Silicon nitride applications

Mikijelj, B., Mangels.)., Belfield, E., and MacQueen, A. (2004) Silicon nitride applications in modem diesel engines. Report Ceradyne 2004-01-1448. 

Plasma CVD was first developed in the 1960s for semiconductor applications, notably for the deposition of silicon nitride. The number and variety of applications have expanded greatly ever since and it is now a major process on par with thermal CVD. 

An RF plasma is generated at a frequency of 13.56 MHz. A typical equipment consists ofparallel electrodes as shown inFig. 5.20. It is a cold-wall design which is used extensively forthe deposition of silicon nitride and silicon dioxide for semiconductor applications. 

Silicon nitride (Si3N4) is a major industrial material which is produced extensively by CVD for electronic and stmctural applications. It is an excellent electrical insulator and diffusion barrier (to sodium and water vapor) and has replaced CVD oxides in many semiconductor... 

The market for silicon nitride is fast growing, particularly in structural and chemical resistance applications and as a thin film in semiconductor devices.P 1... 

In this particular example as in many others, a proper analysis of cost is a crucial factor. An example is the production of balls for ball bearings. Coated ball bearings (or monolithic silicon nitride) greatly outperform steel balls but their cost is considerably higher. Steel balls in passenger-automobile applications are satisfactory and normally last the life of the car and the far-longer life of the ceramic balls is not needed. 

Hussain, T., and Ibberson, V., Synthesis of Ultrafme Silicon Nitride in an RF Plasma Reactor, in Advances in Low-Temperature Plasma Chemistry, Technology, Applications, 2 71-77, (H. Boenig, ed), Technomic, Lancaster (1984)... 

Soluble polysilane polymers can also be used as precursors to silicon carbide. The first such application, using (PhMeSi)n-(Me2Si)m copolymers ("Polysilastyrene"), was to strengthen silicon nitride ceramics. The Si3N4 ceramic body was soaked in polysilane and refired, leading to the formation of silicon carbide whiskers in the pore spaces and a consequent increase in strength. (U)... 

Non-oxide ceramics such as silicon carbide (SiC), silicon nitride (SijN ), and boron nitride (BN) offer a wide variety of unique physical properties such as high hardness and high structural stability under environmental extremes, as well as varied electronic and optical properties. These advantageous properties provide the driving force for intense research efforts directed toward developing new practical applications for these materials. These efforts occur despite the considerable expense often associated with their initial preparation and subsequent transformation into finished products. 

Silicon carbide, SiC [1] and silicon nitride, Si3N4 [2], have been known for some time. Their properties, especially high thermal and chemical stability, hardness, high strength, and a variety of other properties have led to useful applications for both of these materials. 

As a second example of the application of ion-beam analysis techniques to semiconductors, we take the calibration of IR absorption measurements of the hydrogen content of sputtered amorphous silicon and silicon nitride. In early measurements, the hydrogen content of glow-discharge a-Si H deduced from IR absorption measurements, using ablsinitio calculations of the absorption cross section of the Si—H IR absorption bands, was com-... 

Mass spectrometry is also extremely useful as a process monitor. Less sophisticated residual gas analyzers (RGA) operating on the principles of mass spectrometry are available for these purposes and for end point detection. For the etching of Si 128-130), poly-Si 130), silicon nitride 130), and Si02 (729), SiF (m/e=85) has been shown to be effective for end-point detection. In addition, (m/e=14) is useful for nitride 129,130) in leak tight systems, while O (m/e =16), CO (m/e =44) and Si" " (m/e=29) are useful for oxide (757). Because of the general nature of mass spectrometry as a diagnostic tool, it should be applicable to etching studies of metals and other semiconductor materials. 

For imaging applications, minimisation of the damage to DNA molecules by the AFM tip is essential. One method of less-invasive imaging is based on phase (rather than height) imaging, which employs for instance 100 mm long silicon nitride cantilevers with narrow arms inserted into a fluid cell [65]. Alternatively, or better complementary, the operation in liquids [66], and... 

J. J. Burke, ed., Powder Metal High-Performance Applications, Proceedings of the 18th S agamore Army Material Research Conference, Syracuse University Press, Syracuse, N.Y., 1972. Review on silicon carbide—silicon nitride ceramics. 

Besides the chemical industry, silicon is used as a powder in the ceramics (qv) industry for the production of silicon carbide and silicon nitride parts (see Advanced CERAMICS). Silicon powder is also used as an explosive for defense applications and in the refractory industry for plasma spraying with other oxide mixtures (see Refractory coatings). 

The coupling of a trialkylsilane and an amine with loss of H2, catalyzed by palladium on carbon, was first reported by Sommer and Citron in 1967.178 More recent work by Laine and Blum has involved the application of catalytic dehydrocoupling of compounds containing Si-H and N-H bonds to form aligo- and polysilazanes. These polymers, with silicon-nitrogen bonds in the backbone, are useful precursors to silicon nitride. In the presence of Ru3(CO)i2, silicon-nitrogen bonds are cleaved and reformed... 

In one application (production or aluminum beverage can lids), a monolithic silicon nitride punch has demonstrated a useful life greater than ten times that of a cemented carbide tool. 

Because of the important potential applications of silicon nitride, the use of low-cost starting materials, such as elemental silicon and liquid ammonia or amines, may be more effective than the existing chloride method. In earlier work, litis process was found to form silicon di-imide (Si(NH)2), but required purification steps to remove chloride. 

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