WET ETCHING RATE OF NICKEL IRON ALLOY

The etch rate of 42 Alloy in iron (III) chloride etchant is measured i n order to investigate the effects of agitation speed, etchant concent ration, temperature, co-existing foreign metal ions and resist hole di ameter. The rate increased at first and gradually decreased in accorda nce with increasing etchant concentration. The activation energies are 12 and 24-30 kJ/mol at a low concentration and at a higher concentrat ion, respectively. Foreign metal ions in etchants significantly suppre ssed the etch rate. The etch rate increased with decreasing diameter o f the resist hole due to the effect of side etch.