Analysis method and semiconductor etching apparatus

Abstract

There is provided a method of analyzing data obtained from an etching apparatus for micromachining a wafer using plasma. This method includes the following steps: acquiring the plasma light-emission data indicating light-emission intensities at a plurality of different wavelengths and times, the plasma light-emission data being measured under a plurality of different etching processing conditions, and being obtained at the time of the etching processing, evaluating the relationship between changes in the etching processing conditions and changes in the light-emission intensities at the plurality of different wavelengths and times with respect to the wavelengths and times of the plasma light-emission data, and identifying the wavelength and the time of the plasma light-emission data based on the evaluation result, the wavelength and the time being to be used for the adjustment of the etching processing condition.

1 . An analysis method of identifying a wavelength and a time of plasma light-emission data, said wavelength and said time of said plasma light-emission data being to be used for the adjustment of an etching processing condition in a semiconductor etching processing for applying said etching processing to a semiconductor wafer using said plasma, said analysis method, comprising:
 an acquisition step of acquiring said plasma light-emission data indicating light-emission intensities at a plurality of different wavelengths and times, said plasma light-emission data being measured under a plurality of different etching processing conditions, and being obtained at the time of said etching processing;   a first evaluation step of evaluating the relationship between changes in said etching processing conditions and changes in said light-emission intensities at said plurality of different wavelengths and times with respect to said wavelengths and times of said plasma light-emission data; and   an identification step of identifying said wavelength and said time of said plasma light-emission data based on the result of said first evaluation step, said wavelength and said time of said plasma light-emission data being to be used for said adjustment of said etching processing condition.   
     
     
         2 . The analysis method according to  claim 1 , wherein,
 at said first evaluation step, said relationship between said changes in said etching processing conditions and said changes in said light-emission intensities at said plurality of different wavelengths and times with respect to said wavelengths and times of said plasma light-emission data is evaluated using a prediction error or a correlation coefficient.   
     
     
         3 . The analysis method according to  claim 1 , further comprising:
 a second evaluation step of evaluating the relationship between said light-emission intensities at said plurality of different wavelengths and times of said plasma light-emission data, and the etching processing result, and wherein,   at said identification step, said wavelength and said time of said plasma light-emission data are identified from said result of said first evaluation step and the result of said second evaluation step, said wavelength and said time of said plasma light-emission data being to be used for said adjustment of said etching processing condition.   
     
     
         4 . The analysis method according to  claim 3 , wherein,
 at said second evaluation step, said relationship between said light-emission intensities at said plurality of different wavelengths and times of said plasma light-emission data, and said etching processing result is evaluated using a prediction error or a correlation coefficient.   
     
     
         5 . The analysis method according to  claim 4 , wherein,
 at said identification step, said wavelength and said time of said plasma light-emission data are identified so that a function becomes equal to its minimum value, said prediction error or said correlation coefficient at said first evaluation step and said prediction error or said correlation coefficient at said second evaluation step being used in said function.   
     
     
         6 . The analysis method according to  claim 4 , wherein
 said wavelength and said time of said plasma light-emission data are identified so that the sum total of said prediction error at said first evaluation step and a product becomes equal to its minimum value, said product being obtained by multiplying said prediction error at said second evaluation step by a coefficient, said coefficient indicating said relationship between said light-emission intensities at said plurality of different wavelengths and times of said plasma light-emission data, and said etching processing result.   
     
     
         7 . An analysis method of calculating an adjustment value of said etching processing condition so that said adjustment value becomes equal to a target value of said etching processing result, said adjustment value being calculated using said relationship between said light-emission intensity of said plasma light-emission data at said wavelength and said time, and said etching processing result, said wavelength and said time being identified using said analysis method according to  claim 1 .