Abstract Polycrystalline germanium (Ge) thin films were grown by metal organic chemical vapor deposition (MOCVD) using tetra-allyl germanium [Ge(allyl)4], and germane (GeH4) as precursors. Ge thin films were grown on a TiN(50 nm)/SiO2/Si substrate by varying the growth conditions of the reactive gas (H2), temperature (300-700oC) and pressure (1-760Torr). H2 gas helps to remove carbon from Ge film for a Ge(allyl)4 precursor but not for a GeH4 precursor. Ge(allyl)4 exhibits island growth (VW mode) characteristics under conditions of 760Torr at 400-700oC, whereas GeH4 shows a layer growth pattern (FM mode) under conditions of 5Torr at 400-700oC. The activation energies of the two precursors under optimized deposition conditions were 13.4 KJ/ mol and 31.0 KJ/mol, respectively. Key words Tetra-allyl Germanium, germane, metal organic chemical vapor deposition, TiN.