Embodiments of the invention generally relate to a method for etching in a processing platform (e.g. a cluster tool) wherein robust pre-etch and post-etch data may be obtained in-situ. The method includes the steps of obtaining pre-etched critical dimension (CD) measurements of a feature on a substrate, etching the feature; treating the etched substrate to reduce and/or remove sidewall polymers deposited on the feature during etching, and obtaining post-etched CD measurements. The CD measurements may be utilized to adjust the etch process to improved the accuracy and repeatability of device fabrication.