Method for correcting critical dimension of phase shift mask and method for manufacturing the same

1. A method for correcting the critical dimension (CD) of a phase shift mask, comprising:

calculating an intensity slope quantifying a slope of an intensity waveform of secondary electrons emitted by scanning an electron beam spot to a hard mask pattern on a phase shift mask on a substrate;

extracting a delta critical dimension (CD) value, which is equal to a CD difference between the phase shift pattern and the hard mask pattern, as a delta CD value corresponding to the intensity slope; and

correcting the CD of the phase shift mask by using the extracted delta CD value.

2. The method of claim 1 , wherein the calculating of the intensity slope comprises:

a first measurement operation of measuring the CD of the hard mask pattern on the basis of a first intensity value of the secondary electrons;

a second measurement operation of measuring the CD of the hard mask pattern on the basis of a second intensity value of the secondary electrons; and

calculating a slope of a straight line, which passes through first coordinates comprised of the first intensity value and a first measurement value measured by the first measurement operation and second coordinates comprised of the second intensity value and a second measurement value measured by the second measurement operation, as the intensity slope.

3. The method of claim 2 , wherein the first measurement operation and the second measurement operation are performed using a scanning electron microscopy (SEM) equipment.

4. The method of claim 2 , wherein the first intensity value is set to approximately 80% of the maximum intensity of the secondary electrons, and the second intensity value is set to approximately 20% of the maximum intensity of the secondary electrons.

5. The method of claim 1 , wherein the extracting of the delta CD value is performed using a functional equation with variables of the intensity slope and the delta CD.

6. The method of claim 5 , wherein the functional equation is prepared in advance through a plurality of test operations.

7. The method of claim 6 , wherein the preparing of the functional equation comprises:

a first operation of measuring a first CD value and a second CD value for the hard mask pattern on the basis of a first intensity value and a second intensity value of the secondary electrons that are different from each other;

a second operation of calculating an intensity slope by using the first intensity value, the second intensity value, the first CD value and the second CD value;

a third operation of calculating a delta CD by measuring the CD of the phase shift pattern after removing the hard mask pattern; and

defining a functional equation applied to the respective delta CDs corresponding to the intensity slopes obtained by repeating the first operation, the second operation and the third operation a predetermined number of times.

8. The method of claim 1 , wherein the phase shift pattern is additionally etched using a plasma-based etching process.

9. A method for manufacturing a phase shift mask, comprising:

forming a hard mask pattern on a phase shift layer on a substrate;

forming a phase shift pattern by etching the phase shift layer by using the hard mask pattern as an etch mask;

calculating an intensity slope quantifying a slope of an intensity waveform of secondary electrons emitted by scanning an electron beam spot to the hard mask pattern;

extracting a delta critical dimension (CD) value, which is equal to a CD difference between the phase shift pattern and the hard mask pattern, as a delta CD value corresponding to the intensity slope;

correcting the CD of the phase shift mask by using the extracted delta CD value; and

removing the hard mask pattern.

10. The method of claim 9 , wherein the calculating of the intensity slope comprises:

a first measurement operation of measuring the CD of the hard mask pattern on the basis of a first intensity value of the secondary electrons;

a second measurement operation of measuring the CD of the hard mask pattern on the basis of a second intensity value of the secondary electrons; and

calculating a slope of a straight line, which passes through first coordinates comprised of the first intensity value and a first measurement value measured by the first measurement operation and second coordinates comprised of the second intensity value and a second measurement value measured by the second measurement operation, as the intensity slope.

11. The method of claim 10 , wherein the first measurement operation and the second measurement operation are performed using a scanning electron microscopy (SEM) equipment.

12. The method of claim 10 , wherein the first intensity value is set to approximately 80% of the maximum intensity of the secondary electrons, and the second intensity value is set to approximately 20% of the maximum intensity of the secondary electrons.

13. The method of claim 9 , wherein the extracting of the delta CD value is performed using a functional equation with variables of the intensity slope and the delta CD.

14. The method of claim 13 , wherein the functional equation is prepared in advance through a plurality of test operations.

15. The method of claim 14 , wherein the preparing of the functional equation comprises:

a first operation of measuring a first CD value and a second CD value for the hard mask pattern on the basis of a first intensity value and a second intensity value of the secondary electrons that are different from each other;

a second operation of calculating an intensity slope by using the first intensity value, the second intensity value, the first CD value and the second CD value;

a third operation of calculating a delta CD by measuring the CD of the phase shift pattern after removing the hard mask pattern; and

defining a functional equation applied to the respective delta CDs corresponding to the intensity slopes obtained by repeating the first operation, the second operation and the third operation a predetermined number of times.

16. The method of claim 9 , wherein the phase shift pattern is additionally etched using a plasma-based etching process.

17. The method of claim 9 , wherein the phase shift layer is formed using a molybdenum silicon film.

18. The method of claim 9 , wherein the hard mask pattern is formed using a chrome film.