Solid-state electrochemical nanoimprinting of copper

For the first time, the authors report highly selective dry etching of copper with a resolution of 80nm using solid-state electrochemical nanoimprint technology. By exploiting the high mobility of copper ions in solid electrolytes such as copper sulfide, they are able to obtain etching rates up to 5A∕s without the use of contaminating liquids and excessive mechanical forces. Given the dearth of dry etch processes for metals in general and the fact that nanopatterning of metals is typically achieved indirectly using multistep processes, such a direct patterning technique offers potential application in a number of process steps in metallic interconnects and other nanoscale device fabrication.