Growth silicon nitrides

Ohji T (1994) Tensile Creep Rupture And Subcritical Crack Growth of Silicon Nitride. In Hoffmann MJ, Petzow G (eds) Tailoring of Mechanical Properties of Si3N4 Ceramics. Kluwer Academic Publishers, Netherlands, p 339... 

Emoto, H. and Mitomo, M. Control and characterization of abnormal growth grains in silicon nitride ceramics , J. Eur. Ceram. Soc., 17 (1997) 797-804. 

Microstructures of the two GPS-ed silicon nitride materials (a) SN-F (not seeded, cold pressed), (b) SN-C (seeded, tape cast). Plasma etching highlights the epitaxial growth of P-sialon on P-Si3N4 cores (indicated by the arrows). 

This approach was successfully used in modeling the CVD of silicon nitride (Si3N4) films [18, 19, 22, 23]. Alternatively, molecular dynamics (MD) simulations can be used instead of or in combination with the MC approach to simulate kinetic steps of film evolution during the growth process (see, for example, a study of Zr02 deposition on the Si(100) surface [24]). Finally, the results of these simulations (overall reaction constants and film characteristics) can be used in the subsequent reactor modeling and the detailed calculations of film structure and properties, including defects and impurities. 

PECVD silicon nitride films are amorphous at the temperature used for growth, so film structure (i.e., grain size) is not an issue. The film quality is determined by ... 

It is not always possible to obtain a low-porosity body by pressureless sintering , i.e. by sintering at atmospheric pressure. For example, difficulties are experienced with silicon nitride and silicon carbide. More commonly it may prove difficult to combine the complete elimination of porosity with the maintenance of small crystal size. These problems can usually by overcome by hot-pressing, i.e. sintering under pressure between punches in a die, as shown in Fig. 8.9. The pressure now provides the major part of the driving force eliminating porosity and the temperature can be kept at a level at which crystal growth is minimized. 

For 3C-SiC substrates, not nitridation but low temperature buffer layer growth without nitridation has been used as an initial process, under the apprehension that amorphous silicon nitride layers are formed... 

Penetration of both types of cavity into the silicon nitride grains, as shown in Fig. 4.14, suggests that cavity growth occurs by the diffusion of silicon nitride from the cavity surface to the grain boundary. The transition between the two types of cavity can be rationalized by the Chuang theory of cavity growth,96 which relates the mode of cavity growth to the relative diffusion rate... 

Early work (e.g., Refs. 44 and 45) on silicon nitride ceramics for a limited range of high temperature cyclic loading conditions led to the hypothesis that the mechanisms of cyclic and static fracture at elevated temperature are identical, and that the cyclic crack growth rates can be predicted on the basis of static fracture data. One of the techniques commonly used to derive cyclic crack growth rates solely on the basis of static load fracture data involves integration of the relationship in Eqn. (13) over the duration of the fatigue cycle such that... 

U. Ramamurty, T. Hansson, and S. Suresh, High-Temperature Crack Growth in Monolithic and SiCVReinforced Silicon Nitride Under Static and Cyclic Loads, J. Am. Ceram. Soc., 77[11], 2985-2999 (1994). 

See, e.g., Aoki, T. Ogishima, T. Wrobel, A. M. Nakanishi, Y. Hatanaka, Y. Silicon nitride film growth by remote plasma CVD using tris(dimethylamino)silane. Vacuum 51 (1998) 747-750. 

K. R. Lai and T. Y. Tien, Kinetics of j3-Si3N4 grain growth in silicon nitride ceramics sintered under high nitrogen pressure. J. Am. Ceram. Soc. (in press). 

The formation of silicon nitride whiskers was observed in several different reactions, including vapor deposition, CVD, and growth from a melt. However, only the following techniques are considered to have commercial significance nitriding of metallic silicon or silicon-silica mixture, carbothermal reduction of silica with simultaneous nitridation, and thermal decomposition of silicon halides. 

The a l3 Transformation and Grain Growth in Silicon Nitride Ceramics... 

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