Verfahren zur Herstellung von Metallalkylverbindungen und deren Verwendung

Metallalkyle, z. B. Trimethylindium, fallen zumeist als Etherate an, z. B. (CH3)3InO(CnH2n+1)2, die eine thermische Etheratspaltung erforderlich machen. Auf lithiumorganischem Weg erfolgt eine chemische Etherverdraengung durch eine Umsetzung nach den Reaktionsgleichungen: MX3 + 4 MELi ? (Me4M)Li(OEt2)3 (M = In, Ga, Al; X = Cl, Br, J; Me = CH3; Et = CnH2n+1) 3(Me4M)Li + MX3 ? 4 Me3M + 3 LiX Aus dem Reaktionsgemisch wird Me3M durch Destillation isoliert. Herstellung hochreiner Metallalkyle als Quellenmaterial fuer metallorganische Gasphasenepitaxie zur Halbleiterherstellung.

WO 8905303 A UPAB: 19950110 Prodn. of metal alkyl cpds. MR3 (I) is carried out by reacting a mixed alkali metal or Mg M alkyl cpd. M'MR4 (II) or M''(MR4)2 (III), freed from coordinated ether or ether-type solvent, with the stoichiometric amt. of an alkyl-metal halide MXzR3-2 (IV) and distn. of (I) from the remaining alkali or Mg halides; M = In, Ga or Al; R = 1-10C alkyl, which can be branched, cyclic or unsatd., and 6-10C aryl. Pref. (II) and (III) are freed from ether or similar solvents by heating in vacuo, washing with an inert organic solvent and/or drying in vacuo; pref. byheating in vacuo to 100 deg.C and washing with an aliphatic or aromatic solvent. (II) and (IV) with z = 3 are reacted in 3:1 ratio. Reaction is carried out in an aliphatic or aromatic solvent (pref. pentane, hexane, benzene, toluene, xylene or mesitylene), solvent is removed by vacuum distn. and (I) is isolated in highly pure form by fractional distn. at atmos. pressure. USE/ADVANTAGE - (I) are claimed for use as source material for the prodn. of semicondcutor films by gas phase epitaxy. They can beproduced in very high purity and yield.