Copper chemical vapour deposition using copper(I) hexafluoroacetylacetonate trimethylvinylsilane

Abstract

The effects of the deposition temperature on the microstructure and the electrical resistivity of copper films prepared by chemical vapour deposition (CVD) were studied at the deposition temperatures between 160 degrees C and 330 degrees C. Copper films were prepared on titanium nitride (TiN) substrates in a low-pressure warm-wall reactor using copper(I) hexafluoroacetylacetonate trimethylvinylsilane, Cu (hfac) (TMVS), as the precursor. The activation energy for the deposition was found to be 45.4 kJ mol(-1) at the total pressure of 66.7 Pa. The films deposited at below 200 degrees C, where the deposition is limited by surface reaction, were dense and had low resistivity of approximately 2 mu Omega cm. Moreover, they exhibited excellent step coverage. However, the films deposited at above 200 degrees C, where the mass transport processes become important, were composed of poorly connected globular grains, resulting in considerably high resistivities and rough surfaces. Effects of the deposition temperature on the grain size and the preferred orientation of the films were also investigated.