Thermal Field of 6-inch Indium Phosphide Single Crystal Growth by Semi-sealed Czochralski Method

Abstract

：Indium phosphide (InP) is a kind of important compound semiconductor material. Due to its excellent performance, InP is increasingly used in high frequency electronic devices and infrared optoelectronic devices. Currently, the price of InP devices is much higher than that of GaAs devices, mainly because of the low yield of InP single crystals and the increase of epitaxy and device process cost due to the smaller wafer diameter. Increasing the diameter of InP single crystals is critical to reducing wafer and semiconductor process costs. The main difficulties in the preparation of large diameter InP single crystals are increasing the crystal yield and reducing the stress in the crystal. The vertical gradient freeze (VGF) and the Liquid Encapsulated Czochralski (LEC) methods are commonly used in the industry to prepare InP, while the VGF method has little success in preparing 6-inch InP crystals, and the crystals prepared by the LEC method tend to have higher stress and dislocation density. This work mainly demonstrates the advantages of Semi-Sealed Czochralski (SSC) method in growing large diameter compound semiconductor materials. In this article, numerical simulations were used to analyze the temperature distribution in melt, crystal, boron oxide and atmosphere in LEC and SSC method, with emphasis on the temperature field of SSC method. In the simulation results, the temperature gradient in the crystal of SSC method is 17.4 K/cm, which is significantly lower than the temperature gradient of 28.7 K/cm in the LEC method. And the the temperature of the atmosphere near the crystal shoulder in the diameter control stage of the SSC method is 504 K higher than that of the LEC method. The thermal field of SSC method was optimized according to the simulation results, and 6-inch (15.24 cm) S doped InP single crystals with low defect density and no cracks were prepared by SSC method, which confirmed that SSC method is a good method for growing large-size InP single crystals.

Indium Phosphide Single Crystal Furnace Cooling Crystallization Temperature Control Model Research

“…Indium phosphide single crystal is an important III–V compound semiconductor material, with high photoelectric conversion efficiency, good mechanical properties, and thermal conductivity. , It has wide applications in fields such as optical communication and microwave communication. The vertical gradient freeze (VGF) method is one of the mainstream methods for industrial production of InP single crystals. The principle is to adjust the power of heaters in different sections of the crystal furnace to form a temperature gradient from low to high and then slowly cool down the furnace.…”