Laser processing device and laser light monitoring method
A laser processing device and a laser processing method that are capable of forming a high-quality semiconductor film are provided. An ELA device (excimer laser annealing device) ( 1 ) includes a laser oscillator ( 10 ) that generates laser light for forming a polysilicon film by irradiating an amorphous silicon film over a substrate to be processed with the laser light, a pulse measuring instrument ( 100 ) for detecting first partial light and second partial light contained in the laser light, and a monitoring device ( 60 ) for comparing a detection result of the first partial light with a detection result of the second partial light.
1 . A laser processing device comprising:
a laser generation device configured to generate laser light to be applied to an object to be processed;
a photodetection device configured to detect a first partial light and a second partial light contained in the laser light; and
a monitoring unit configured to generate a waveform for the first partial light and a waveform for the second partial light, and compare an area of the waveform of the first partial light with an area of the waveform of the second partial light.
2 . The laser processing device according to claim 1 , wherein the laser light is configured to crystallize an amorphous film over a substrate to form a crystallized film.
3 . The laser processing device according to claim 1 , wherein the laser light is gas laser light.
4 . The laser processing device according to claim 3 , wherein the laser light is excimer laser light.
5 . The laser processing device according to claim 1 , further comprising an optical system configured to divide the laser light into a plurality of divisional beams,
wherein the photodetection device detects a first divisional beam and a second divisional beam included in the plurality of divisional beams as the first partial light and the second partial light.
6 . The laser processing device according to claim 5 , wherein the photodetection device detects a first divisional beam group and a second divisional beam group included in the plurality of divisional beams as the first partial light and the second partial light.
7 . The laser processing device according to claim 1 , wherein the photodetection device comprises:
a first photodetector configured to detect the first partial light; and
a second photodetector configured to detect the second partial light.
8 . The laser processing device according to claim 7 , wherein the photodetection device comprises:
a first condenser lens configured to converge the first partial light onto a first photodetector; and
a second condenser lens configured to converge the second partial light onto a second photodetector.
9 . The laser processing device according to claim 7 , wherein the photodetection device further comprises a slit configured to transmit the first partial light and the second partial light therethrough.
10 . The laser processing device according to claim 1 , wherein the photodetection device comprises:
a slit configured to transmit the first partial light or the second partial light therethrough; and
a photodetector configured to detect the transmitted first partial light or second partial light.
11 . The laser processing device according to claim 10 , wherein the slit is a movable slit that can be driven so as to transmit the first partial light or the second partial light therethrough.
12 . The laser processing device according to claim 10 , wherein the photodetection device further comprises a condenser lens configured to converge the transmitted first partial light or second partial light onto the photodetector.
13 . The laser processing device according to claim 1 , wherein the monitoring unit determines values indicating variances between the areas of the waveforms.
14 . The laser processing device according to claim 13 , wherein each of the areas represents an energy in each respective waveforms.
15 . The laser processing device according to claim 13 , wherein the monitoring unit determines a difference between the variance values.
16 . The laser processing device according to claim 15 , further comprising a control unit configured to control a condition for generating the laser light in the laser generation device based on the differences in the variance values.
17 . The laser processing device according to claim 13 , further comprising a control unit configured to control a condition for generating the laser light in the laser generation device based on the variance values.
18 . The laser processing device according to claim 1 , further comprising a control unit configured to control a condition for generating the laser light in the laser generation device based on the comparison result.
19 . The laser processing device according to claim 18 , wherein the control unit controls an angle of a resonator mirror equipped in the laser generation device.
20 . A laser light monitoring method comprising:
(A) generating laser light to be applied to an object to be processed;
(B) detecting first partial light and second partial light contained in the laser light; and
(C) generating a waveform for the first partial light and a waveform for the second partial light, and comparing an area of the waveform of the first partial light with an area of the waveform of the second partial light.