Calculation method, storage medium, information processing apparatus, and measurement apparatus

A non-transitory computer-readable storage medium storing a program executable by a computer to execute a method of obtaining a shape of a measurement target surface, the method comprising:

• a first step of obtaining, while scanning a probe contacting the measurement target surface in a first direction, first shape measurement data of a line region of the measurement target surface, which represents a shape of the line region by detecting a position of the probe during scanning, and obtaining, while scanning the probe contacting the measurement target surface in a second direction different from the first direction, second shape measurement data of a line region of the measurement target surface, which represents a shape of the line region by detecting a position of the probe during scanning;
• a second step of obtaining first corrected shape data by correcting the first shape measurement data using a first correction parameter for correcting a first measurement error caused by scanning the probe in the first direction, and obtaining second corrected shape data by correcting the second shape measurement data using a second correction parameter for correcting a second measurement error caused by scanning the probe in the second direction;
• a third step of generating whole shape data representing a shape of the whole measurement target surface by synthesizing the first corrected shape data and the second corrected shape data;
• and
• a fourth step of correcting the first shape measurement data obtained in the first step while changing the first correction parameter, correcting the second shape measurement data obtained in the first step while changing the second correction parameter, obtaining a value of an evaluation function for evaluating the first corrected shape data and the second corrected shape data obtained in the second step, whenever the first correction parameter and the second correction parameter are changed, and determining the first correction parameter and the second correction parameter so that the value of the evaluation function falls within an allowable range.

An information processing apparatus, the apparatus comprising:

• a processor configured to obtain a shape of a measurement target surface by executing:
• a first task that obtains first shape measurement data, which is obtained while scanning a probe contacting the measurement target surface in a first direction, of a line region of the measurement target surface, which represents a shape of the line region by detecting a position of the probe during scanning, and obtains second shape measurement data, which is obtained while scanning the probe contacting the measurement target surface in a second direction different from the first direction, of a line region of the measurement target surface, which represents a shape of the line region by detecting a position of the probe during scanning;
• a second task that obtains first corrected shape data by correcting the first shape measurement data using a first correction parameter for correcting a first measurement error caused by scanning the probe in the first direction, and obtains second corrected shape data by correcting the second shape measurement data using a second correction parameter for correcting a second measurement error caused by scanning the probe in the second direction;
• a third task that generates whole shape data representing a shape of the whole measurement target surface by synthesizing the first corrected shape data and the second corrected shape data;
• and
• a fourth task that corrects the first shape measurement data obtained in the first task while changing the first correction parameter, corrects the second shape measurement data obtained in the first task while changing the second correction parameter, obtains a value of an evaluation function for evaluating the first corrected shape data and the second corrected shape data obtained in the second task, whenever the first correction parameter and the second correction parameter are changed, and determines the first correction parameter and the second correction parameter so that the value of the evaluation function falls within an allowable range.

A measurement apparatus for measuring a shape of a measurement target surface, the measurement apparatus comprising:

• a probe configured to measure the measurement target surface;
• and
• a control unit configured to obtain the shape of the measurement target surface by:
• obtaining first shape measurement data, which is obtained, while scanning the probe contacting the measurement target surface in a first direction, of a line region of the measurement target surface, which represents a shape of the line region by detecting a position of the probe during scanning, and obtaining second shape measurement data, which is obtained while scanning the probe contacting the measurement target surface in a second direction different from the first direction, of a line region of the measurement target surface, which represents a shape of the line region by detecting a position of the probe during scanning;
• obtaining first corrected shape data by correcting the first shape measurement data using a first correction parameter for correcting a first measurement error caused by scanning the probe in the first direction, and obtaining second corrected shape data by correcting the second shape measurement data using a second correction parameter for correcting a second measurement error caused by scanning the probe in the second direction;
• generating first whole shape data representing a shape of the whole measurement target surface by synthesizing the corrected shape data and the second corrected shape data;
• and
• correcting the obtained first shape measurement data while changing the first correction parameter, correcting the obtained second shape measurement data while changing the second correction parameter, obtaining a value of an evaluation function for evaluating the obtained first corrected shape data and the obtained second corrected shape data, whenever the first correction parameter and the second correction parameter are changed, and determining the first correction parameter and the second correction parameter so that the value of the evaluation function falls within an allowable range.