Silicon carbide (SiC), as a kind of wide band gap semiconductor material, plays an increasingly important role in the application of modern science and technology. Silicon carbide has excellent thermal stability, high electric field tolerance, intentional conductivity and other excellent physical and optical properties, and is widely used in optoelectronic devices and solar devices. Due to the increasing demand for more efficient and stable electronic devices, mastering the growth technology of silicon carbide has become a hot spot.
So how much do you know about SiC growth process?
Today we will discuss three main techniques for the growth of silicon carbide single crystals: physical vapor transport (PVT), liquid phase epitaxy (LPE), and high temperature chemical vapor deposition (HT-CVD).
Physical Vapor Transfer Method (PVT)
Physical vapor transfer method is one of the most commonly used silicon carbide growth processes. The growth of single crystal silicon carbide is mainly dependent on sublimation of sic powder and redeposition on seed crystal under high temperature conditions. In a closed graphite crucible, the silicon carbide powder is heated to high temperature, through the control of temperature gradient, the silicon carbide steam condenses on the surface of the seed crystal, and gradually grows a large size single crystal.
The vast majority of the monocrystalline SiC we currently provide are made in this way of growth. It is also the mainstream way in the industry.
Liquid phase epitaxy (LPE)
Silicon carbide crystals are prepared by liquid phase epitaxy through a crystal growth process at the solid-liquid interface. In this method, the silicon carbide powder is dissolved in a silicon-carbon solution at high temperature, and then the temperature is lowered so that the silicon carbide is precipitated from the solution and grows on the seed crystals. The main advantage of the LPE method is the ability to obtain high-quality crystals at a lower growth temperature, the cost is relatively low, and it is suitable for large-scale production.
High temperature Chemical Vapor Deposition (HT-CVD)
By introducing the gas containing silicon and carbon into the reaction chamber at high temperature, the single crystal layer of silicon carbide is deposited directly on the surface of the seed crystal through chemical reaction. The advantage of this method is that the flow rate and reaction conditions of the gas can be precisely controlled, so as to obtain a silicon carbide crystal with high purity and few defects. The HT-CVD process can produce silicon carbide crystals with excellent properties, which is particularly valuable for applications where extremely high quality materials are required.
The growth process of silicon carbide is the cornerstone of its application and development. Through continuous technological innovation and optimization, these three growth methods play their respective roles to meet the needs of different occasions, ensuring the important position of silicon carbide. With the deepening of research and technological progress, the growth process of silicon carbide materials will continue to be optimized, and the performance of electronic devices will be further improved.
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Post time: Jun-23-2024