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The crystal growth process of an InAs-GaAs binary semiconductor by the Traveling Liquidus-Zone (TLZ) method is investigated under terrestrial gravitational conditions numerically and the effect of the angle between the crystal growth direction and the gravity direction on the crystal growth process is discussed. First, this new crystal growth technique is explained and then a numerical mode and calculation method of the growth of binary crystals are developed, by which the flow field in the solution, the temperature and concentration fields in both the solution and crystals, and the shape and movement of the crystal-solution interfaces are determined. Focused is, in particular, the effect of the crystal size and the inclination angle on the crystal growth process. It is found that 1) When the crystal size is 2 mm, convection is reduced and the concentration field is not seriously deformed as long as the inclination angle is less than 1 degree. The degree of supercooling is remarkably reduced compared to the case when crystals are grown in the horizontal direction; 2) When the crystal size is greater than 5 mm, convection is intensified and the concentration field is seriously deformed. The degree of supercooling is increased as the inclination angle increases. The above results show that growing single crystals under terrestrial gravitational conditions are very difficult if the crystal size is greater than 5 mm., NASDA Technical Memorandum, 宇宙開発事業団技術報告

Two-dimensionality of a flight cartridge is numerically investigated. In order to carry out this study, newly introduced are two indices, that is, two-dimensionality and convection influence index. Although the maximum two-dimensionality increases with a sample diameter and time, the two-dimensionality at the half radius decreases with increment of the sample diameter. The convection influence index increases in small diameter region and saturates around the diameter of 10 mm. Making both indices relevant simultaneously needs further study and will be continuously investigated in the next year., NASDA Technical Memorandum, 宇宙開発事業団技術報告

Crystal growth simulations of a binary InAs-GaAs semiconductor were carried out. The following problems were investigated; 1) Development of an advanced simulation code for the analysis of the velocity, temperature, concentration fields and interfacial shapes by TLZ method and 2) Analysis of the crystal growth process under terrestrial gravity and microgravity conditions., 化合物半導体InGaAs結晶成長を行うことを想定し、TLZ法における数値シミュレーションを行い、以下の項目について解析をした。1)地上重力場での結晶成長解析(結晶径20mm)、2)微小重力場での結晶成長解析(結晶径20mm)、3)地上重力場での結晶成長解析(結晶径10mm)、4)微小重力場での結晶成長解析(結晶径10mm)。, JAXA Contract Report, 宇宙航空研究開発機構契約報告