Novel Mononuclear Alkoxide Precursors for the MOCVD of ZrO2 and HfO2 Thin Films

Abstract

Thin films of ZrO2 and HfO2 have been deposited by liquid injection metal–organic (MO)CVD using a range of new alkoxide precursors, [Zr(OtBu)2(mmp)2] (1), [Hf(OtBu)2(mmp)2] (2), [Zr(mmp)4] (3), and [Hf(mmp)4] (4): (mmp = 1-methoxy-2-methyl-2-propanolate, OCMe2CH2OMe). The complexes are mononuclear and volatile, and are significantly less reactive to air and moisture than existing Zr and Hf alkoxide precursors such as [Zr(OtBu)4] and [Hf(OtBu)4]. The ZrO2 and HfO2 films were grown over a wide range of substrate temperatures (350–650 °C), and analysis by laser Raman spectroscopy shows that the films were deposited in the thermodynamically stable α− or monoclinic phase.