Deformation and improvement of the ir transmission of single-crystal silicon by direct current heating

We confirmed that the deformation occurred at about 800 °C when CZ-Si was pressure and heat treated by a pulse-heating- method, spark plasma sintering (SPS), while at the same time, the absorption peak of silicon single crystal produced using the Czochralski process (CZ-Si), which was a major issue for infrared transparent material in the vicinity of 9 μm, was also confirmed to have been reduced within a short time. The absorption coefficient in the vicinity of 9 μm, which was derived from the interstitial oxygen, decreased the most at 800 °C, and the absorption derived from the stretching mode of Si-O observed in the vicinity of 9.7 μm reached its maximum at 800 °C. This is considered to have been due to the migration of interstitial oxygen via clusters to change the material into amorphous SiO₂. It was confirmed that the impact of the applied pressure direction was relative to crystal orientation on the peak of 9 μm. It was also found that the deformation was the maximum from the (110) plane, that the change in absorption coefficients before and after deformation was the largest, and that the relationship turned out to be (110)> (100)> (111). The dislocation lines in the sample after the deformation of the (100) plane were observed using EBSD, and the polarization dependencies of transmittance in the infrared region were measured for the planes parallel and perpendicular to the applied pressure.