequential data of luminous intensity of a specific wavelength sampled by the spectroscope, a distance computing unit for computing a distance from the time-sequential data to the regression line, a computing unit for calculating a distance in a time-base direction by computing a slope of the regression line, and the distance from the time-sequential data to the regression line, computed by the distance computing unit, and an endpoint determiner for outputting an endpoint determination signal on the basis of the distance in the time-base direction computed by the computing unit.

1 . A plasma etching apparatus comprising:
 a vacuum processing chamber for performing plasma processing on a workpiece;   a gas introduction means for introducing an etching gas to the vacuum processing chamber;   a high frequency feeding means for feeding high-frequency power for producing plasma in the vacuum processing chamber;   a spectroscope for measuring a spectrum of light of a specific wavelength emitted by the plasma; and   an arithmetic unit for determining an endpoint of etching of the workpiece,   wherein the arithmetic unit is provided with:
 a regression line computing unit for computing a regression line on the basis of time-sequential data of luminous intensity of the specific wavelength sampled by the spectroscope; 
 a distance computing unit for computing a distance from the time-sequential data to the regression line; 
 a computing unit for calculating a distance in a time-base direction by computing a slope of the regression line, and the distance from the time-sequential data to the regression line, computed by the distance computing unit; and 
 an endpoint determiner for outputting an endpoint determination signal on the basis of the distance in the time-base direction computed by the computing unit. 
   
     
     
         2 . A plasma etching apparatus comprising:
 a vacuum processing chamber for performing plasma processing on a workpiece;   a gas introduction means for introducing an etching gas to the vacuum processing chamber;   a high frequency feeding means for feeding high-frequency power for producing plasma in the vacuum processing chamber;   a spectroscope for measuring a spectrum of light of a specific wavelength emitted by the plasma; and   an arithmetic unit for determining an endpoint of etching of the workpiece,   wherein the arithmetic unit is provided with:
 a regression line computing unit for computing a regression line on the basis of time-sequential data of luminous intensity of the specific wavelength sampled by the spectroscope; 
 a distance computing unit for computing a distance from the time-sequential data to the regression line; 
 a computing unit for calculating a distance in a time-base direction by computing a slope of the regression line, and the distance from the time-sequential data to the regression line, computed by the distance computing unit; and 
 an endpoint determiner for outputting an endpoint determination signal on the basis of the product of the maximum value in the distance in the time-base direction computed by the computing unit by the slop of the regression line. 
   
     
     
         3 . A plasma etching apparatus comprising:
 a vacuum processing chamber performing plasma processing on a workpiece;   a gas introduction means for introducing an etching gas to the vacuum processing chamber;   a high frequency feeding means for feeding high-frequency power for producing plasma in the vacuum processing chamber;   a spectroscope for measuring a spectrum of light of a specific wavelength emitted by the plasma; and   an arithmetic unit for determining an endpoint of etching of the workpiece,   wherein the arithmetic unit is provided with:
 a regression line computing unit for computing a regression line on the basis of time-sequential data of luminous intensity of the specific wavelength sampled by the spectroscope; and 
 an endpoint determiner for outputting an endpoint determination signal on the basis of the product of the maximum value of an area, which is surrounded by the regression line and the time-sequential data, by a difference between an area formed above the regression line and an area formed below the regression line.