A low temperature self-reducible copper hydroxide amino-alcohol complex catalyzed by formic acid for conductive copper films

Copper hydroxide possesses a much higher copper content and lower price than other copper salts, however it decomposes to cupric oxide and water upon heating, restricting it as a self-reducible copper precursor. In this study, a novel self-reducible copper hydroxide complex with amino-alcohol is successfully developed. Copper hydroxide was converted to a self-reducible complex with 3-dimethylamino-1,2-propanediol (DMAPD), in which the copper ions could be reduced to elementary copper at suitable temperatures. Moreover, the addition of a small amount of formic acid can catalyze the self-reduction of the complex to copper completely. In particular, the self-reduction temperature could be reduced to about 130 degrees C and the sintered films exhibited good electrical conductivity. A possible cyclic reduction mechanism showing the catalytic effect of formic acid was proposed. This low temperature sintering self-reducible complex makes copper hydroxide a new potential copper source for the fabrication of conductive copper films.