Thin Solid Films, Vol.249, No.1, 22-27, 1994
Nonselective Copper Film Growth on Kapton (Polyimide) by MOCVD
High-purity polycrystalline Cu films have been deposited for the first time on a commercial polyimide using thermal, cold-wall, reduced-pressure (20 Torr) MOCVD. Two precursors were employed; Cu(acac)(2) and Cu(HFA)(2). The deposition temperature ranged from 275 to 425 degrees C and the source temperature ranged from 85 to 150 degrees C depending on the source involved. The reaction proceeded with and without the help of H2O vapor. When H2O was used, the film growth rate was up to 420 Angstrom min(-1) and grain sizes up to 1.5 mu m were obtained in the case of the Cu(HFA)(2) source. H2O significantly increased the growth rate in the case of the Cu(acac), source. When H,O was not used, with either source, the grain size was smaller (0.7-1.1 mu m) and the films were physically more optically reflective. In the first few minutes of the deposition, the deposited film consisted entirely of the copper oxide phase. As the reaction continued, pure Cu films were obtained. The films were characterized using XRD, LVSEM, SAXPS and RBS. Electrical resistivity of 3.25 mu Omega cm was measured for films prepared with deposition temperatures of 420 degrees C and in the presence of H2O vapor. Simple Scotch-tape adhesion tests revealed qualitatively that the deposited films adhere well to the polyimide substrate.