scholarly journals Relationship between Dislocation Density and Oxygen Concentration in Silicon Crystals during Directional Solidification

Crystals ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 244 ◽  
Author(s):  
Tomoro Ide ◽  
Hirofumi Harada ◽  
Yoshiji Miyamura ◽  
Masato Imai ◽  
Satoshi Nakano ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Directional Solidification ◽  
Oxygen Concentration ◽  
Silicon Crystals

Control of Oxygen Content in Heavily Sb-Doped CZ Si Crystal by Adjusting Ambient Pressure

1995 ◽  
Vol 378 ◽  
Author(s):  
Koji Izunome ◽  
Xinming Huang ◽  
Shiniji Togawa ◽  
Kazutaka Terashima ◽  
Shigeyuki Kimura
Keyword(s):  
Single Crystals ◽  
Gas Phase ◽  
Oxygen Concentration ◽  
Evaporation Rate ◽  
Ambient Pressure ◽  
Silicon Crystals ◽  
Silicon Melt ◽  
Sb Doping ◽  
Gas Phase Transport ◽  
Phase Transport

AbstractIn Czochralski-grown (CZ) silicon single crystals, antimony (Sb) doping decreases the oxygen concentration by enhancing oxygen evaporation from the melt surface. In this study, Ar ambient pressures of around 100 Torr over the silicon melt were found to suppress evaporation of oxide species. To clarify the effect of the growth chamber ambient pressure on oxygen concentration, heavily Sb-doped CZ silicon crystals were grown under Ar pressures of 30, 60, and 100 Torr. Increasing Ar pressure increases the oxygen and Sb concentrations at the melt surface. The oxygen concentration under an Ar pressure of 100 Torr was 1.2 times higher that under 30 Torr when the solidified fractions are 0.5 or larger. The oxygen evaporation rate is controllable by gas phase transport of Sb2O at high Ar pressures.

Effect of Withdrawal Rate on Defects of Upgraded Metallurgical Grade (UMG)-Silicon Prepared by Vacuum Directional Solidification

2013 ◽  
Vol 750 ◽  
pp. 316-319
Author(s):  
Wen Hui Ma ◽  
Yong Jiang ◽  
Yang Zhou ◽  
Kui Xian Wei ◽  
Bin Yang ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Directional Solidification ◽  
Carbon Concentration ◽  
Withdrawal Rate ◽  
Structural Defects ◽  
Driving Mechanism ◽  
Quasi Equilibrium ◽  
Metallurgical Grade Silicon ◽  
Grade Silicon ◽  
Upgraded Metallurgical Grade Silicon

The structural defects including dislocations and grain boundaries (GBs) in upgraded metallurgical grade silicon (UMG-Si) prepared by vacuum directional solidification were investigated. The results demonstrated that higher withdrawal rates increased the dislocation density. The state of melt growth changed from quasi-equilibrium to non-equilibrium, and the GB type was also highly related to the withdrawal rate, especially for ∑3 boundary. The change of total interfacial energy and increase of carbon concentration may be a possible driving mechanism for this phenomenon.

Dislocations and Plasticity in Silicon Crystals by 3-D Mesoscopic Simulations

1998 ◽  
Vol 538 ◽  
Author(s):  
L.P. Kubin ◽  
A. Moulin ◽  
P. Pirouz
Keyword(s):  
Dislocation Density ◽  
Yield Stress ◽  
Low Temperatures ◽  
Mechanical Twinning ◽  
Mesoscopic Simulation ◽  
Brittle To Ductile Transition ◽  
Silicon Crystals ◽  
Partial Dislocations ◽  
Yield Point Phenomenon ◽  
Dislocation Sources

AbstractSeveral problems related to the dynamics of dislocation sources and the plasticity of silicon crystals are investigated with the help of a mesoscopic simulation. The questions successively examined are the dynamics of a source of perfect dislocations and the conditions under which perfect or partial dislocations are emitted by a source. This leads to a discussion of the initial steps of the model proposed by Pirouz for mechanical twinning and, further, to the suggestion that a relation may exist between several transitions experimentally observed at low temperatures in elemental or compound semi-conductors: a change in the slope of the yield stress vs. temperature curves, a brittle-to-ductile transition and a change in the nature of the mobile dislocations. Finally, simulations are presented of the yield point phenomenon that is a well-known feature of Si and Ge crystals. The results are discussed in terms of evolutionary laws for the total dislocation density during straining.

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