Synthesis, crystal structure and mass transport properties of novel thallium ion precursors for MOCVD applications

Abstract

The reaction of Tl₂CO₃ with 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (Hhfa) and diglyme {CH₃O(CH₂CH₂O)₂CH₃} or tetraglyme {CH₃O(CH₂CH₂O)₄CH₃} in dichloromethane yields the anhydrous, thermally and air stable, volatile Tl(hfa)·diglyme and Tl(hfa)·tetraglyme adducts. They have been characterized by single crystal X-ray diffraction, elemental analysis, ¹H and ¹³C NMR, IR and mass spectroscopy. Thermal and mass-transport properties have been investigated using thermogravimetric and differential scanning calorimetric measurements. There is evidence that both precursors are very low melting and volatile, and can be used as liquid Tl sources. Both adducts have been successfully applied to metal–organic chemical vapor deposition of thallium containing films.