Chinese semiconductor industry

According to China's Jiangsu Net news, CCB Xuzhou Tongshan Sub-branch has recently led the formation of a syndicate to issue a loan of 300 million yuan for the first phase of Jiangsu Pilot Semiconductor's high-end equipment R&D and production project.

It is reported that as a major project in Jiangsu Province in 2022 and the No. 1 project in Xuzhou High-tech Zone, the leading semiconductor high-end equipment R&D and production project will start construction in December 2021, with a total investment of 5.1 billion yuan, of which the first phase is about 2.863 billion yuan. The project is committed to the localization of core parts and components of semiconductor deposition and coating equipment, filling the gap in domestic semiconductor equipment in the mid-to-high-end field. After the project is put into production, it can produce 600 sets of semiconductors and other opto-mechanical equipment annually.

According to previous news, in June 2021, the semiconductor deposition and coating equipment production base project of Guangdong Leading Rare Materials Co., Ltd. was signed and landed in Xuzhou. According to the news at the time, in 2019, Pioneer Group acquired the German FHR company (the world's leading supplier of thin-film vacuum equipment manufacturing) with a total investment of 45 million euros, and planned to build a localized production base for semiconductor deposition and coating equipment. Products include: compound semiconductor thin film equipment, MEMS thin film equipment, MDS thin film production line, precision optical thin film equipment, TCO coating equipment, HIT glass coating equipment, flat panel display array coating equipment, etc.

　　The realization of nitride material epitaxy that does not depend on the substrate lattice is expected to break through the limitations of the substrate, integrate the performance advantages of wide-bandgap semiconductor materials and other semiconductor materials, and provide a new degree of freedom for device design. In 2021, the research team used graphene two-dimensional crystals as a buffer layer, and with the help of the underlying micro-nano structures such as nano-pillars, to realize the heterohetero-epitaxy of nitride quasi-single-crystal thin films on amorphous substrates. Recently, the research team has made progress in this field, using transition metal sulfides that match the nitride lattice as buffer layers, constructing artificial growth interfaces, realizing the preparation of single crystal thin films on amorphous glass wafers, and realizing ultraviolet light emission. device preparation. This work verifies the feasibility of nitride heteroisomeric single crystal epitaxy in the extreme case of amorphous substrates.
　　Edge dislocations are a representative defect type in nitride materials, and are typically an order of magnitude higher in concentration than another typical defect, screw dislocations. Edge dislocations have an important impact on the performance of nitride light-emitting and electronic devices. Due to the inherent lattice mismatch between nitrides and heterosubstrates, effective means of suppressing edge dislocations are very limited. Recently, the research team used remote epitaxy to achieve effective reduction of edge dislocations in nitride epitaxial layers, and studied the physical mechanisms of stress release and dislocation density reduction at the atomic scale. The study found that the non-polar graphene buffer layer can weaken the lattice potential field originating from the substrate, so that the crystal orientation of the epitaxial layer can be controlled while the lattice can be relatively free. As a result, the stress induced by lattice mismatch in heteroepitaxy is relieved, and the edge dislocation density in the epitaxial layer is reduced by nearly an order of magnitude. On this low-stress GaN template, the researchers successfully fabricated InGaN/GaN quantum wells with high In composition, realizing LED devices in the yellow light band.
　　Nitride materials have a high density of threading dislocations due to the limitation of growth methods. These threading dislocations can act as non-radiative recombination centers and leakage channels, which have a serious negative impact on the performance of nitride-based optoelectronic and power electronic devices. Recently, the research team used the two-dimensional graphene-assisted epitaxy method to realize the epitaxial growth of high-quality GaN films with low stress and low dislocation density, and revealed that graphene reduces the threading dislocation density in the epitaxial layer at the interface. mechanism. The study found that graphene can partially shield the potential field of the substrate. While the potential field of the substrate realizes the regulation of the interface lattice, the fluctuation of the surface potential field is weakened to a certain extent. Therefore, the epitaxial layer can release part of the stress through atomic slip, and realize the spontaneous relaxation of stress. After the introduction of graphene two-dimensional crystals, the lattice distortion caused by threading dislocations in the GaN template is recovered at the epitaxial interface, which shows that graphene blocks the upward diffusion of threading dislocations at the interface, thus obtaining a better contrast ratio than the same. Bottom homoepitaxial GaN films with lower dislocation density.