Czochralski-growth of germanium crystals containing high concentrations of oxygen impurities

• Published in: Journal of crystal growth 2010-09, Vol.312 (19), p.2783-2787
• Main Authors: Taishi, Toshinori, Ise, Hideaki, Murao, Yu, Osawa, Takayuki, Suezawa, Masashi, Tokumoto, Yuki, Ohno, Yutaka, Hoshikawa, Keigo, Yonenaga, Ichiro
• Format: Article
• Language: English
• Subjects: A1. Doping; A1. Oxygen impurity; A2. Czochralski method; A2. Single crystal growth; B2. Semiconducting germanium; Condensed matter: structure, mechanical and thermal properties; Covering; Cross-disciplinary physics: materials science; rheology; Crystal growth; Crystals; Defects and impurities in crystals; microstructure; Density; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Germanium; Growth from melts; zone melting and refining; Linear defects: dislocations, disclinations; Liquids; Materials science; Melts; Methods of crystal growth; physics of crystal growth; Oxides; Physics; Solubility, segregation, and mixing; phase separation; Spectra; Structure of solids and liquids; crystallography
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2010.05.045

Oxygen-containing germanium (Ge) single crystals with low density of grown-in dislocations were grown by the Czochralski (CZ) technique from a Ge melt, both with and without a covering by boron oxide (B 2O 3) liquid. Interstitially dissolved oxygen concentrations in the crystals were determined by the absorption peak at 855 cm −1 in the infrared absorption spectra at room temperature. It was found that oxygen concentration in a Ge crystal grown from melt partially or fully covered with B 2O 3 liquid was about 10 16 cm −3 and was almost the same as that in a Ge crystal grown without B 2O 3. Oxygen concentration in a Ge crystal was enhanced to be greater than 10 17 cm −3 by growing a crystal from a melt fully covered with B 2O 3; with the addition of germanium oxide powder, the maximum oxygen concentration achieved was 5.5×10 17 cm −3. The effective segregation coefficients of oxygen in the present Ge crystal growth were roughly estimated to be between 1.0 and 1.4.