Fabrication of nanocrystalline silicon layers by plasma enhanced chemical vapor deposition from silicon tetrafluoride

Semiconductors - The data on fabrication of silicon layers on various substrates by plasma enhanced chemical vapor deposition from the (silicon tetrafluoride)-hydrogen system are reported. The...     

Thermochemical purification of sulfur from hydrocarbons

The behavior of carboniferous impurities during thermochemical purification of sulfur was studied. The integral absorption coefficient for the IR absorption band at 2920 cm^-1, related to aliphatic hydrocarbons, was determined. The detection limit for aliphatic hydrocarbons in sulfur was evaluated to be 2 x 10^-5 wt % (3σ criterion).     

Experimental investigations of silicon tetrafluoride decomposition in ECR discharge plasma

The results of first experiments on the investigation of plasma of electron cyclotron resonance (ECR) discharge, sustained by CW radiation of technological gyrotron with frequency 24 GHz are considered. The parameters of nitrogen plasma of ECR discharge in magnetic field up to 1 T were investigated by Langmuir probe in the pressure range 10(-4)-10(-2) mbar under different values of microwave power. Depending on gas pressure and power of microwave radiation, the typical temperature and density of electrons could attain values of 1-5 eV and 10(11)-10(12) cm(-3), respectively. The prospects for using of ECR discharge for plasma chemical decomposition of silicon tetrafluoride (SiF(4)) have been experimentally demonstrated. Plasma was created from SiF(4) and hydrogen (H(2)) gas mixture and heated by microwave radiation in ECR conditions. Using the method of mass-spectrometry analysis of the gas at the outlet from the reactor and the weighting method, the content of the resultants of SiF(4) decomposition as a function of process parameters was investigated. It was shown that SiF(4) decomposition degree strongly depends on the microwave power, gas pressure in the reactor, gas flow rates, and can attain the value of 50%. The possible applications of PECVD method based on ECR discharge for production of isotopically pure elements with high deposition rate are discussed.     

Use of spectral methods of analysis and evaluation of the biological action of industrial pollution

Translated from Izmeritel'naya Tekhnika, No. 3, pp. 61–62, March, 1992.     

Behavior of Lithium Donors in Bulk Single-Crystal Isotopically Pure 28Si1 –x72Gex Alloys

Semiconductors - The behavior of lithium donors in bulk single-crystal isotopically pure Si1 – xGex alloys (x = 0.0039–0.05) enriched in spinless 28Si and 72Ge isotopes (99.998 and...     

Developing the production of high-alumina mortar

The St. Petersburg Institute of Refractories has developed a technology for manufacturing a high-alumina mortar of grade MMK85 used for binding high-alumina and corundum refractories. The mortar has been tested under laboratory conditions and shipped to the Volzhsk Pipe Plant for use in equipment of the electrometallurgical complex. Translated from Ogneupory i Tekhnicheskaya Keramika, No. 3, pp. 30–31, March, 1998.