Abstract:
A method of generating reference data is disclosed, in which two-value or multi-value gradated data of pixels is obtained in units of pixels from a design data of a pattern to be formed on an object, a processed data is obtained by carrying out calculations to the gradated data, and a reference data for use in a comparison with a sensed data obtained by image-picking up a pattern formed on the object is obtained based on the processed data, the method comprising carrying out a first calculation including a predetermined parameter to a value of an gradated data of a targeted pixel among the pixels to obtain a first processed data, and carrying out a second calculation including a predetermined parameter to the values of the gradated data of the targeted pixel and pixels located at the periphery of the targeted pixel to obtain a second processed data.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2004-000516, filed Jan. 5, 2004, the entire contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a reference data generating method for use in making a comparison with sensed data obtained by image-picking up a pattern formed on a photo mask, a semiconductor wafer or the like. 
   In addition, the present invention relates to a pattern defect checking apparatus and checking method for checking a pattern defect by comparing a sensed data obtained by image-picking up a pattern formed on a photo mask, a semiconductor wafer or the like with a reference data obtained by expanding a design data of the pattern. 
   Further, the present invention relates to a reference data generating program of generating a reference data for use in pattern defect check by a computer. 
   Also, the present invention relates to a method of manufacturing a semiconductor device by using a photo mask after checking a pattern defect by comparing a sensed data obtained by image-picking up a pattern formed on a photo mask with a reference data obtained by expanding a design data of the pattern. 
   2. Description of the Related Art 
   Conventionally, in the case of carrying out a defect check of a pattern formed on a photo mask for use in manufacturing semiconductor devices, light beams are radiated onto a photo mask from a light beam source such as a mercury lamp or a laser oscillation source. A pattern image data (sensed data) obtained by image-picking up light beams passed through the mask is compared with a reference data obtained by expanding a design data of the pattern, to detect an unmatched portion as a defect. In recent years, a photo mask pattern has been finer, and the size of a defect to be detected has been smaller than 100 nm. In addition, it is necessary to carry out a defect check with high sensitivity for a mask using a high resolution technique such as a phase shift or optical proximity effect correction. 
   In order to enhance detection sensitivity, it is necessary to enhance alignment between a reference data obtained by expanding a design data of a pattern to be formed on an object and a sensed data obtained by image-picking up a pattern formed on the object. In a conventional reference data generating method, a feature of a pattern targeted to be checked is geometrically calculated, and the calculated pattern feature is optically calculated (for example, Jpn. Pat. Appln. KOKAI Publication No. 2002-107309). 
   In such a conventional method, however, the calculation result largely depends on a calculation model, and figures smaller than an inspection pixel size may be arbitrarily calculated, and thus the alignment between the reference data and the sensed data is low. In particularly, in the optical proximity effect correction mask, dimensions of an assisting pattern are extremely small to a line width of a main pattern, thus making it difficult to obtain a reference data with high accuracy. In addition, a large amount of time has been required for calculation because geometrical and optical calculations are carried out. 
   As described above, in a pattern defect check for checking a pattern formed on an object targeted to be checked, it is necessary to provide a reference data from a pattern design data. However, a large amount of time is required to provide a reference data, and it is difficult to provide a reference data with high alignment with a sensed data. 
   BRIEF SUMMARY OF THE INVENTION 
   According to an aspect of the present invention, there is provided a method of generating reference data, in which two-value or multi-value gradated data of pixels arranged in a two-dimensional form is obtained in units of pixels from a design data of a pattern to be formed on an object, a processed data is obtained by carrying out calculations to the gradated data, and a reference data for use in a comparison with a sensed data obtained by image-picking up a pattern formed on the object is obtained based on the processed data, the method comprising: 
   carrying out a first calculation including a predetermined parameter to a value of an gradated data of a targeted pixel among the pixels to obtain a first processed data; and 
   carrying out a second calculation including a predetermined parameter to the values of the gradated data of the targeted pixel and pixels located at the periphery of the targeted pixel to obtain a second processed data. 
   According to another aspect of the present invention, there is provided a pattern defect detecting apparatus in which a sensed data is obtained by image-picking up a pattern formed on an object, two-value or multi-value gradated data of pixels arranged in a two-dimensional form is obtained in units of pixels from a design data of a pattern to be formed on the object, a processed data is obtained by carrying out calculations to the gradated data, and a reference data is obtained based on the processed data, and the reference data is compared with the sensed data, the apparatus comprising: 
   a first calculating circuit configured to carry out a calculation including a predetermined parameter to a value of an gradated data of a targeted pixel among the pixels to obtain a first processed data; and 
   a second calculating circuit configured to carry out a calculation including a predetermined parameter to the values of the gradated data of the targeted pixel and pixels located at the periphery of the targeted pixel to obtain a second processed data. 
   According to a further aspect of the present invention, there is provided a reference data generating program readable and executable by a computer, in which two-value or multi-value gradated data of pixels arranged in a two-dimensional form is obtained in units of pixels from a design data of a pattern to be formed on an object, a processed data is obtained by carrying out calculations to the gradated data, and a reference data for use in a comparison with a sensed data obtained by image-picking up a pattern formed on the object is obtained based on the processed data, the program comprising: 
   a first calculation to carry out a calculation including a predetermined parameter to a value of an gradated data of a targeted pixel among the pixels to obtain a first processed data; and 
   a second calculation to carry out a calculation including a predetermined parameter to the values of the gradated data of the targeted pixel and pixels located at the periphery of the targeted pixel to obtain a second processed data. 
   According to a further aspect of the present invention, there is provided a pattern defect detecting apparatus in which a sensed data obtained by image-picking up a pattern formed on an object is compared with a reference data obtained by developing a design data of a pattern to be formed on the object to detect a defect of the pattern formed on the object, comprising: 
   a gradated data generating circuit configured to generate two-value or multi-value gradated data of pixels in units of pixels from the design data; 
   a reference data generating circuit configured to generate a first processed data by multiplying a gradated value of a targeted pixel in the gradated data by a first coefficient in accordance with gradated values of pixels located at the periphery of the targeted pixel, a second processed data by rounding up a gradated value of the pixel in the first processed data by a first threshold value, a third processed data by rounding down a gradated value of the pixel in the second processed data by a second threshold value, a fourth processed data by multiplying a gradated value of the pixel in the third processed data by a second coefficient, and the reference data based on the fourth processed data; and 
   a pattern defect detecting circuit configured to compare the reference data with the sensed data. 
   According to a further aspect of the present invention, there is provided a method of detecting a pattern defect, in which a sensed data obtained by image-picking up a pattern formed on an object is compared with a reference data obtained by developing a design data of a pattern to be formed on the object to detect a defect of the pattern formed on the object, comprising: 
   generating two-value or multi-value gradated data of pixels in units of pixels from the design data, and generating a first processed data by multiplying a gradated value of a targeted pixel in the gradated data by a first coefficient in accordance with gradated values of pixels located at the periphery of the targeted pixel; 
   generating a second processed data by rounding up a gradated value of the pixel in the first processed data by a first threshold value; 
   generating a third processed data by rounding down a gradated value of the pixel in the second processed data by a second threshold value; 
   generating a fourth processed data by multiplying a gradated value of the pixel in the third processed data by a second coefficient; and 
   comparing the reference data obtained based on the fourth processed data with the sensed data. 
   According to a further aspect of the present invention, there is provided a reference data generating program readable and executable by a computer, in which a reference data for use in a comparison with a sensed data obtained by image-picking up a pattern is obtained by developing a design data of the pattern under control of a computer, comprising: generating two-value or multi-value gradated data of pixels in units of pixels from the design data; generating a first processed data by multiplying a gradated value of a targeted pixel in the gradated data by a first coefficient in accordance with a gradated value of a pixel located at the periphery of the targeted pixel; generating a second processed data by rounding up a gradated value of the pixel in the first processed data by a first threshold value; generating a third processed data by rounding down a gradated value of the pixel in the second processed data by a second threshold value; and generating a fourth processed data by multiplying a gradated value of the pixel in the third processed data by a second coefficient. 
   According to a further aspect of the present invention, there is provided a method of manufacturing a semiconductor device comprising:
         detecting a pattern defect of a photo mask having a semiconductor circuit pattern, by using the method of detecting a pattern defect, according to some embodiments as disclosed herein;   transferring the semiconductor circuit pattern on a semiconductor substrate, by using the photo mask after detecting the pattern defect; and   forming a semiconductor circuit having the semiconductor circuit pattern on the semiconductor substrate.       

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       FIG. 1  is a schematic diagram showing a construction of a pattern defect checking apparatus according to an embodiment of the present invention. 
       FIG. 2  is a flow chart adopted to illustrate a pattern defect checking method in the present embodiment. 
       FIG. 3  is a graph showing gradated data (graphic data) obtained from pattern design data. 
       FIG. 4  is a graph showing a profile of the graphic data, taken along the line  4 - 4  shown in  FIG. 3 . 
       FIG. 5  is a graph showing data (processing data) obtained by carrying out calculation in accordance with a first processing step to the graphic data shown in  FIG. 3 . 
       FIG. 6  is a graph showing a profile of the processing data shown in  FIG. 5 , taken along the line  6 - 6  shown in  FIG. 5 . 
       FIG. 7  is a graph showing data (processing data) obtained by carrying out calculation in accordance with a second processing step to the graphic data shown in  FIG. 5 . 
       FIG. 8  is a graph showing a profile of the processing data shown in  FIG. 7 , taken along the line  8 - 8  shown in  FIG. 7 . 
       FIG. 9  is a graph showing data (processing data) obtained by carrying out calculation in accordance with a third processing step to the graphic data shown in  FIG. 7 . 
       FIG. 10  is a graph showing a profile of the processing data shown in  FIG. 9 , taken along the line  10 - 10  shown in  FIG. 9 . 
       FIG. 11  is a graph showing data (processing data) obtained by carrying out calculation in accordance with a fourth processing step to the graphic data shown in  FIG. 9 . 
       FIG. 12  is a graph showing a profile of the processing data shown in  FIG. 11 , taken along the line  12 - 12  shown in  FIG. 11 . 
       FIG. 13  is a graph showing data (processing data) obtained by carrying out calculation in a fifth processing step to the graphic data shown in  FIG. 11 . 
       FIG. 14  is a graph showing a profile of the processing data shown in  FIG. 13 , taken along the line  14 - 14  shown in  FIG. 13 . 
       FIG. 15  is a graph showing data (processing data) obtained by carrying out calculation in accordance with a sixth processing step to the graphic data shown in  FIG. 13 . 
       FIG. 16  is a graph showing a profile of the processing data shown in  FIG. 15 , taken along the line  16 - 16  shown in  FIG. 15 . 
       FIG. 17  is a graph showing data (processing data) obtained by carrying out calculation in accordance with a seventh processing step to the graphic data shown in  FIG. 15 . 
       FIG. 18  is a graph showing a profile of the processing data shown in  FIG. 17 , taken along the line  18 - 18  shown in  FIG. 17 . 
       FIG. 19  is a cross sectional view showing a device structure in a step of a method of manufacturing a semiconductor device according to another embodiment of the present invention, which is used to explain the manufacturing method. 
       FIG. 20  is a cross sectional view showing a device structure in a step following to the step in  FIG. 19  of the method of manufacturing the semiconductor device according to the embodiment of the present invention, which is used to explain the manufacturing method of the semiconductor device. 
       FIG. 21  is a cross sectional view showing a device structure in a step following to the step in  FIG. 20  of the method of manufacturing the semiconductor device according to the embodiment of the present invention, which is used to explain the manufacturing method of the semiconductor device. 
       FIG. 22  is a cross sectional view showing a device structure in a step following to the step in  FIG. 21  of the method of manufacturing the semiconductor device according to the embodiment of the present invention, which is used to explain the manufacturing method of the semiconductor device. 
       FIG. 23  is a cross sectional view showing a device structure in a step following to the step in  FIG. 22  of the method of manufacturing the semiconductor device according to the embodiment of the present invention, which is used to explain the manufacturing method of the semiconductor device. 
       FIG. 24  is a cross sectional view showing a device structure in a step following to the step in  FIG. 23  of the method of manufacturing the semiconductor device according to the embodiment of the present invention, which is used to explain the manufacturing method of the semiconductor device. 
       FIG. 25  is a cross sectional view showing a device structure in a step following to the step in  FIG. 24  of the method of manufacturing the semiconductor device according to the embodiment of the present invention, which is used to explain the manufacturing method of the semiconductor device. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 
     FIG. 1  is a schematic diagram showing a structure of a pattern defect checking apparatus according to an embodiment of the present invention. 
   In  FIG. 1 , a photo mask  11  has a pattern of an LSI or the like formed thereon and is placed on an XY stage  12 . Light beams are radiated onto the photo mask  11  from a light source  13 . Those of the light beams, that are passed through the photo mask  11 , are focused on an image pickup device  15  via an objective lens  14  to form an optical image of the pattern. The optical image is measured by a sensing circuit  16 , and then converted into a digital signal by an A/D (Analog-to-Digital) converter  17 . The digital signal is transmitted to a defect check circuit  18 . The optical image may be obtained by using reflected light beams from the mask, or mixture light beams of the passed light beams and the reflected light beams, depending on characteristics of the mask. 
   On the other hand, a design data of the pattern is transmitted to a pattern expanding circuit  22  from a computer  21 , and the transmitted data is expanded into two-value or multi-value gradated data of pixels arranged in two-dimensional form in units of pixel by the pattern expanding circuit  22 . The gradated data (expanded pattern data) is transmitted to a reference data generating circuit  23 , and a reference data is obtained by the reference data generating circuit  23 . The reference data contains a change of a shape of the pattern caused by an etching process or the like carried out when the pattern is formed on the photo mask  11 . The reference data is transmitted to a defect check circuit  18 . 
   The sensed data obtained by sensing circuit  16  and transmitted to the defect check circuit  18  via the A/D converter  17  (i.e., a photo mask pattern image) is compared with reference data transmitted from the reference data generating circuit  23  by the defect check circuit  18  to check a defect of the pattern formed on the photo mask  11 . The XY stage  12  is movable in an XY direction by a stage control circuit  24 , which is operated by a command from the computer  21 . 
   Now, a description will be given with respect to a pattern defect checking method in accordance with the present embodiment, in particular, a reference data generating method, with reference to  FIGS. 2 to 18 . 
     FIG. 2  is a flow chart showing a pattern defect checking method in accordance with the present embodiment. 
     FIG. 3  is a graph showing a gradated data obtained by expanding a design data of a pattern, and  FIG. 4  is a graph showing a profile of the gradated data shown in  FIG. 3 , taken along the lines  4 - 4  shown in  FIG. 3 . 
   As shown in  FIG. 3 , the gradated data is a graphic data, and composed of rectangular portions. 
   First, as shown in  FIG. 3 , two-value or multi-value of pixels arranged in a two-dimensional form gradated data in units of pixel is obtained by expanding a design data of a pattern to be formed by the pattern expanding circuit  22  (step S 0 ). The gradated data is transmitted to the reference data generating circuit  23 . 
   The reference data generating circuit  23  carries out the following calculations sequentially. These calculations may be carried out by hardware of the reference data generator circuit  23  or may be carried out in accordance with a program by the computer  21 . 
   First, the following calculation (first processing step: step S 1 ) is carried out for the figures of the gradated data (graphic data) shown in  FIG. 3 .
 
 a ( i,j )=[ a ( i,j )+{ a ( i− 1, j )+ a ( i+ 1, j )+ a ( i,j− 1)+ a ( i,j+ 1)}/4+{ a ( i− 1, j− 1)+ a ( i+ 1, j+ 1)+ a ( i+ 1, j− 1)+ a ( i− 1, j+ 1)}/8]/2.5  (1)
 
   By carrying out this calculation, the pattern data shown in  FIG. 3  is transformed into pattern data (graphic data) shown in  FIG. 5 .  FIG. 6  is a graph showing a profile of the graphic data shown in  FIG. 5 , taken along the lines  6 - 6  shown in  FIG. 5 . 
   This calculation is referred to as a so-called convoluting integration. By carrying out this calculation, a first processing data is obtained. By this calculation, corner portions of the rectangular graphic shape are rounded, and each graphic shape is smoothened. In addition, the profile is also smoothened. A numeral “4” in formula (1) is an example of a parameter as a first coefficient. This parameter is optimized so that the pattern data obtained through the calculation according to formula (1) becomes as close to sensed data as possible. Accordingly, this numeral changes depending on a mask pattern. In addition, a numeral “8” in formula (1) is defined by “4”×2, and thus when parameter “4” changes, this numeral changes accordingly. 
   Following the calculation of formula (1) above, a calculation (second processing step: step S 2 ) shown below is carried out.
 
 a ( i,j )=max[{ a ( i,j )−0.1}/0.9,0]  (2)
 
By carrying out this calculation, a second processing data is obtained. That is, by carrying out this calculation, the pattern data (graphic data) shown in  FIG. 5  is transformed into a pattern data (graphic data) shown in  FIG. 7 .  FIG. 8  is a graph showing a profile of the graphic data shown in  FIG. 7 , taken along the line  8 - 8  shown in  FIG. 7 . By carrying out this calculation, a position of a boundary (in particular, an inclination of the bottom portion of the profile) can be changed.
 
   Here, with respect to max(Q, 0), 0 is selected when Q is equal to or smaller than 0. If Q exceeds 0, Q is selected. Therefore, formula (2) means that the gradation values of the pixels of the first processing data (i.e., pattern data shown in  FIG. 5 , obtained by carrying out calculation of formula (1)) is rounded up by a first threshold value “0”, to provide the second processing data. In addition, a single parameter in Formula (2) is “0.1”, and “0.9” is normalized by “1−0.1”. As is the case with formula (1), this parameter is also optimized so that the pattern data obtained through the calculation according to formula (2) becomes as close to sensed data as possible. Accordingly, this numeral changes depending on a mask pattern. 
   Next, a following calculation (third processing step: step S 3 ) is carried out to provide a third processed data.
 
 a ( i,j )=min{ a ( i,j )0.9,1}  (3)
 
   By carrying out this calculation, the pattern data (graphic data) shown in  FIG. 7  is transformed into a pattern data (graphic data) shown in  FIG. 9 .  FIG. 10  is a graph showing a profile of the graphic data shown in  FIG. 9 , taken along the line  10 - 10  shown in  FIG. 9 . By carrying out this calculation, a profile and position of the pattern end (in particular, an inclination of the top portion of the profile) can be adjusted. 
   With respect to min(Q, 1), 1 is selected when Q is equal to or larger than 1. If Q is smaller than 1, Q is selected. Therefore, formula (3) means that the gradation values of the pixels in the second processing data (i.e., pattern data shown in  FIG. 7 , obtained by carrying out calculation of formula (1)) are rounded down by a second threshold value “1”, to provide the third processing data. In addition, a single parameter in Formula (3) is “0.9”. As is the case with formulae (1) and (2), this parameter is also optimized so that the pattern data obtained through the calculation according to formula (3) becomes as close as possible to sensed data. Accordingly, this numeral changes depending on a mask pattern. 
   Thereafter, a following calculation (fourth processing step: step S 4 ) is carried out to provide a fourth processed data.
 
 a ( i,j )= a ( i,j ) 1.2   (4)
 
   Formula (4) means that gradated values of the pixels in the third processed data are squared by a second coefficient “1.2” to generate the fourth processed data. By carrying out this calculation, the pattern data (graphic data) shown in  FIG. 9  is transformed into a pattern data (graphic data) shown in  FIG. 11 .  FIG. 12  is a graph showing a profile of the graphic data shown in  FIG. 11 , taken along the line  12 - 12  shown in  FIG. 11 . By carrying out this calculation, a profile of the pattern end (in particular, an inclination of the top and the bottom portion of the profile) can be changed. 
   The profile position and/or inclination is changed in the second, third and fourth steps. A major change (resize) is made in the second and third processing steps, and a minor change (fine adjustment) is made in the fourth processing step. 
   Next, a following calculation (fifth processing step: step S 5 ) is carried out to provide a fifth processed data.
 
 a ( i,j )=[ a ( i,j )−{1− a ( i,j )}×0.1 1/2 ] 2   (5)
 
   By carrying out this calculation, the pattern data (graphic data) shown in  FIG. 11  is transformed into a pattern data (graphic data) shown in  FIG. 13 .  FIG. 14  is a graph showing a profile of the graphic data shown in  FIG. 13 , taken along the line  14 - 14  shown in  FIG. 13 . 
   Formula (5) means that gradated values obtained by calculating gradated values of the pixels in the fourth processed data by using a third coefficient “0.1” are squared to provide a fifth processed data. 
   By carrying out this calculation, it becomes possible to change a profile considering a phase effect in the case of using a half tone, for example. 
   After the step S 4  (step S 10 ), it is determined whether or not a phase effect is utilized. In the case of a general chrome mask that does not utilize the phase effect, this fifth processing step can be omitted. 
   Then, a following calculation (sixth processing step: step S 6 ) is carried out to generate a sixth processed data.
 
 a ( i,j )= a ( i,j )×210  (6)
 
   By carrying out this calculation, the pattern data (graphic data) shown in  FIG. 13  is transformed into a pattern data (graphic data) shown in  FIG. 15 .  FIG. 16  is a graph showing a profile of the graphic data shown in  FIG. 15 , taken along the line  16 - 16  shown in  FIG. 15 . 
   Formula (6) means that gradated values of the pixels in the fifth processed data are multiplied by a fourth coefficient “210” to generate a sixth processed data. 
   With the this calculation, a strength of the profile can be changed. That is, a dynamic range of the processed data can be set for the sensed data. 
   Subsequently, a following calculation (seventh processing step: step S 7 ) is carried out to provide a seventh processed data.
 
 a ( i,j )= a ( i,j )+10  (7)
 
   By carrying out this calculation, the pattern data (graphic data) shown in  FIG. 15  is transformed into a pattern data (graphic data) shown in  FIG. 17 .  FIG. 18  is a graph showing a profile of the graphic data shown in  FIG. 17 , taken along the line  18 - 18  shown in  FIG. 17 . 
   Formula (7) means that gradated values of the pixels in the sixth processed data are added to a fifth coefficient “10” to generate the seventh processed data. By carrying out this calculation, a level of the base can be changed. That is, an offset for the processed data can be arbitrarily set. 
   By carrying out the above calculations from the step S 1  to the step S 7 , the gradated data obtained from a design data of a pattern to be formed can be approximated to the sensed data. 
   Next, the obtained seventh processing data as shown in  FIG. 17  is defined as a reference data, and the sensor data is compared with the reference data by the defect check circuit  18 , to check pattern defect (step S 20 ). 
   In the above calculations, as described above, a multi-stepped calculation scheme is used in order to obtain a reference data from a pattern design data and a single parameter is used for each calculation. In this manner, it becomes possible to make parameter adjustment independently for each calculation to calculate a parameter that can minimize a difference between the reference data and the sensed data. Thus, there is no limitation to optical radiation such as the wavelength or NA (Numerical Aperture) of a light beam source of a checking apparatus. Therefore, a time required for calculation can be reduced, and also it becomes possible to provide a reference data with high accuracy of alignment with a sensed data for a short period of time. 
   Accordingly, also in a phase shift mask or a mask using an ultra-high resolution technique such as optical proximity effect correction, a level difference between the sensed data and the reference data is eliminated, and a precious defect check can be attained. 
   Next, a method of manufacturing a MOS (Metal Oxide Semiconductor) transistor as an example of semiconductor devices, by using a mask having been pattern defect checked according to the pattern defect checking method as above-described, will be explained. 
   As shown in  FIG. 19 , a gate insulating film  32  is formed on a silicon semiconductor substrate  31  by using a thermal oxidation method, a polysilicon film  33  is formed on the gate insulating film  32  by CVD (Chemical Vapor Deposition) method. After that, the polysilicon film  33  and the gate insulating film  32  are subjected to patterning to form a gate structure comprised of the polysilicon film  33  and the gate insulating film  32 . To form this gate structure, a photo resist layer  34  is formed on the polysilicon film  33 , and then the photo resist layer  34  is patterning-processed by lithography to form a photo resist pattern. 
   At this patterning of the photo resist layer  34 , use is made of a mask  35  having been pattern defect checked according to the pattern defect checking method as above-described. To be specific, the mask  35  is mounted above the silicon semiconductor substrate  31 , and light beams are radiated onto the silicon semiconductor substrate  31  via the mask  35  from a light beam source, not shown, to transfer a pattern of the mask  35  to the photo resist layer  34 . Subsequently, the photo resist layer  34  is patterning-processed by lithography so that a photo resist pattern  34  corresponding to the pattern of the mask  35  is formed, as shown in  FIG. 20 . 
   Next, as shown in  FIG. 21 , the polysilicon film  33  and the gate insulating film  32  are patterning-processed to form the gate structure comprised of the polysilicon film  33  and the gate insulating film  32 , by using the photo resist pattern  34  as an etching mask. Then, impurities are implanted into the silicon semiconductor substrate  31  to form source/drain regions  36 , by using the photo resist pattern  34 , the polysilicon film  33  (polysilicon electrode) and the gate insulating film  32 , as a mask. 
   Subsequently, the photo resist pattern  34  is removed by a known method. Then, as shown in  FIG. 22 , an interlayer insulating film  37  is formed over the silicon semiconductor substrate  31  by CVD method. Following this, openings are formed in the interlayer insulating film  37  for contact to the polysilicon electrode  33  and source/drain regions  36 . To form the openings, a photo resist layer  38  is formed on the interlayer insulating film  37 , and then the photo resist layer  38  is patterning-processed by lithography to form a photo resist pattern. 
   At this patterning of the photo resist layer  38 , use is made of a mask  39  having been pattern defect checked according to the pattern defect checking method as above-described. To be specific, the mask  39  is mounted above the silicon semiconductor substrate  31 , and light beams are radiated onto the silicon semiconductor substrate  31  via the mask  39  from a light beam source, not shown, to transfer a pattern of the mask  39  to the photo resist layer  38 . Subsequently, the photo resist layer  38  is patterning-processed by lithography so that a photo resist pattern  38  corresponding to the pattern of the mask  39  is formed, as shown in  FIG. 23 . 
   Next, as shown in  FIG. 24 , the interlayer insulating film  37  is patterning-processed to form the openings for contact to the polysilicon electrode  33  and source/drain regions  36 , by using the photo resist pattern  38  as an etching mask. 
   Subsequently, the photo resist pattern  38  is removed by a known method. Then, as shown in  FIG. 25 , contact metals  39  are formed in the openings for contact to the polysilicon electrode  33  and source/drain regions  36 , and wiring metals  40  contacting the contact metals  39  are formed on the interlayer insulating film  37  by a known method. With the manufacturing method, since a mask  35  having been pattern defect checked according to the pattern defect checking method as above-described is used, the transferred mask pattern has high alignment with the reference data transferred, resulting in providing high accuracy to the semiconductor device thus formed. 
   The present invention is not limited to the above-described embodiments. In the embodiments, although the calculations of formula (1) to formula (6) have been carried out each one time. However, the calculation number, calculation sequence and the coefficients used for each calculation can be changed so that approximation between the reference data and the sensor data is enhanced. Further, the reference data may be obtained for each mask or may be obtained for each typical pattern. 
   In addition, in the case where the pattern defect checking method according to the embodiment is applied to a general chrome mask that does not utilize a phase effect, the fifth processing step can be omitted. Further, although the sixth and seventh processing steps are steps to adjust the reference data to an output level of the detecting circuit, these processing steps are not necessarily required when the detecting circuit can adjust the level of the sensed data to the reference data. 
   Moreover, the above calculation method can be written as a program which can be executed by a computer, for example, in a recording medium such as a magnetic disk (such as a floppy (registered trademark) disk and a hard disk), an optical disk (such as a CD-ROM and a DVD), or a semiconductor memory. Also, the calculation method can be transmitted by a communication medium. A computer carrying out the above embodiments may be a computer, which reads a program recorded in a recording medium, and executes the above-described processing in accordance with the program. 
   Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.