Pattern data generating apparatus and method for inspecting defects in fine patterns in a photomask or semiconductor wafer

A method of generating a gray scale pattern represented in units of pixels comprising the steps of:

• inputting pattern data including a pattern position and a pattern size at an accuracy of 1/n (n:
• integer) of a pixel, the pattern data representing a design pattern prepared by a pattern designer;
• casting the design pattern to a plurality of arrayed squares each having a predetermined size and divided into a plurality of segments arranged in a matrix:
• calculating occupation ratios defining how much of each square is occupied by the pattern data in relation to how many segments of each square are occupied by the pattern data;
• and
• outputting a plurality of gray scale level data representing 0 to n gray scale levels corresponding to the occupation ratios.

A method of generating a gray scale pattern represented in units of pixels comprising the steps of:

• inputting pattern data including a figure having a pattern shape, a pattern position and a pattern size at an accuracy of at least 1/n (n:
• integer) of a pixel, when a pattern corresponding to the pattern data is formed of line segments extending in a X-direction, a Y-direction and an incline direction of 45°, the pattern data representing a design pattern prepared by a pattern designer;
• casting the figure to a plurality of arrayed squares each having a predetermined pixel size and divided into a plurality of segments arranged in a matrix;
• calculating occupation ratios defining how much of each square is occupied by the figure in relation to how many segments of each square are occupied by the figure;
• and
• outputting a plurality of gray scale level data representing 0 to n gray scale levels corresponding to the occupation ratios, respectively.

A pattern inspection machine comprising:

• an image acquisition section configured to irradiate light having an appropriate wavelength on a specimen on which a pattern is formed, and acquiring measurement data corresponding to a pattern image received by a photosensor;
• a memory configured to store pattern design data used to form the pattern on the specimen, the pattern data representing a design pattern prepared by a pattern designer;
• a data development/generation section configured to develop every pixel of the pattern design data read out from the memory;
• and
• a determination section configured to compare data obtained by filtering the data developed by the data development section with the measurement pattern data, and determining the presence/absence of defect of the pattern formed on the specimen,
• wherein the memory stores light shield pattern design data used to form a light shield pattern on the specimen and phase shift pattern design data used to form a phase shift pattern so as to define the light shield pattern design data and the phase shift pattern design data on the same coordinate system and allow identification of the light shield pattern design data and the phase shift pattern data, the phase shift pattern design data being multivalue data, and
• said data development/generation section comprises a light shield pattern design data generation circuit and a phase shift pattern design data generation circuit, each of which comprises identification means for identifying a light shield pattern or a phase shift pattern on the basis of the light shield pattern design data and the phase shift pattern design data, amplitude adjusting means for determining an amplitude and offset of a brightness signal for each predetermined description unit on the basis of an identification signal from said identification means, pattern means for allowing bit weighting, inversion and a sign to be variable on the basis of the brightness signal from said amplitude adjustment means, a pattern memory for storing a predetermined pattern range of a bit string generated by said pattern means, pattern memory readout means for performing sequential read access to said pattern memory in accordance with an inspection progress, and calculation means for synthesizing data from said respective data generation circuits for each data type combination in accordance with a predetermined calculation method, and outputting a synthesis result.

A pattern data generating apparatus comprising:

• a storage configured to store design data;
• a decoder configured to obtain a decoded figure having a figure shape, a figure position and a figure size from each of the design pattern data read out from said storage;
• a casting section configured to cast the decoded figure to a plurality of arrayed squares each having a predetermined size and divided into a plurality of segments arranged in a matrix;
• a computing section configured to compute occupation ratios defining how much of each square is occupied by the figure in relation to how many segments of each square are occupied by the figure;
• and
• an output section to output a plurality of gray scale level data representing 0 to n gray scale levels corresponding to the occupation ratios, respectively;
• a pattern memory section configured to store the gray scale level data from said output section by a predetermined range;
• and
• a readout section configured to read out the gray scale level data of each of the squares from said pattern memory section, and
• wherein said output section comprises a plurality of pattern generators for generating the gray scale level data, said pattern memory comprises a plurality of pattern memories respectively corresponding to said pattern generators, and which further comprises a data distribution arbitrator for distributing input data so as to cause said plurality of pattern generators to perform parallel processing, and a pattern data adder for, in read accessing of said plurality of pattern memories, adding values of squares having identical coordinates to obtain a sum and outputting the sum to said readout section.

A pattern inspection machine comprising:

• an image acquisition section configured to irradiate light having an appropriate wavelength on a specimen on which a pattern is formed, and acquire measurement data corresponding to a pattern image received by a photosensor;
• a memory configured to store pattern design data used to form the pattern on the specimen;
• a data development/generation section configured to develop every pixel of the pattern design data read out from the memory;
• and
• a determination section configured to compare data obtained by filtering the data developed by the data development section with the measurement pattern data, and determine the presence/absence of a defect of the pattern formed on the specimen,
• wherein the memory stores light shield pattern design data used to form a light shield pattern on the specimen and phase shift pattern design data used to form a phase shift pattern so as to define the light shield pattern design data and the phase shift pattern design data on the same coordinate system and allow identification of the light shield pattern design data and the phase shift pattern data, and
• said data development/generation section comprises a light shield pattern design data generation circuit and a phase shift pattern design data generation circuit, each of which comprises identification means for identifying the light shield pattern or the phase shift pattern, amplitude adjusting means for determining an amplitude and offset of a brightness signal for each predetermined description unit on the basis of an identification signal from said identification means, pattern means for allowing bit weighting, inversion and a sign to be variable on the basis of the brightness signal from said amplitude adjustment means, a pattern memory for storing a predetermined pattern range of a bit string generated by said pattern means, pattern memory readout means for performing sequential read access to said pattern memory in accordance with an inspection progress, and calculation means for synthesizing data from said respective data generation circuits for each data type combination in accordance with a predetermined calculation method, and outputting a synthesis result, and
• wherein said calculation means calculates the data by the following relation:
• k1d1+k2d2 for 0<k1<1 and −1<k2≦1
• where d1 is chromium data, d2 is phase shift data, and k1 and k2 are coefficients.

A method a generating a pattern data comprising the steps of:

• storing in a storage a plurality of design pattern data prepared by a pattern designer and representing a design pattern;
• and
• generating a decoded figure having a figure shape, a figure position and a figure size from each of the design pattern data read out from said storage;
• casting the decoded figure to a plurality of arrayed squares each having a predetermined size and divided into a plurality of segments arranged in a matrix;
• computing occupation ratios defining how much of each square is occupied by the figure in relation to how many segments of each square are occupied by the figure how each of the squares is occupied by the figure;
• and
• outputting a plurality of gray scale level data representing 0 to n gray scale levels corresponding to the occupation ratios, respectively.

A method of inspecting a pattern comprising the steps of:

• irradiating light having an appropriate wavelength on a specimen on which a pattern is formed, to obtain measurement data corresponding to a pattern image received by a photosensor;
• storing, in a storage, pattern design data used to form the pattern on the specimen, the pattern data representing a design pattern prepared by a pattern designer;
• developing every pixel of the pattern design data read out from the storage;
• and
• comparing data obtained by filtering the data developed by the developing step with the measurement pattern data, to determine the presence/absence of a defect of the pattern formed on the specimen,
• wherein the storing step includes storing light shield pattern design data used to form a light shield pattern on the specimen and phase shift pattern design data used to form a phase shift pattern so as to define the light shield pattern design data and the phase shift pattern design data on the same coordinate system and allow identification of the light shield pattern design data and the phase shift pattern data, the phase shift pattern design data being multivalue data, and
• said developing step includes identifying a light shield pattern or a phase shift pattern, determining an amplitude and offset a brightness signal for each predetermined description unit on the basis of identification result, allowing bit weighting, inversion and a sign to be variable on the basis of the brightness signal, storing in a pattern memory a predetermined pattern range of a bit string, performing sequential read access to said pattern memory in accordance with an inspection progress, and synthesizing data obtained for each data type combination in accordance with a predetermined calculation method, and outputting a synthesis result.

A method of generating pattern data comprising the steps of:

• storing design data prepared by a pattern designer in a storage;
• generating a decoded figure having a figure shape, a figure position and a figure size from each of the design pattern data read out from said storage;
• casting the decoded figure to a plurality of arrayed squares each having a predetermined size and divided into a plurality of segments arranged in a matrix;
• computing occupation ratios defining how much of each square is occupied by the figure in relation to how many segments of each square are occupied by the figure;
• and
• outputting a plurality of gray scale level data representing 0 to n gray scale levels corresponding to the occupation ratios, respectively;
• storing the gray scale level data in the storage by a predetermined range;
• and
• reading out gray scale level data of each of the squares from the storage;
• and
• adding values of squares having identical coordinates to obtain a sum, in read-accessing.

A pattern data generating apparatus comprising:

• a storage configured to store a plurality of design pattern data prepared by a pattern designer and representing a design pattern;
• and
• a decoder configured to obtain a decoded figure having a figure shape, a figure position and a figure size from each of the design pattern data read out from said storage;
• a casting section configured to cast the decoded figure to a plurality of arrayed squares each having a predetermined size;
• a computing section configured to compute how each of the squares is occupied by the figure to obtain occupation ratios;
• an output section to output a plurality of gray value data representing the occupation ratios, respectively,
• a pattern memory section configured to store the gray value data from said output section by a predetermined range, and a readout section configured to read out the gray value data from said memory section, and
• an accumulative write section configured to read out the gray value data already present in the squares before new data is written in said pattern memory section, adding the readout gray value data and the new data to obtain sums, and writing the sums in the square, and
• wherein said cumulative write section has an upper limit clamp function of writing a predetermined threshold value when the sums exceed the threshold value.

A pattern data generating apparatus comprising:

• a storage configured to store a plurality of design pattern data prepared by a pattern designer and representing a design pattern;
• and
• a decoder configured to obtain a decoded figure having a figure shape, a figure position and a figure size from each of the design pattern data read out from said storage;
• a casting section configured to cast the decoded figure to a plurality of arrayed squares each having a predetermined size;
• a computing section configured to compute how each of the squares is occupied by the figure to obtain occupation ratios;
• an output section to output a plurality of gray value data representing the occupation ratios, respectively,
• a pattern memory section configured to store the gray value data from said output section by a predetermined range, and a readout section configured to read out the gray value data from said memory section, and
• wherein said pattern generating section comprises a plurality of pattern generators for generating multivalue level bit pattern data, said pattern memory comprises a plurality of pattern memories respectively corresponding to said pattern generators, and which further comprises a data distribution arbitrator for distributing input data so as to cause said plurality of pattern generators to perform parallel processing, and a pattern data adder for, when said plurality of pattern memories are to be read-accessed, adding values of squares having identical coordinates to obtain a sum and outputting the sum to said readout section.

A pattern inspection machine comprising:

• an image acquisition section configured to irradiate light having an appropriate wavelength on a specimen on which a pattern is formed, and acquiring measurement data corresponding to a pattern image received by a photosensor;
• a memory configured to store pattern design data used to form the pattern on the specimen, the pattern data representing a design pattern prepared by a pattern designer;
• a data development/generation section configured to develop every pixel of the pattern design data read out from the memory;
• and
• a determination section configured to compare data obtained by filtering the data developed by the data development section with the measurement pattern data and determining the presence/absence of a defect of the pattern formed on the specimen,
• wherein the memory stores light shield pattern design data used to form a light shield pattern on the specimen and phase shift pattern design data used to form a phase shift pattern so as to define the light shield pattern design data and the phase shift pattern design data on the same coordinate system and allow identification of the light shield pattern design data and the phase shift pattern data, the phase shift pattern design data being multivalue data, and
• said data development/generation section comprises a light shield pattern design data generation circuit and a phase shift pattern design data generation circuit, each of which comprises identification means for identifying a light shield pattern or a phase shift pattern, amplitude adjusting means for determining an amplitude and offset of a brightness signal for each predetermined description unit on the basis of an identification signal from said identification means patted means for allowing bit weighting, inversion and a sign to be variable on the basis of the brightness signal from said amplitude adjustment means, a pattern memory for storing a predetermined pattern range of a bit string generated by said pattern means, pattern memory readout means for performing sequential read access to said pattern memory in accordance with an inspection progress, and calculation means for synthesizing data from said respective data generation circuits for each data type combination in accordance with a predetermined calculation method, and outputting a synthesis result, and wherein
• said calculation means calculates the data by the following relation:
• k1d1+k2d2 for 0<k1<1 and −1<k2≦1
• where d1 is chromium data, d2 is phase shift data, and k1 and k2 are coefficients.

A pattern inspection machine comprising:

• an image acquisition section configured to irradiate light having an appropriate wavelength on a specimen on which a pattern is formed, and acquiring measurement data corresponding to a pattern image received by a photosensor;
• a memory configured to store pattern design data used to form the pattern on a specimen, the pattern data representing a design pattern prepared by a pattern designer;
• a data development/generation section configured to develop every pixel of the pattern design data read out from the memory;
• and
• a determination section configured to compare data obtained by filtering the data developed by the data development section with the measurement pattern data, and determining the presence/absence of a defect of the pattern formed on the specimen,
• wherein the memory stores light shield pattern design data used to form a light shield pattern on the specimen and phase shift pattern design data used to form a phase shift pattern so as to define the light shield pattern design data and the phase shift pattern design data on the same coordinate system and allow identification of the light shield pattern design data and the phase shift pattern data, the phase shift pattern design data being multivalue data;
• said data development/generation section comprises a light shield pattern design data generation circuit and a phase shift pattern design data generation circuit, each of which comprises identification means for identifying a light shield pattern or a phase shift pattern, amplitude adjusting means for determining an amplitude and offset of a brightness signal for each predetermined description unit on the basis of an identification signal from said identification means, pattern means for allowing bit weighting, inversion and a sign to be variable on the basis of the brightness signal from said amplitude adjustment means, a pattern memory for storing a predetermined pattern range of a bit string generated by said pattern means, pattern memory readout means for performing sequential read access to said pattern memory in accordance with an inspection progress, and calculation means for synthesizing data from said respective data generation circuits for each data type combination in accordance with a predetermined calculation method, and outputting a synthesis result;
• and
• said cumulative write means of said data development/generation section has an upper limit clamp function of writing a predetermined threshold value, when the sum exceeds the predetermined threshold value.

A pattern inspection machine comprising:

• an image acquisition section configured to irradiate light having an appropriate wavelength on a specimen on which a pattern is formed, and acquiring measurement data corresponding to a pattern image received by a photosensor;
• a memory configured to store pattern design data used to form the pattern on the specimen, the pattern data representing a design pattern prepared by a pattern designer;
• a data development/generation section configured to develop every pixel of the pattern design data read out from the memory;
• and
• a determination section configured to compare data obtained by filtering the data developed by the data development section with the measurement pattern data, and determining the presence/absence of a defect of the pattern formed on the specimen,
• wherein the memory stores light shield pattern design data used to form a light shield pattern on the specimen and phase shift pattern design data used to form a phase shift pattern so as to define the light shield pattern design data and the phase shift pattern design data on the same coordinate system and allow identification of the light shield pattern design data and the phase shift pattern data, the phase shift pattern design data being multivalue data;
• said data development/generation section comprises a light shield pattern design data generation circuit and a phase shift pattern design data generation circuit each of which comprises identification means for identifying a light shield pattern or a phase shift pattern amplitude adjusting means for determining an amplitude and offset of a brightness signal for each predetermined description unit on the basis of an identification signal from said identification means, pattern means for allowing bit weighting, inversion and a sign to be variable on the basis of the brightness signs from said amplitude adjustment means, a pattern memory for storing a predetermined pattern rage of a bit string generated by said pattern means, pattern memory readout means for performing sequential read access to said pattern memory in accordance with an inspection progress, and calculation means for synthesizing data from said respective data generation circuits for each data type combination in accordance with a predetermined calculation method, and outputting a synthesis result;
• and
• said data development/generation section comprises a plurality of pattern generators and a plurality of pattern memories, and said specimen inspection machine further comprises data distribution arbitration means for distributing input data so as to cause said plurality of pattern generators to efficiently perform parallel processing, and pattern adding means for adding bit strings having identical coordinates to obtain a sum and outputting the sum to said pattern memory readout means, when said plurality of pattern memories are to be read-accessed.

A pattern data generating apparatus comprising:

• a storage configured to store design data;
• a decoder configured to obtain a decoded figure having a figure shape, a figure position and a figure size from each of the design pattern data read out from said storage;
• a casting section configured to cast the decoded figure to a plurality of arrayed squares each having a predetermined size;
• a computing section configured to compute how each of the squares is occupied by the figure to obtain occupation ratios, and;
• an output section to output a plurality of gray value data representing the occupation ratios, respectively;
• a pattern memory section configured to store the gray value data from said output section by a predetermined range;
• and
• a readout section configured to read out the gray value data of each of the squares from said pattern memory section, and
• wherein said output section comprises a plurality of pattern generators for generating multivalue level bit pattern data, said pattern memory comprises a plurality of pattern memories respectively corresponding to said patterns, generators, and which further comprises a data distribution arbitrator for distributing input data so as to cause said plurality of pattern generators to perform parallel processing, and a pattern data adder for, in read accessing of said plurality of pattern memories, adding values of squares having identical coordinates to obtain a sum and outputting the sum to said readout section, and
• said pattern data adder has an upper limit clamp function of outputting a predetermined threshold value to said readout section when the sum exceeds the predetermined threshold value.