Measuring devices, measuring methods, manufacturing methods of semiconductor devices, and program products

Abstract

This invention provides a measuring device that can reduce errors in thickness or temperature measurements using optical interference. The measuring device of one embodiment includes a light source, a spectrometer, a memory device, and a processor. The memory device stores a first correction table containing measured values ​​of thickness or temperature and their true values, and a second correction table containing measured values ​​of phase angle and their true values. The processor performs a Fourier transform on the spectroscopic waveform measured by the spectrometer; based on the amplitude peak position of the Fourier-transformed waveform, it calculates the thickness or temperature of the object being measured as the first measured value; based on the amplitude peak position of the Fourier-transformed waveform, it calculates the phase angle before phase expansion as the second measured value; it selects a plurality of first and second true value candidates corresponding to the first and second measured values ​​from the first and second correction tables respectively; and outputs the value of the first and second true value candidate that is the same or closest among the selected plurality of first and second true value candidates as the thickness or temperature of the object being measured.

Claims

1. A measuring device comprising: a light source configured to emit measuring light having a wavelength that transmits through an object to be measured; a spectrometer configured to measure a spectroscopic waveform of light reflected from the object to be measured by the measuring light; a memory device configured to store a first correction table containing measured values ​​of thickness or temperature and true values ​​of the thickness or temperature, and a second correction table containing measured values ​​of phase angle and true values ​​of the thickness or temperature; and a processor; wherein the processor is configured to: perform a Fourier transform on the spectroscopic waveform measured by the spectrometer; calculate the thickness or temperature of the object to be measured based on the amplitude peak position of the waveform after the Fourier transform, as a first measured value; calculate the phase angle before phase expansion based on the amplitude peak position of the waveform after the Fourier transform, as a second measured value; select a plurality of first true value candidates corresponding to the first measured value from the first correction table; and select a plurality of second true value candidates corresponding to the second measured value from the second correction table. The thickness or temperature of the object being measured will be output based on the value of the first true value candidate that is the same as or closest to the first true value candidate and the second true value candidate among the above-selected plurality of first true value candidates and the above-selected plurality of second true value candidates.

2. The measuring apparatus of claim 1, wherein the processor is further configured to generate the first correction table based on the relationship between the measured value of thickness or temperature calculated from the amplitude peak position obtained in the experimental range and the true value of the thickness or temperature, and to generate the second correction table based on the relationship between the measured value of the phase angle before phase expansion at the amplitude peak position obtained in the experimental range and the true value of the thickness or temperature.

3. The measuring device of claim 2, wherein the processor is further configured to extend each of the first correction table and the second correction table outside the experimental range based on the measured value of thickness or temperature calculated from the measured value of the amplitude peak position obtained from the experimental range, the measured value of the phase angle before phase expansion, and the regularity between the error of thickness or temperature.

4. A measurement method comprising: a light source configured to emit measurement light having a wavelength that transmits through an object to be measured; a spectrometer configured to measure the spectral waveform of light reflected from the object to be measured by the measurement light; and a memory device configured to store a first correction table containing measured values ​​of thickness or temperature and the true values ​​of the thickness or temperature, and a second correction table containing measured values ​​of phase angle and the true values ​​of the thickness or temperature; and comprising: performing a Fourier transform on the spectral waveform measured by the spectrometer; calculating the thickness or temperature of the object to be measured based on the amplitude peak position of the waveform after the Fourier transform, as a first measured value; calculating the phase angle before phase expansion based on the amplitude peak position of the waveform after the Fourier transform, as a second measured value; and selecting a plurality of first true value candidates corresponding to the first measured value from the first correction table. From the above-mentioned second correction table, a plurality of second true value candidates corresponding to the above-mentioned second measured value are selected; and the value of the first true value candidate and the second true value candidate that are the same or closest among the above-mentioned plurality of first true value candidates and the above-mentioned plurality of second true value candidates are output as the thickness or temperature of the above-mentioned measured object.

5. The measurement method of claim 4 further comprises: generating the first correction table based on the relationship between the measured value of thickness or temperature calculated from the amplitude peak position obtained in the experimental range and the true value of the thickness or temperature; and generating the second correction table based on the relationship between the measured value of the phase angle before phase expansion at the amplitude peak position obtained in the experimental range and the true value of the thickness or temperature.

6. The measurement method of claim 5 further comprises: based on the regularity between the measured value of thickness or temperature calculated from the measured value of the amplitude peak position obtained in the above-mentioned experimental range, the measured value of the phase angle before phase expansion, and the error of thickness or temperature, extending each of the above-mentioned first correction table and the above-mentioned second correction table outside the above-mentioned experimental range.

7. A method for manufacturing a semiconductor device comprising: a light source configured to emit measurement light having a wavelength that transmits through a measured object; a spectrometer configured to measure a spectroscopic waveform of light reflected from the measured object by the measurement light; and a memory device configured to store a first correction table containing measured values ​​of thickness or temperature and the true values ​​of the thickness or temperature, and a second correction table containing measured values ​​of phase angle and the true values ​​of the thickness or temperature; and further comprising: performing a Fourier transform on the spectroscopic waveform measured by the spectrometer; calculating the thickness or temperature of the measured object based on the amplitude peak position of the Fourier transformed waveform as a first measured value; calculating the phase angle before phase expansion based on the amplitude peak position of the Fourier transformed waveform as a second measured value; and selecting a plurality of first true value candidates corresponding to the first measured value from the first correction table. From the above-mentioned second correction table, a plurality of second true value candidates corresponding to the above-mentioned second measured value are selected; and the value of the first true value candidate and the second true value candidate that are the same or closest among the above-mentioned plurality of first true value candidates and the above-mentioned plurality of second true value candidates are output as the thickness or temperature of the above-mentioned measured object.

8. The method for manufacturing a semiconductor device as claimed in claim 7 further comprises: generating the first correction table based on the relationship between the measured value of thickness or temperature calculated from the amplitude peak position obtained in the experimental range and the true value of the thickness or temperature; and generating the second correction table based on the relationship between the measured value of the phase angle before phase expansion at the amplitude peak position obtained in the experimental range and the true value of the thickness or temperature.

9. The method for manufacturing a semiconductor device as claimed in claim 8 further comprises: extending each of the first correction table and the second correction table beyond the experimental range based on the measured values ​​of thickness or temperature calculated from the amplitude peak position obtained from the above-mentioned experimental range, the measured values ​​of phase angle before phase expansion, and the regularity between the errors of thickness or temperature.

10. A program product comprising a light source configured to emit measuring light having a wavelength that transmits through a measured object, a spectrometer configured to measure the spectral waveform of light reflected from the measured object by the measuring light, and a memory device configured to store a first correction table containing measured values ​​of thickness or temperature and the true values ​​of the thickness or temperature, and a second correction table containing measured values ​​of phase angle and the true values ​​of the thickness or temperature; and causing a computer to execute: performing a Fourier transform on the spectral waveform measured by the spectrometer; calculating the thickness or temperature of the measured object based on the amplitude peak position of the waveform after the Fourier transform, as a first measured value; calculating the phase angle before phase expansion based on the amplitude peak position of the waveform after the Fourier transform, as a second measured value; and selecting a plurality of first true value candidates corresponding to the first measured value from the first correction table. From the above-mentioned second correction table, a plurality of second true value candidates corresponding to the above-mentioned second measured value are selected; and the value of the first true value candidate and the second true value candidate that are the same or closest among the above-mentioned plurality of first true value candidates and the above-mentioned plurality of second true value candidates are output as the thickness or temperature of the above-mentioned measured object.

11. The program product of claim 10 further comprises: generating the first correction table based on the relationship between the measured value of thickness or temperature calculated from the amplitude peak position obtained in the experimental range and the true value of the thickness or temperature; and generating the second correction table based on the relationship between the measured value of the phase angle before phase expansion at the amplitude peak position obtained in the experimental range and the true value of the thickness or temperature.

12. The program product of claim 11 further comprises: based on the regularity between the measured value of thickness or temperature calculated from the measured value of the amplitude peak position obtained in the above-mentioned experimental range, the measured value of the phase angle before phase expansion, and the error of thickness or temperature, extending each of the above-mentioned first correction table and the above-mentioned second correction table outside the above-mentioned experimental range.

Images