# A Study on Heater Design for Crystal Growth of GaAs Ingot Using Growth Temperature Simulation
## 1 Introduction  
A variety of micro-LEDs have been applied to aircraft and space structures. The GaAs substrate used for micro-LEDs is one with low defect density, which has a direct effect on the performance of microelements. The development of GaAs substrates with low defect density is a very important factor. GaAs has a very high rate of defects, such as twin and poly-body defects caused by changes in the temperature gradient, growth rate, and ambient conditions. Therefore, analyzing data such as growth temperature gradient, growth rate, and environment data based on the existing accumulated technological data is necessary to improve the quality and productivity of products. A study on the application of heaters is needed to reduce occurrences of defects by analyzing these data. Due to an expansion of the micro-LED market based on various GaAs substrates, the GaAs substrate market was expected to increase from USD 160 million in 2017 to USD 428 million in 2023, and the red micro GaAs substrate market was expected to continue high growth with an annual rate of 33.6% from USD 54 million in 2017 to USD 163 million in 2023. GaAs substrates have fast electron mobility and high-frequency characteristics, so they can be used for high-speed elements and mobile and satellite communications. An analysis of their sizes shows that the 4-6 inch wafer market is in the mainstream in terms of production efficiency. Therefore, manufacturing technology optimized for 4-6 inch GaAs substrates is needed. As a result of an investigation of the previous study results related to the crystal growth of GaAs ingots, [PERSON] et al., conducted a study on gallium arsenide as a mechanical material. In this work, mechanical properties, some promising response mechanisms for micromechanical sensors, and recent micromechanical applications were reviewed for GaAs [1]. [PERSON] et al., performed a study on the variation in material parameters along the growth direction of liquid-encapsulated Czochralski-grown GaAs ingots. In this work, the variation in material properties along the growth axis of single-crystal LEC GaAs ingots was studied [2]. [PERSON] conducted research on the growth of GaAs ingots with high free electron concentrations. A horizontal gradient freeze technique was developed for the growth of GaAs ingots with high free electron concentrations while minimizing the crystal defects associated with large quantities of a dopant [3]. [PERSON] et al., carried out a study on gallium arsenide solar cells grown at rates exceeding 300 \(\upmu\)m h\({}^{-1}\) by hydride vapor phase epitaxy. The research team achieved these rates by maximizing the gallium-to-gallium monochloride conversion efficiency and by utilizing a mass-transport-limited growth regime with fast kinetics [4]. [PERSON] et al., developed and optimized the VGF-GaAs crystal growth process using data mining and machine learning techniques. In their paper, the use of various data mining and supervised machine learning techniques for optimizing VGF-GaAs growth was investigated [5]. [PERSON] et al., conducted a study on wide-bandgap perovskite/gallium arsenide tandem solar cells. This work can be an initial step in improving the usability of GaAs PV technology with enhanced performance for applications for which lightness and flexibility are required [6]. [PERSON] et al., performed research on numerical simulation of the growth of 2\({}^{\prime\prime}\) diameter GaAs crystals using the vertical gradient freeze technique. This paper presents a global two-dimensional model of a multi-zone furnace for the growth of GaAs using the bottom-seeded vertical gradient freeze (VGF) technique [7]. [PERSON] et al., carried out a study on the growth of 3\({}^{\prime\prime}\) and 4\({}^{\prime\prime}\) gallium arsenide crystals using the vertical gradient freeze (VGF) method.