TY - JOUR
T1 - Czochralski growth techniques of germanium crystals grown from a melt covered partially or fully by liquid B 2O 3
AU - Taishi, Toshinori
AU - Hashimoto, Yoshio
AU - Ise, Hideaki
AU - Murao, Yu
AU - Ohsawa, Takayuki
AU - Yonenaga, Ichiro
N1 - Funding Information:
This work was supported in part by a Grant-in-Aid for Science Research ( 20760003 and 22686002 ) from the Ministry of Education, Science, Sports and Culture. This work was also performed under the Inter-university Cooperative Research Program of the Institute for Materials Research, Tohoku University.
PY - 2012/12/1
Y1 - 2012/12/1
N2 - We propose two unique Czochralski (CZ) techniques for growing germanium (Ge) crystals with an extremely low dislocation density and high interstitial oxygen concentration ([Oi]) using boron oxide (B 2O 3) and a silica crucible. When a Ge melt is partially covered with liquid B 2O 3, but only on the outer region of the melt surface, germanium-oxide (GeO 2)-related particles forming naturally in the melt are effectively dissolved by the liquid B 2O 3. The clean central portion of the melt produces dislocation-free undoped or Ga-doped Ge crystals. In addition, Ge crystals with [Oi] up to 6×10 17 cm -3 can be grown from a melt fully covered by liquid B 2O 3 with added GeO 2 powder. The reaction and transportation of oxygen atoms during the growth process using B 2O 3 was investigated, revealing that liquid B 2O 3 acts like a catalyst without heavy contamination of the growing Ge crystal by B and Si atoms.
AB - We propose two unique Czochralski (CZ) techniques for growing germanium (Ge) crystals with an extremely low dislocation density and high interstitial oxygen concentration ([Oi]) using boron oxide (B 2O 3) and a silica crucible. When a Ge melt is partially covered with liquid B 2O 3, but only on the outer region of the melt surface, germanium-oxide (GeO 2)-related particles forming naturally in the melt are effectively dissolved by the liquid B 2O 3. The clean central portion of the melt produces dislocation-free undoped or Ga-doped Ge crystals. In addition, Ge crystals with [Oi] up to 6×10 17 cm -3 can be grown from a melt fully covered by liquid B 2O 3 with added GeO 2 powder. The reaction and transportation of oxygen atoms during the growth process using B 2O 3 was investigated, revealing that liquid B 2O 3 acts like a catalyst without heavy contamination of the growing Ge crystal by B and Si atoms.
KW - A1. Doping
KW - A1. Impurities
KW - A2. Czochralski method
KW - B2. Semiconducting germanium
UR - http://www.scopus.com/inward/record.url?scp=84867489063&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84867489063&partnerID=8YFLogxK
U2 - 10.1016/j.jcrysgro.2011.11.051
DO - 10.1016/j.jcrysgro.2011.11.051
M3 - Article
AN - SCOPUS:84867489063
VL - 360
SP - 47
EP - 51
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
SN - 0022-0248
IS - 1
ER -