1991 Fiscal Year Final Research Report Summary
Estimation of Thermal Stress During Growth Process of Bulk Single Crystals used in Electronic Devices
| Project/Area Number |
02650074
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
材料力学
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| Research Institution | Kyushu University |
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Principal Investigator |
MIYAZAKI Noriyuki Kyushu University, Department of Chemical Engineering, Associate Professor, 工学部, 助教授 (10166150)
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| Co-Investigator(Kenkyū-buntansha) |
MUNAKATA Tsuyoshi Kyushu University, Department of Chemical Engineering, Professor, 工学部, 教授 (00037714)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Single Crystal / Czochralski Growth / Thermal Stress / Elastic Constants / Anisotropy / Finite Element Method / Dislocation |
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| Research Abstract |
Thermal stress analyses of Si, GaAs and InP bulk single crystals during Czochralski growth were performed in the cases of the[001] and[111] pulling directions by using a three-dimensional finite element program. Elastic anisotropy was taken into account in this program. The stress components obtained from the thermal stress analysis were converted into the parameter sigma_<tot> representing the effective stress for glide strains. The values and distribution patterns of sigma_<tot> were compared between the anisotropic analysis and the isotropic analysis using the Young's modulus and the Poisson's ratio in the (111) plane. The following were obtained. (1) In the case of the[001] pulling direction, the isotropic analysis provides larger sigma_<tot> values than the anisotropic analysis. (2) In the case of the[1111 pulling direction, the difference between the results obtained from both analyses consists in the distribution patterns of sigma_<tot> rather than in its values.
Thermal stress a
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nalyses of silicon bulk single crystals with 6 or 8 inches were performed in the cases of the[001] and[111] pulling directions by using the above-mentioned finite element program developed for calculating thermal stress in a bulk single crystal during Czochralski growth. The temperature distribution and shape of a bulk single crystal which were required for the thermal stress analysis were obtained from a computer program for a transient heat conduction analysis. The stress components obtained from the thermal stress analysis was converted into the parameters related with dislocation density. The following were obtained. (1) The dislocation density parameters show the maximum value at the center of the bottom or the side wall near the solid-melt interface. (2) The values of the dislocation density parameters correlate with the shape of the solid-melt interface. (3) The values of the dislocation density parameters are smaller in the case of the[111] pulling direction than in the case of[001] pulling direction. Less
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