Comparison of Thermal and Mass-Transport Properties of Bi(tmhd)3, Bi(p-tol)3, and Bi(o-tol)3 MOCVD Precursors

Metal-organic (MO)CVD processes using three different precursors (Bi(tmhd)3, Bi(p-tol)3, and Bi(o-tol)3) have been investigated. Combined, thermal, and mass spectroscopic investigations have provided information on their thermal robustness during sublimation processes. In-situ Fourier-transform infrared (FTIR) measurements have allowed the monitoring of mass-transported precursors during MOCVD experiments. Temperature windows of 190–277 °C, 170–270 °C, and 150–220 °C have proved suitable for the efficient vaporization of Bi(tmhd)3, Bi(p-tol)3, and Bi(o-tol)3, respectively, even though aryl precursors have proved to be more stable than β-diketonate during the sublimation and transport processes.Above 350 °C, decomposition during the MOCVD processes has been observed for all the precursors. In the case of Bi(tmhd)3 and Bi(o-tol)3 it involves the ligand fragmentation, while for Bi(p-tol)3, dissociation of the intact aryl ring seems to occur.