Method for preparing high-purity germanium hydride

Abstract

The invention relates to the preparation of germanium-containing materials and concerns the development of an electrochemical method for preparing high-purity germanium hydride, suitable for use as a source of germanium in microelectronics technologies. Germanium hydride is prepared by electrolysis of an aqueous-alkaline solution, containing germanium dioxide in a concentration of from not less than 40 g / l to the solubility limit, at a nickel cathode in a diaphragm cell at a current density of 1.0-1.5 A / cm<2> and a temperature no higher than 65 DEG C, first passing an electrical current through the aqueous-alkaline solution for the time needed to achieve the minimum possible content of contaminants limiting for germanium hydride. The electrolysis is performed with cross-mixing of electrolyte streams, feeding a stream of electrolyte from the cathode chamber, after removal of germanium hydride and hydrogen, into the anode chamber, and a stream of electrolyte from the anode chamber, after removal of oxygen, into the cathode chamber. The germanium hydride obtained after synthesis is isolated from the mixture with hydrogen. For more thorough purification, the isolated germanium hydride is purified by the membrane method. The technical result is preparation of germanium hydride in which the total content of the contaminants SiH4, AsH3, PH3, H2S, CH4, Fe, Ni, Al, Ca, Mg, etc. is not more than 1<.>10-<6>% - 1<.>10-<7>%, which is acceptable for comparatively wide fields of practical application. The use of the membrane method ensures removal from the germanium hydride of suspended particles with a size of 0.05 m to a level of less than 5.5<.>10-<3> particles / mole, making it suitable in such fields as, for example, optics and laser engineering. The productivity of the method is 40-50 g / hour. 2 main claims, 8 dependent claims, 1 example.

Description

technical field [0001] The present invention relates to the preparation of germanium-containing materials, and also to the improvement of high-purity germanium hydride prepared by an electrochemical method suitable for being used as germanium source in microelectronic technology. Background technique [0002] At 1.0-1.5A / cm on the nickel cathode of the diaphragm battery 2 The electrolysis of an alkaline aqueous solution containing 25-35 g / l germanium dioxide at a current density of 25-35 g / l is a known method for the preparation of germanium hydride. The electrolytic reaction is to flow the supply electrolyte from the cathode chamber into the anode chamber after taking out the germanium hydride and hydrogen gas. The flow of electrolyte in the chamber is cross-mixed with the flow of electrolyte from the anode chamber into the cathode chamber after removal of oxygen (RF Patent No. 1732697 filed on 90-01-19). [0003] This method provides a low production capacity of about 10 ...

AI Technical Summary

Problems solved by technology

In the prepared germanium hydride, SiH 4 , AsH 3 、PH 3 、H 2 S, CH 4 , Fe, Ni, Al, Ca, Mg and other pollutants are not more than 1×10 -4 %, which limits the practical application of this method, especially in the production of epitaxial Si-Ge structures that need to further improve the purity of germanium hydride