silane
Silane is a compound of silicon and hydrogen. It is a general term for a range of compounds, including methylsilane (SiH4), ethylsilane (Si2H6), and some more advanced silane compounds, generally known as SinH2n+2. Among them, methylsilane is the most common, sometimes referred to as silane for short.
Chinese name
silane
Foreign name
silane
Pass type
SinH2n+2
Discovered by the German chemist H Buff in 1857, silane remained for the next 100 years or so the subject of a handful of laboratory studies with no use. In the 1950s, the rise of semiconductor technology, people began to consider the advantages of silane, silane began to be used in the electronics industry. Into the 1980s, the application of silane changed significantly. With the emergence of a number of new technologies or the success of using silane to develop new products, the use of silane has increased dramatically. Thousands of tons of silane are processed into ultra-pure semiconductor silicon in factories each year, and hundreds of tons of gases are used to make a wide variety of new materials and devices. Considering that most devices in these applications consume only milligrams or even micrograms of gas each, and that films made of silane are on the order of micrometers thick, this is not a small amount of silane. In the 1990s, a large number of new functional devices came out, among which there have been large-scale development of ultra-high speed, ultra-large capacity computer chips, high-definition flat displays, high efficiency and low cost solar cells, high-performance ceramic engine parts, a variety of special function sensors, and more newer devices are emerging, these devices use silane.
The reason why silane is widely used in high technology and becomes more and more important is firstly related to its characteristics, but also related to the special demand of modern high technology. Through thermal decomposition or chemical reaction with other gases, can be made from silane monocrystalline silicon, polysilicon, amorphous silicon, metal silicide, silicon nitride, silicon carbide, silicon oxide and a series of silica-containing substances. The highest purity, the finest (up to atomic size) control, and the most flexible chemical reactions can be achieved with silane. Thus, various silicon-containing materials can be made into complex and fine structures according to various needs, which is the basic condition required by modern materials and devices with various special functions.
The earliest practical use of silane and the largest application is as a high purity silicon production intermediate product, commonly known as the silane process. Traditionally, the main method for producing high purity silicon has been the trichlorosilane process (Siemens process).
Another application of silane is amorphous semiconductor amorphous silicon. Compared with single crystal semiconductor materials, amorphous silicon is easy to form extremely thin (thickness of about 10nm) large-area devices. The substrate can be glass, stainless steel, or even plastic, and the surface can be flat or curved, so it can be made into a variety of devices with excellent performance.
Silane has become the most important special gas used in semiconductor microelectronics process, which is used in the preparation of various kinds of microelectronic films, including single crystal film, microcrystal, polycrystal, silicon oxide, silicon nitride, metal silicide and so on. The microelectronic applications of silane are also developing in depth: low temperature epitaxy, selective epitaxy, heteroepitaxy. Not only for silicon devices and silicon integrated circuits, but also for compound semiconductor devices (gallium arsenide, silicon carbide, etc.). It is also used in the preparation of superlattice quantum well materials. It can be said that almost all modern advanced integrated circuit production lines need to use silane. The purity of silane has great influence on device performance and yield. More advanced devices require higher purity silanes (including ethyl silane and propanilane).
The application of silane as silicon-containing films and coatings has been extended from the traditional microelectronics industry to various fields such as steel, machinery, chemicals and optics. Silicon-containing coating can make the high temperature oxidation resistance of ordinary steel increased to more than 100,000 times, can also make other metal high temperature chemical stability greatly improved, the corrosion resistance of the internal combustion engine blade significantly enhanced, the bonding strength between various materials and parts greatly increased, prolong the life of automobile engine parts, also can change the reflection and transmission performance of glass, Thus, significant energy saving and decorative effects are obtained. In the float glass production process with silane on the surface of the glass coated with a reflective layer of strong adhesion in the long-term sunlight does not fade, transmittance is only 1/3 of ordinary glass; The high efficiency of large area polysilicon cell (BSNSC) coated with silicon nitride has reached 15.7%. The application of silane vapor deposition to produce various silicon-containing films in high technology is increasing.
Another potential application of silane is the manufacture of high performance ceramic engine parts, especially the use of silane to produce silicide (Si3N4, SiC, etc.) micropowder technology is getting more and more attention. The United States, Japan and other countries are spending hundreds of millions of dollars to develop silicon, silicon nitride and silicon carbide powder to make high temperature resistant, high strength, high chemical stability ceramics. The micropowders prepared by the method of silane gas reaction have the highest purity, fine and even particle size, which can greatly improve the performance of ceramic parts. Its application field is very wide, such as automobile engine valve and turbocharger rotor has been practical, high-speed bearings and high performance tool has been commercialized, used for internal combustion engine can make the working temperature up to 1400℃, greatly improve the efficiency of the heat engine, suitable for a variety of fuels, prolong the service life, in addition, can also be used as a rocket insulation tile and stealth protection layer.