scholarly journals Modelling InSb Czochralski Growth

2021 ◽  
Author(s):  
Sean Bohun
Keyword(s):  
Thermal Stress ◽  
Crystal Growth ◽  
Temperature Distribution ◽  
Stefan Problem ◽  
Czochralski Growth ◽  
Experimental Setting

A model of Czrochralski crystal growth is presented that reduces the issue of finding the temperature distribution as a Stefan problem. From the temperature distribution the corresponding distribution of thermal stress inside the growing crystal can be computed. This work will allow the rapid simulation of a variety of crystal growing strategies which would be prohibitively expensive in an experimental setting.

Growth Kinetics and Thermal Stress in AlN Bulk Crystal Growth

2002 ◽  
Author(s):  
Bei Wu ◽  
Ronghui Ma ◽  
Hui Zhang ◽  
Michael Dudley ◽  
Raoul Schlesser ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Crystal Growth ◽  
Temperature Distribution ◽  
Stress Level ◽  
Grown Crystal ◽  
Power Level ◽  
Chemical Species ◽  
Group Iii Nitrides ◽  
Minor Effect ◽  
Group Iii

Group III nitrides, such as GaN, AlN and InGaN, have attracted a lot of attention due to the development of blue-green and ultraviolet light emitting diodes (LEDs) and lasers. In this paper, an integrated model has developed based on the conservation of momentum, mass, chemical species and energy together with necessary boundary conditions that account for heterogeneous chemical reactions both at the source and seed surfaces. The simulation results have been compared with temperature measurements for different power levels and flow rates in a reactor specially designed for nitride crystal growth at NCSU. It is evident that the heat power level affects the entire temperature distribution greatly while the flow rate has minor effect on the temperature distribution. The results also show that the overall thermal stress level is higher than the critical resolved shear stress, which means thermal elastic stress can be a major source of dislocation density in the as-grown crystal. The stress level is strongly dependent on the temperature gradient in the as-grown crystal. Results are correlated well with defects showing in an X-ray topograph for the AlN wafer.

Analysis to Reduce Thermal Stress in Oxide Single Crystal During Czochralski Growth

2004 ◽  
Author(s):  
Shigeki Hirasawa ◽  
Hiroyuki Ishibashi ◽  
Kazuhisa Kurashige ◽  
Akihiro Gunji
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Temperature Distribution ◽  
Thermal Radiation ◽  
Single Crystal ◽  
Radiation Heat Transfer ◽  
Heat Transfer Analysis ◽  
Czochralski Growth ◽  
Radiation Heat ◽  
Radial Temperature

Temperature distributions and thermal stress distributions in a semi-transparent GSO crystal during Czochralski (CZ) single crystal growth were numerically investigated by thermal radiation heat transfer analysis and anisotropy stress analysis. As GSO has special optical properties, such as semi-transparency at a wavelength shorter than 4.5 μm, thermal radiation heat transfer was calculated by the Monte Carlo method. These calculations showed that thermal stress is caused by the radial temperature distribution on the outside of the upper part of the crystal. To reduce this temperature distribution, the following three manufacturing conditions were found to be effective: use a sharp taper angle of the crystal, install a lid to the top of the insulator, and install a ring around the tapered part of the crystal.

Investigation Into Thermal Stress Characteristics of Pipe-in-Pipe Under High Temperature Condition

2018 ◽  
Author(s):  
Si-Hwa Jeong ◽  
Min-Gu Won ◽  
Nam-Su Huh ◽  
Yun-Jae Kim ◽  
Young-Jin Oh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
High Temperature ◽  
Temperature Distribution ◽  
Heat Transfer Analysis ◽  
Piping System ◽  
Curved Pipe ◽  
High Temperature Condition ◽  
Single Pipe ◽  
Radiation Conditions

In this paper, the thermal stress characteristics of the pipe-in-pipe (PIP) system under high temperature condition are analyzed. The PIP is a type of pipe applied in sodium-cooled faster reactor (SFR) and has a different geometry from a single pipe. In particular, under the high temperature condition of the SFR, the high thermal stress is generated due to the temperature gradient occurring between the inner pipe and outer pipe. To investigate the thermal stress characteristics, three cases are considered according to geometry of the support. The fully constrained support and intermediate support are considered for case 1 and 2, respectively. For case 3, both supports are applied to the actual curved pipe. The finite element (FE) analyses are performed in two steps for each case. Firstly, the heat transfer analysis is carried out considering the thermal conduction, convection and radiation conditions. From the heat transfer analysis, the temperature distribution results in the piping system are obtained. Secondly, the structural analysis is performed considering the temperature distribution results and boundary conditions. Finally, the effects of the geometric characteristics on the thermal stress in the PIP system are analyzed.

Effect of the pulling, crystal and crucible rotation rate on the thermal stress and the melt–crystal interface in the Czochralski growth of germanium crystals

CrystEngComm ◽  
2021 ◽  
Vol 23 (39) ◽  
pp. 6967-6976
Author(s):  
Mahboobeh Saadatirad ◽  
Mohammad Hossein Tavakoli ◽  
Hossein Khodamoradi ◽  
Seyedeh Razieh Masharian
Keyword(s):  
Thermal Stress ◽  
Rotation Rate ◽  
Czochralski Growth ◽  
Interface Shape ◽  
Crucible Rotation ◽  
Crystal Interface

The effect of the pulling rate on the melt–crystal interface shape and melt streamline is investigated.

Thermal stress inhibition in double crucible Czochralski large diameter crystal growth

2005 ◽  
Vol 274 (1-2) ◽  
pp. 307-316 ◽  
Author(s):  
O.A. Louchev ◽  
S. Kumaragurubaran ◽  
S. Takekawa ◽  
K. Kitamura
Keyword(s):  
Thermal Stress ◽  
Crystal Growth ◽  
Large Diameter ◽  
Double Crucible

scholarly journals Homogenization of Radial Temperature by a Tungsten Sink in Sublimation Growth of 45 mm AlN Single Crystal

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5553
Author(s):  
Yue Yu ◽  
Botao Liu ◽  
Xia Tang ◽  
Sheng Liu ◽  
Bing Gao
Keyword(s):  
Thermal Stress ◽  
Crystal Growth ◽  
Heat Exchange ◽  
Single Crystal ◽  
Numerical Experiments ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Large Size ◽  
Sublimation Growth

To reduce the thermal stress during the sublimation growth of 45 mm AlN single crystal, a tungsten sink was put on the top of the crucible lid. Numerical experiments showed that the radial temperature gradient was reduced due to the homogenization effect on temperature as a result of the sink. Therefore, this simple tungsten sink method has the potential to grow large-size AlN ingots with fewer cracks. It also reveals that enhancing the heat exchange of the crucible lid is an effective way to improve the quality of crystal growth.

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