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The hydrogen content in aerosol particles of a-Si : H, forming during pyrolysis of silane, is studied by means of the methods of hydrogen evolution and IR spectroscopy. The conclusion is drawn that the evolution peaks at 650,730, and 750 to 850 K correspond to hydrogen present in the dihydride groups of polysilane chains, the monohydride groups of the clustered phase, and the monohydride groups of the dilute phase, respectively. In the IR spectra the monohydride groups of the clustered phase cause absorption near 2000 cm-' and the monohydride groups of the dilute phase near 2100 cm-'. Under low silane conversion the main fraction of hydrogen is contained in (SiHJ", under conversion more than 50% in monohydride groups. MeTonaMH 3@@y3AA BOnOpOna II MK CneKTpOCKOIIHH H3yYaJIOCb COAepXaHAC BOnOpOAa B a3pO-30JTbHblX YaCTHUaX a-Si : H, 06pasym~xcs npA IIHpOJIH3e CAJIaHa. EbIn CAeJlaH BbIBOA, YTO Ha6JIWAae-MbIe nHKM 3@@Y3HH npH 650, 730 H 750 a0 850K 06yCJIOBneHbI BOnOpOnOM, HaXOHBUIHMCB B AHrHAPIIAHbIX rpyIIIIaX IIOjIHCllnaHOBbIX UtXOqeK, MOHOrAAPHfiHbIX rpyIIIIaX K-7XTepHpOBaHHOg @3bI H MOHOrHAPHAHbIX rpyIIIIaX "pa3peXeHHOfi" @a361 COOTBCTCTBeHHO. B MK-cneKTpax MOHOTH-UPHAHbIM rpynnaM KJIaCTepHpOBaHHO~ @3bI COOTBeTCTByeT IIOrJIOWeHlre B6JTH3A 2000 CM -' , a MOHOTA&-JHnHbIM rpynnaM " p a 3 p e x e~~o 8 " @ a m B6JTH3H2 100 CM-n p~ ManbIx cTenemx pasnoxe-H H I~ cHnaHa ocHoBHas nona Bonopona coAepxHTca B (SiH2),,, a n p~ cTeneHIi p a 3 n o x e~~s 6onee 50% B MOHOTHAPHnHblX rpyIInaX. ') 630090 Novosibirsk, Russia.44 A. A. ONISCHUK, V. P. STRUNIN, M. A. USHAKOVA, and V. N. PANFILOV in the conditions of [ l l ] and with the reaction time t = 0.50 s the surface initiation occursonly at reactor temperatures T 2 825 K, i.e. when 1 -0 2 0.12. As follows from estimations, the aerosol particles in the gas phase can also contribute to silane decomposition. Therefore, to understand the mechanism of silane decomposition, it is necessary to study the formation of aerosol particles and their role in pyrolysis.This paper continues the studies [l 1,161 of the mechanism of silane thermal decomposition in the conditions of aerosol formation. In [ l l , 161 the main attention has been paid to the influence of aerosol particles deposited on the reactor walls on the process of pyrolysis as well as to the parallel dependence of the concentration of the gas-phase products of pyrolysis and certain parameters of the aerosol particles (concentration, size, morphology) on the degree of silane conversion. In this work, using the same experimental conditions as in [ll, 161, we have studied the hydrogen content in aerosol particles depending on the degree of silane conversion. Comparing our results with those obtained in [ l l , 161 we will provide additional insight into the understanding of the role of aerosol particles in the thermal decomposition of silane.