A method and system for controlling a dimension of an etched feature. The method includes: measuring a mask feature formed on a top surface of a layer on a substrate to obtain a mask feature dimension value; and calculating a mask trim plasma etch time based on the mask feature dimension value, a mask feature dimension target value, a total of selected radio frequency power-on times of a plasma etch tool since an event occurring to a chamber or chambers of a plasma etch tool for plasma etching the layer, and an etch bias target for a layer feature to be formed from the layer where the layer is not protected by the mask feature during a plasma etch of the layer.