Abstract: A method for etching an organic bottom antireflective coating (OBARC) and a photoresist material in a single etching process. The method comprises the steps of etching the OBARC and trimming the photoresist material at the same time in an etching environment using a substantially isotropic etching operation. The etching environment including an etching chamber with a top electrode and a bottom electrode wherein a mixture of abrasive gases can flow therethrough. Using an endpoint detection test to determine when an exposed portion of OBARC has been removed, the exposed portion of OBARC being an area of OBARC without photoresist protection and exposed to the etching environment. Applying an over-etch step to trim the photoresist to a desired dimension where the time of the over-etch step being based on the percentage of an endpoint time and the process condition of the over-etch step being same as that of the endpoint step.