A method of patterning an insulation layer is described. The method includes preparing a film stack on a substrate, wherein the film stack comprises a cap layer, a SiCOH-containing layer overlying the cap layer, and a hard mask overlying the SiCOH-containing layer. The method further includes transferring a pattern through the film stack by performing a series of etch processes in a plasma etching system, wherein the series of etch processes utilize a temperature controlled substrate holder in the plasma etching system according to a substrate temperature control scheme that achieves etch selectivity between the SiCOH-containing layer and the underlying cap layer.