ALCOHOLATES OF RARE EARTH MTALS A PRECURSORS FOR METALOXIDE LAYERS OR FILMS

Rare earth metal precursors, for use in MOCVD techniques have a ligand of the general formula OCR1(R2)CH2X, wherein R1 is H or an alkyl group, R2 is an optionally substituted alkyl group and X is selected from OR and NR2, wherein R is an alkyl group or a substituted alkyl group. Methods of making such precursors and methods of depositing metal oxide layers from such precursors are also described.