Optimization of pulling speed for decreasing thermal stress in different quartz crucible size with Czochralski method

2015 ◽  
Author(s):  
Kwanghun Kim ◽  
Sungsun Baik
Keyword(s):  
Thermal Stress ◽  
Czochralski Method ◽  
Quartz Crucible

scholarly journals Control of Thermophysical Properties of Langasite-Type La3Ta0.5Ga5.5O14 Crystals for Pressure Sensors

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 936
Author(s):  
Haruki Usui ◽  
Makoto Tokuda ◽  
Kazumasa Sugiyama ◽  
Takuya Hoshina ◽  
Takaaki Tsurumi ◽  
...  
Keyword(s):  
Thermal Stress ◽  
High Temperatures ◽  
Thermal Stresses ◽  
Pressure Sensors ◽  
Czochralski Method ◽  
Order Type ◽  
Cation Site ◽  
Young’S Moduli ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

We present a possible method to reduce the anisotropy of the thermal stress generated on langasite-type La3Ta0.5Ga5.5O14 (LTG) piezoelectric crystals arising from the mismatch of the thermal expansion coefficients and Young’s moduli of the crystals and metals at high temperatures. To formulate this method, the thermal stresses of order-type langasite crystals, in which each cation site is occupied by one element only, were calculated and compared to each other. Our results suggest that the largest cation site affects the thermal stress. We attempted to replace La3+ in LTG by a larger ion and considered Sr2+. Single crystals of strontium-substituted LTG (Sr-LTG) were grown using the Czochralski method. The thermal stress along the crystallographic c-axis decreased but that perpendicular to the c-axis increased by strontium substitution into the LTG crystal. The anisotropic thermal stress was reduced effectively. The Sr-LTG single crystal is a superior candidate material for pressure sensors usable at high temperatures.

Numerical Analysis on Cooling Process of Monocrystal Silicon Rod Manufactured with Czochralski Method

2012 ◽  
Vol 217-219 ◽  
pp. 1425-1428 ◽  
Author(s):  
Xiao Xia Liu ◽  
Li Jun He ◽  
Rui Zhou ◽  
Shao Lin Ma ◽  
Jing Mao
Keyword(s):  
Residual Stress ◽  
Thermal Stress ◽  
Numerical Analysis ◽  
Czochralski Method ◽  
Temperature Fields ◽  
Stress Fields ◽  
Finite Element Code ◽  
Cooling Process ◽  
Thermally Induced ◽  
Thermal Stress Field

A numerical analysis was performed to investigate the temperature distribution and thermal stress field in monocrystal silicon rod in the cooling process of manufactured with Czochralski (CZ) method. The thermally-induced residual stress fields of silicon rod under different length of cool-down time conditions were obtained as well as temperature fields, respectively. All simulations were finished by using ANSYS finite element code. It showed that, maximum thermal stress was mainly appeared on rod surface, the influence of length of cool-down time on it was not remarkable, the magnitude of it was far below the critical strength of silicon throughout.

Σ =13 tilt grain boundary in silicon bicrystal

1990 ◽  
Vol 48 (4) ◽  
pp. 562-563
Author(s):  
M.J. Kim ◽  
Y.L. Chen ◽  
R.W. Carpenter ◽  
J.C. Barry ◽  
G.H. Schwuttke
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Rotation Axis ◽  
Czochralski Method ◽  
High Resolution Electron Microscopy ◽  
Image Simulation ◽  
Simulation Techniques ◽  
Resolution Electron ◽  
The Common ◽  
Tilt Grain Boundary

The structure of grain boundaries (GBs) in metals, semiconductors and ceramics is of considerable interest because of their influence on physical properties. Progress in understanding the structure of grain boundaries at the atomic level has been made by high resolution electron microscopy (HREM) . In the present study, a Σ=13, (510) <001>-tilt grain boundary in silicon was characterized by HREM in conjunction with digital image processing and computer image simulation techniques.The bicrystals were grown from the melt by the Czochralski method, using preoriented seeds. Specimens for TEM observations were cut from the bicrystals perpendicular to the common rotation axis of pure tilt grain boundary, and were mechanically dimpled and then ion-milled to electron transparency. The degree of misorientation between the common <001> axis of the bicrystal was measured by CBED in a Philips EM 400ST/FEG: it was found to be less than 1 mrad. HREM was performed at 200 kV in an ISI-002B and at 400 kv in a JEM-4000EX.

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