Evaluation of Group 4 Metal Bis-cyclopentadienyl Complexes with Selenolate and Tellurolate Ligands for CVD of ME2 Films (E = Se or Te)

The selenolate and tellurolate complexes [Cp 2 M(SeR) 2 ] (M = Ti, Zr, or Hf; R = Me or Bu t ) and [Cp 2 M(TeBu t ) 2 ] (M = Zr or Hf) have been prepared and characterized by 1 H, 13 C{ 1 H}, 77 Se{ 1 H} and 125 Te{ 1 H} NMR spectroscopy and microanalysis. Crystal structures of representative examples are reported, together with the structure of the oxo-bridged species [{Cp 2 Zr(SeMe)} 2 (μ-O)] formed by partial hydrolysis. Trends in the NMR parameters are discussed. These molecular [Cp 2 M(SeBu t ) 2 ] complexes are shown to be suitable as precursors for the single source LPCVD of intensely colored MSe 2 thin films for each of the Group 4 elements, confirmed by SEM/EDX and PXD. These are the first examples of single source CVD of ZrSe 2 and HfSe 2 thin films. The corresponding [Cp 2 M(TeBu t ) 2 ] species (M = Zr or Hf) deposit elemental Te under similar LPCVD conditions.