METHOD OF PRODUCTION OF MONOSILANE AND DISILANE Russian patent published in 2000 - IPC

FIELD: production of polycrystalline silicon and semiconductor structures by gas epitaxy methods. SUBSTANCE: monosilane and disilane are produced due to interaction of magnesium with mineral acid in helium atmosphere. Products thus obtained are subjected to cleaning and separation. Fluosilicic acid is used as mineral acid. Concentration of acid ranges from 5 to 39%. Process is conducted at temperature of from 40 to 57 C. Fluosilicic acid is preliminarily treated with helium during 40 to 60 minutes at temperature of from 15 to 40 C. Silanes are cleaned from dropping liquid in water cooler at temperature of from 10 to 12 C. Cleaning from polysilanes and higher silanes is effected at temperature of from minus 76 to minus 80 C. Cleaning from disiloxanes and fluorides is effected on aluminum fluoride and sodium fluoride. Cleaning on sodium fluoride is effected at room temperature and at temperature of from 140 to 150 C in succession. EFFECT: low cost of process due to use of fluosilicic acid instead of hydrochloric or sulfuric acid; high degree of cleaning; possibility of obtaining pure magnesium fluoride; avoidance of wastes. 6 cl, 1 tbl, 1 ex