A process for etching a film layer on a semiconductor wafer is disclosed. The process is particularly well suited to etching carbon containing layers, such as hardmask layers, photoresist layers, and other low dielectric films. In accordance with the present disclosure, a reactive species generated from a plasma is contacted with a surface of the film layer. Simultaneously, the substrate or semiconductor wafer is subjected to rapid thermal heating cycles that increase the temperature past the activation temperature of the reaction in a controlled manner.