Applications of Quartz Glass in Semiconductor Industry
In consequence of the accelerated global development of information technology, networking and knowledge-based economy, the semiconductor integrated circuit industry is acquiring greater importance, and it has become a basic and strategic industry related to the national economy, national defense construction, people’s life and information security. Quartz glass, in particular, has become a crucial material in the manufacture of IC chips due to its exceptional characteristics, including high purity, high temperature resistance, and low thermal expansion.
At present, the annual output of silicon single crystal is more than 2000t, and the quartz crucible employed in the pulling process of silicon single crystal is a transparent or translucent crucible made of high-purity quartz powder, with the method of gas refining or arc melting. The SiO2 content varies greatly according to the application of single crystalline silicon, typically exceeding 99.99%. The future development of this material is to increase its dimensions, purity, and deformation resistance under high temperature.
The quartz boat is an essential apparatus for the diffusion, oxidation, chemical vapour deposition (CVD) deposition and annealing treatment of single crystalline silicon wafers. The current quartz boat is available in a variety of specifications and sizes, depending on the production size and treatment process of the single crystalline silicon wafer. Consequently, there is no fixed specification or form of the quartz boat. In general, the boats are available in two forms, horizontal and vertical, and are manufactured from quartz or SiC materials.
A holder is positioned in front of the diffusion furnace tube of single crystalline silicon, serving as a carrier for the quartz boat as it is transported into the furnace and subsequently removed. The holder supports several quartz boats, each containing single crystalline silicon wafers, and facilitates their transfer into the diffusion furnace for the diffusion, oxidation and annealing process.
Because the holder and quartz boat are in direct contact with the single crystalline silicon wafers and are used at high temperatures, there is a significant requirement for the purity, temperature resistance and dimensional accuracy of the quartz glass.
The quartz glass bell jars are mainly used for the reduction of polysilicon, and some high-purity quartz bell jar is also used in the extended bell jar of single crystalline silicon. Wafer extending is one of the key processes in the production of semiconductor devices and integrated circuits. At present, applied extended furnaces are generally vertical, and the furnace body is a large-diameter translucent quartz glass bell with flange. The size of the bell jar depends on the size of the extended furnace and the silicon wafer to be extended.
A quartz glass flange is a quartz glassware that is used in conjunction with quartz glass diffusion tube in the diffusion, oxidation, and CVD deposition furnace of single crystalline silicon. Its primary function is to serve as a connecting element and its size depends on the size of the diffusion tube. In the context of quartz glass applications, the purity, temperature resistance, and dimensional accuracy of the material are of paramount importance.
As China gradually becomes the world’s largest production base in the fields of optical communication equipment, program switches, mobile phones, microcomputers and household appliances, China will become the world’s second largest consumer of integrated circuits in the next few years. At the same time, there is a clear market demand for the key materials, special equipment, components, etc., which has promoted the accelerated growth of related industries, and quartz glass manufacturing industry will undoubtedly benefit from the development of electronic information, semiconductors, and integrated circuits industries.
