Method for improving CD micro-loading in photomask plasma etching

Embodiments of the present invention provides methods to etching a mask layer, e.g., an absorber layer, disposed in a film stack for manufacturing a photomask in EUV applications and phase shift and binary photomask applications. In one embodiment, a method of etching an absorber layer disposed on a photomask includes transferring a film stack into an etching chamber, the film stack having a chromium containing layer partially exposed through a patterned photoresist layer, providing an etching gas mixture including Cl2, O2 and at least one hydrocarbon gas in to a processing chamber, wherein the Cl2 and O2 is supplied at a Cl2:O2 ratio greater than about 9, supplying a RF source power to form a plasma from the etching gas mixture, and etching the chromium containing layer through the patterned photoresist layer in the presence of the plasma.