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Effect of oxygen partial pressure on silicon single crystal growth by floating zone technique: surface oxidation and Marangoni flow
Author(s) -
Hibiya Taketoshi,
Asai Yoshihiko,
Sumiji Masanobu,
Kojima Toshiya
Publication year - 2003
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.200310076
Subject(s) - marangoni effect , partial pressure , striation , silicon , surface tension , analytical chemistry (journal) , single crystal , marangoni number , oxygen , crystal (programming language) , chemistry , materials science , mineralogy , crystallography , thermodynamics , metallurgy , composite material , chromatography , programming language , physics , organic chemistry , computer science
Silicon single crystals were grown by the floating‐zone method using an infrared image furnace in the wide range of oxygen partial pressure defined at the inlet of the furnace from 1×10 −2 Pa to 8.2×10 2 Pa ( P o 2 surface = 5.3 × 10 −24 Pa to 3.6 × 10 −14 Pa), so that the Marangoni number was changed from 2070 to 616. Degree of surface oxidation of the grown crystal was dependent on oxygen partial pressure of an ambient atmosphere. Striation pattern in almost all crystal shows a single frequency. At P o 2 inlet = 4.9 × 10 2 Pa ( P o 2 surface = 1.3 × 10 −14 Pa: imaginary Marangoni number of 700) precipitation of SiO 2 was observed at the melt surface. At P o 2 inlet = 8.2 × 10 2 Pa ( P o 2 surface = 3.6 × 10 −14 Pa: imaginary Marangoni number of 616), which is over the equilibrium oxygen partial pressure for a SiO 2 phase, the silicon specimen was polycrystallized and showed no growth striation. Temperature coefficient of surface tension |‐∂σ/∂ T | less than 0.25 × 10 −3 N/m‐K is not realistic, although many small values have been reported.