Development and vapour pressure of metallo-organic precursors of copper for the deposition of copper thin films by a plasma-assisted MOCVD

ABSTRACT

A group of metallo-organic complexes of copper, namely bis(N-R-salicylaldiminato)Cu(II) (R: methyl to n-pentyl, hereafter referred to as 1–5) were prepared and their volatile nature was confirmed by TG/DTA. The molecular masses (M) of 1–5 were confirmed by mass spectrometry. The vapour pressure (p_e ) for precursors 1–5 determined by a transpiration technique using the Clausius–Clapeyron relation yielded the values of 91 ± 2, 84 ± 4, 100 ± 2, 92 ± 2, and 72 ± 2 kJ mol⁻¹ for ΔH^o _vap, respectively, for 1–5. The thin films deposited by plasma-assisted MOCVD technique contain predominantly metallic copper in <111> orientation. The SEM images of the thin films exhibit continuous nanoball-like structure.

KEYWORDS:

• Copper precursors
• vapour pressure
• copper coating by MOCVD

Acknowledgments

The authors thank UGC for awarding FIP for M.G. Johnson. The authors also thank Central Drug Research Institute, Lucknow, for recording FABMS and for C, H, and N analyses.