Method of setting etching parameters and system therefor

Abstract

The present invention relates to a system that automatically calculates optimal etching parameters in order to perform desired etching in an etching process in semiconductor manufacturing. A model representing etching parameters and an etching performance quantitative value at the time when etching is performed with the etching parameters is prepared in advance, and when desired etching is performed, optimal etching parameters are calculated from the model.

1 . A system for setting parameters for etching, comprising: 
 an electron beam image acquiring unit that acquires an electron beam image of a pattern formed on a surface of a wafer treated by an etching apparatus;    a unit that processes the electron beam image of the pattern formed on the surface of the wafer, which is obtained by the electron beam image acquiring unit, and judges workmanship of the pattern;    a unit that presents a result of judgment by the workmanship judging unit to a user;    a unit that calculates corrected values of etching parameters for the etching apparatus on the basis of the result of judgment by the workmanship judging unit; and    a transmitting unit that transmits the corrected values calculated by the calculating unit to the etching apparatus.    
   
   
       2 . A system for setting parameters for etching according to  claim 1 , wherein the electron beam image acquiring unit includes: an electron beam irradiating unit that irradiates a converged electron beam on the surface of the wafer and scans the surface; and a detecting unit that detects secondary charged particles that are generated from the surface of the wafer as the electron beam irradiating unit irradiates an electron beam on the surface and scans the surface, and the electron beam irradiating unit can change an incident angle of the converged electron beam with respect to the pattern on the surface of the wafer in a range from 0° to 15° with respect to a normal direction of the surface of the wafer.  
   
   
       3 . A system for setting parameters for etching according to  claim 1 , wherein the unit that judges workmanship of the pattern includes: a dimension extracting unit that processes the image of the pattern to calculate dimensions of plural portions of the pattern as workmanship of the pattern; and a comparing unit that compares the dimensions of the plural portions of the pattern calculated in the dimension extracting unit with target values set in advance.  
   
   
       4 . A system for setting parameters for etching according to  claim 1 , wherein the unit that calculates corrected values of etching parameters for the etching apparatus includes; a storing unit that stores a model representing a relation between information on workmanship of a pattern and etching parameters; and a corrected value calculating unit that compares the information on workmanship of the pattern judged by the workmanship judging unit and the model stored in the storing unit to calculate corrected values of the etching parameters.  
   
   
       5 . A system for setting parameters for etching according to  claim 1 , wherein, in the case in which the pattern is a contact hole, the unit that judges workmanship of a pattern processes an image of the pattern to calculate any one of a hole diameter, hole roundness, a white band portion width, roughness of a white band portion contour, roughness of a hole bottom pattern, a hole depth, and an inclination angle of a hole wall portion as a characteristic amount of the pattern, and judges workmanship of the pattern on the basis of the calculated characteristic amount.  
   
   
       6 . A system for setting parameters for etching according to  claim 1 , wherein, in the case in which the pattern is a line pattern, the unit that judges workmanship of a pattern calculates any one of a line width, a white band portion width in an image photographed by a scanning electron microscope, roughness of a white band portion contour, and an inclination angle of a wall portion as a characteristic amount of the pattern and judges workmanship of the pattern on the basis of the calculated characteristic amount.  
   
   
       7 . A system for setting parameters for etching, comprising: 
 an electron beam image acquiring unit that acquires an electron beam image of a pattern formed on a surface of a wafer treated by an etching apparatus;    a characteristic amount extracting unit that processing the electron beam image of the pattern formed on the surface of the wafer, which is obtained by the electron beam image acquiring unit, and extracts a characteristic amount of the pattern;    a unit that judges performance of acquiring information on a three-dimensional structure with the characteristic amount extracting unit;    a unit that presents a result of judgment by the performance judging unit to a user; and    a unit that calculates corrected values for etching parameters for the etching apparatus on the basis of a result of judgment by the performance judging unit.    
   
   
       8 . A system for setting parameters for etching according to  claim 7 , wherein the electron beam image acquiring unit includes: an electron beam irradiating unit that irradiates a converged electron beam on the surface of the wafer and scans the surface; and a detecting unit that detects secondary charged particles that are generated from the surface of the wafer as the electron beam irradiating unit irradiates an electron beam on the surface and scans the surface, the electron beam irradiating unit can change an incident angle of the converged electron beam with respect to the pattern on the surface of the wafer in a range from 0° to 15° with respect to a normal direction of the surface of the wafer.  
   
   
       9 . A system for setting parameters for etching according to  claim 7 , wherein, in the case in which the pattern is a contact hole, the characteristic amount extracting unit calculates any one of a hole diameter, hole roundness, a white band portion width, roughness of a white band portion contour, roughness of a hole bottom pattern, a hole depth, and an inclination angle of a hole wall portion as a characteristic amount of the pattern.  
   
   
       10 . A system for setting parameters for etching according to  claim 7 , wherein, in the case in which the pattern is a line pattern, the characteristic amount extracting unit calculates any one of a line width, a white band portion width in an image photographed by a scanning electron microscope, roughness of a white band portion contour, and an inclination angle of a wall portion as a characteristic amount of the pattern and judges workmanship of the pattern on the basis of the calculated characteristic amount.  
   
   
       11 . A system for setting parameters for etching according to  claim 7 , wherein the unit that calculates corrected values of etching parameters for the etching apparatus includes; a storing unit that stores a model representing a relation between information on workmanship of a pattern and etching parameters; and a corrected value calculating unit that compares the information on workmanship of the pattern judged by the performance judging unit and the model stored in the storing unit to calculate corrected values of the etching parameters.  
   
   
       12 . A system for setting parameters for etching according to  claim 7 , further,comprising a transmitting unit that transmits the corrected values calculated by the corrected value calculating unit to the etching apparatus.  
   
   
       13 . A method of setting parameters for etching, comprising the steps of: 
 acquiring an electron beam image of a pattern formed on a surface of a wafer treated by an etching apparatus;    processing the acquired electron beam image of the pattern formed on the surface of the wafer and judging workmanship of the pattern;    presenting a result of judging the workmanship to a user;    calculating corrected values of etching parameters for the etching apparatus on the basis of the result of judging the workmanship; and    transmitting the calculated corrected values to the etching apparatus.    
   
   
       14 . A method of setting parameters for etching according to  claim 13 , wherein, in the step of acquiring an electron beam image, a converged electron beam is irradiated on the surface of the wafer at an incident angle of a range between 0° to 15° with respect to a normal direction of the surface of the wafer to scan the surface of the wafer.  
   
   
       15 . A method of setting parameters for etching according to  claim 13 , wherein, in the step of judging workmanship of the pattern, in the case in which the pattern is a contact hole, an image of the pattern is processed, any one of a hole diameter, hole roundness, a white band portion width, roughness of a white band portion contour, roughness of a hole bottom pattern, a hole depth, and an inclination angle of a hole wall portion is calculated as a characteristic amount of the pattern, and workmanship of the pattern is judged on the basis of the calculated characteristic amount.  
   
   
       16 . A method of setting parameters for etching according to  claim 13 , wherein, in the step of judging workmanship of the pattern, in the case in which the pattern is a line pattern, any one of a line width, a white band portion width in an image photographed by a scanning electron microscope, roughness of a white band portion contour, and an inclination angle of a wall portion is calculated as a characteristic amount of the pattern and workmanship of the pattern is judged on the basis of the calculated characteristic amount.  
   
   
       17 . A method of setting parameters for etching, comprising the steps of: 
 acquiring an electron beam image of a pattern formed on a surface of a wafer treated by an etching apparatus;    processing the acquired electron image of the pattern formed on the surface of the wafer and extracting a characteristic amount of the pattern;    comparing the extracted characteristic amount of the pattern with data set in advance and judging workmanship of the pattern;    presenting a result of judging the workmanship to a user, and    calculating corrected values of etching parameters of the etching apparatus on the basis of the result of judging the workmanship.    
   
   
       18 . A method of setting parameters for etching according to  claim 17 , wherein, in the step of acquiring an electron beam image, a converged electron beam is irradiated on the surface of the wafer at an incident angle of a range between 0° to 15° with respect to a normal direction of the surface of the wafer to scan the surface of the wafer.  
   
   
       19 . A method of setting parameters for etching according to  claim 17 , wherein, in the step of extracting the characteristic amount, in the case in which the pattern is a contact hole, an image of the pattern is processed, and any one of a hole diameter, hole roundness, a white band portion width, roughness of a white band portion contour, roughness of a hole bottom pattern, a hole depth, and an inclination angle of a hole wall portion is calculated as a characteristic amount of the pattern.  
   
   
       20 . A method of setting parameters for etching according to  claim 17 , wherein, in the step of extracting the characteristic amount, in the case in which the pattern is a line pattern, any one of a line width, a white band portion width in an image photographed by a scanning electron microscope, roughness of a white band portion contour, and an inclination angle of a wall portion is calculated as a characteristic amount of the pattern and workmanship of the pattern is judged on the basis of the calculated characteristic amount.  
   
   
       21 . A method of setting parameters for etching according to  claim 17 , wherein, in the step of calculating corrected values of etching parameters for the etching apparatus, information on workmanship of the pattern judged in the step of judging workmanship is compared with a model representing a relation between information on workmanship of a pattern stored in advance and etching parameters, and corrected values of the etching parameters are calculated.  
   
   
       22 . A method of setting parameters for etching according to  claim 17 , further comprising the step of sending the calculated corrected values of the etching parameters to the etching apparatus.