Grown-in Microdefects in a Slowly Grown Czochralski Silicon Crystal Observed by Synchrotron Radiation Topography

• Published in: Japanese Journal of Applied Physics Vol. 39; no. 11R; p. 6130
• Main Authors: Iida, Satoshi, Aoki, Yoshirou, Sugita, Yoshimitsu, Abe, Takao, Kawata, Hiroshi
• Format: Journal Article
• Language: English
• Published: 01.11.2000
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.39.6130

Grown-in microdefects of a slowly grown Czochralski (CZ) silicon crystal were studied by short wavelength synchrotron radiation topography and successfully visualized. It was shown that the microdefects had spherical strain fields, by comparing the defect images in the two topographs taken with the Bragg reflections perpendicular and parallel to the growth direction. The radial distributions of the microdefect size and density were measured from the defect images in the topographs. The misfit volume of the microdefects was approximately 1 ×10 -12 cm 3 at the central axis region of the crystal ingot, and decreased monotonically toward the peripheral region of the crystal. The density of the microdefects was approximately 300/cm 3 at the center of the crystal, increased toward the periphery and then decreased rapidly to almost zero in the very peripheral region approximately 7 mm from the surface of the crystal ingot. These radial distributions are discussed in connection with the self-interstitial atoms of silicon crystals.