Single Crystal Substrates

Single Crystal Substrates List

Single crystal substrates are widely used in epitaxy technology. The quality of single crystal substrates greatly influences the performances of the products that grow on the surface. One important application of epitaxy technology is to produce film, and any minor defects of the single crystal substrates will destroy the quality of the film grown on the substrate surface. Therefore, the surface quality of the single crystal substrates is critical for epitaxy technology. Moreover, with the development and improvement of epitaxial thin film growth technology, more and more high requirements have been put forward for single crystal substrates.

Figure 1. An example of epitaxy technology process.

Applications:

• LED lighting field: LED lighting technology is one of the most promising high-tech fields in the 21st century. Due to the advantages of small size, low power consumption, long service life, high brightness, low heat, green environmental protection, strong and durable, LED lighting has been recognized by countries around the world. The core of LED lighting technology is light emitting diode (LED), and the single crystal substrates are the key to prepare this device. Single crystal substrates used in this field mainly include sapphire (Al₂O₃) and silicon carbide (SiC) substrates.
• Solar cell field: The development and utilization of solar energy provides an effective way to solve the shortage and pollution of conventional energy. Based on photovoltaic effect, solar cell can convert light energy into electric energy. In the composition of solar cells, single crystal substrates are essential and play important roles in the performances.
• Superconductivity field: Some single crystal substrates have the properties of superconductivity under certain conditions and have important applications in the field of superconductivity. For example, MgO single crystal substrate has good chemical stability, thermal conductivity and insulation at high temperature, and has very small dielectric constant and loss at high frequency. It is an important high temperature superconducting thin film single crystal substrate.
• Scientific research field: In the field of scientific research, single crystal substrates also are widely applied. For example, using the excellent optical and mechanical properties, sapphire single crystal substrates can be used to make various specifications of optical devices for experimental use and to make windows of devices working in abnormal environments.
• The others: Single crystal substrates are also widely used in other fields including mobile phone industry, medical field and the others.

Classification:

• SiC single crystal substrates: SiC single crystal substrates are covalent compounds. SiC single crystal substrates have stable chemical properties and does not react with any substance at room temperature. SiC single crystal substrates have the advantages of small thermal expansion coefficient, high hardness, good strength, stable performance under high temperature and high pressure, long service life and the others, which can be used in radioactive, corrosive, high temperature and pressure working conditions.

Figure 2. The crystal structure of SiC.

• Sapphire single crystal substrates: Sapphire single crystal substrates formed by the crystallization of alumina, is a typical hard and brittle material with good mechanical properties, thermal stability, chemical stability and radiation resistance. Sapphire has a very good performance in all aspects, and has an incomparable comprehensive performance compared with other materials.
• The others: With the development of technology, many other single crystal substrates are reported including MgO single crystal substrates and the others. MgO single crystal substrates is a face-centered cubic crystal, which is a solid insulating inorganic material with a NaCl crystal structure.

References

1. Gronheid R, Singh A, Younkin T R, et al. Rectification of EUV-patterned contact holes using directed self-assembly[C]. Spie Advanced Lithography. 2013.
2. Saeid M, Saeed K, Seyed E H. Enhanced Characteristics of Square-Shaped Extended Source TFET Via Silicon Carbide Polytype (3C-Sic) and A Dopant Pocket Layer[J]. Oriental Journal of Chemistry, 2017.