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. Thermal and mass transport properties of Bi(tmhd)3, Bi(p‐tol)3, and Bi(o‐tol)3 MOCVD precursors have been investigated by combined, in‐situ FT‐IR and ex‐situ thermal and mass spectroscopic measurements. Temperature windows of 190–277 °C, 170–270 °C, and 150–220 °C prove suited to 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 during sublimation and transport processes compared to the β‐diketonate. For all the precursors, the MOCVD decomposition process starts above 350 °C. In the case of Bi(tmhd)3 and Bi(o‐tol)3 it involves ligand fragmentation; for Bi(p‐tol)3 the dissociation of the intact aryl ring seems to occur.