HIGH-PURITY GERMANIUM HYDRIDE PREPARATION METHOD Russian patent published in 2004 - IPC

FIELD: industrial inorganic synthesis.

SUBSTANCE: invention relates to developing electrochemical method for preparation of high-purity germanium hydride appropriate for use as germanium source in microelectronics. Germanium hydride is prepared by electrolysis of water-alkali solution containing germanium dioxide in concentration from at least 40 g/l to solubility limit, said electrolysis being effected on nickel cathode in diaphragm electrolyzer at current density 1.0-1.5 A/cm² and temperature no higher than 65^оС. In particular, electric current is passed through water-alkali solution over a period of time required for achieving minimum allowable limit of impurities. Electrolysis is effected by cross-mixing of electrolyte streams, wherein electrolyte stream from cathode space is supplied into anode space after separation of germanium hydride and hydrogen and electrolyte streams from anode space into cathode space after separating oxygen. Synthesized germanium hydride is then isolated from its mixture with hydrogen. Isolated germanium hydride is further purified using membrane technique to achieve summary level of impurities (SiH₄, AsH₃, PH₃, H₂S, CH₄, Fe, Ni, Al, Ca, Mg, etc.) does not exceed 1·10^-6 to 1·10^-7%, which is acceptable for rather wide application areas. Use of membrane technique offers an way for freeing germanium hydride of suspended particles 0.05 mcm in size to level below 5.5·10^-3 particles/mole, which makes product acceptable for such areas as optics and laser engineering. Productivity of method is 40-50 g/h.

EFFECT: enhanced germanium hydride purification efficiency.

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