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

• Published in: Chemical vapor deposition Vol. 8; no. 4; pp. 163 - 170
• Main Authors: Williams, P. A., Roberts, J. L., Jones, A. C., Chalker, P. R., Tobin, N. L., Bickley, J. F., Davies, H. O., Smith, L. M., Leedham, T. J.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY‐VCH Verlag GmbH 01.07.2002
• Subjects: Alkoxide ligands donor‐functionalized; Hafnium dioxide; Liquid injection; MOCVD; Zirconium dioxide
• ISSN: 0948-1907; 1521-3862
• DOI: 10.1002/1521-3862(20020704)8:4<163::AID-CVDE163>3.0.CO;2-V

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. A range of excellent Zr and Hf alkoxide precursors have been developed for the MOCVD of ZrO2 and HfO2 thin films over a wide range of substrate temperatures. These mononuclear precursors (see Figure for an example) are volatile and significantly less reactive towards air and moisture than existing Zr and Hf alkoxide precursors. Analyses indicates that films are deposited in a thermodynamically stable α‐ or monolithic phase.