A METHOD FOR PRODUCTION OF INITIAL POLYCRYSTALLINE SILICON IN THE FORM OF WIDE PLATES WITH LOW BACKGROUND IMPURITY CONCENTRATION Russian patent published in 2004 - IPC

FIELD: production of semi-conductive materials. SUBSTANCE: the invention presents a method for production of semi- conductive materials and may be used for production of initial polycrystalline silicon by settling on the heated substrates (bases) in the process of hydrogenous reduction of chlorosilanes or from the gas phase of monosilane. The method includes location in the reactor of a chemically inert to the vapor or the vapor- gas mixture flat substrate with the specific resistance in the interval from 1•10^-3 to 50.0 Ohm cm, feeding of a vapor of monosilane or a vapor-gas mixture of silane with hydrogen along the surface of the flat substrate, heating of the substrate by the running electric current, settling silicon on it, removal of the flat substrate with deposited silicon from the reactor and cutting silicon off from it with preservation of the deposited layer of no less 2 mm thick, clearing the surface of the cut by grinding, etching and cleansing in the deionized water. To decrease the uncontrolled pollution of produced material the flat substrates are preliminary treated for one hour under the temperature of 1200 - 1400 C and then they are deposited by a layer of silicon of no less than 0.1 cm thick recovered from trichlorosilane by hydrogen. After that the end sections of the substrates with open surfaces are coated with silver or copper. Besides, as the flat substrates it is possible to use the clean plates and strips of silicon cut off after deposition, etching and cleansing or the flat substrates slit along a conducting initial substrate after silicon deposition and cleaning by grinding, etching and cleansing. EFFECT: the invention allows to increase quality of the produced material at preservation of high productivity of the process. 5 cl, 4 dwg, 2 ex