Anomalous local laser etching of copper by chlorine

Etching of copper films by chlorine is induced by a scanning cw laser that locally heats the tllm. In experimental regimes with relatively high laser power, low chlorine pressure and fast scan speed, laser etching of copper is well characterized by a kinetic model based on the calculated temperature rise. In other regimes, a thick nondesorbed copper chloride layer forms on top of the etched copper region that significantly decreases the rate of copper chlorination. Notably, in certain regimes the copper etch depth is shown to increase with increasing scan rate, which is a very unusual dependence.