Various embodiments of the present disclosure are directed towards a method for forming an integrated circuit (IC). The method includes forming a gate electrode and a gate dielectric stacked over a substrate. A sidewall spacer layer is deposited over the substrate and the gate electrode, in which the sidewall spacer layer lines sidewalls of the gate electrode. An etching back is performed on the sidewall spacer layer to form a sidewall spacer on the sidewalls of the gate electrode. The etching back is performed at an etch rate less than about 8 angstroms/minute using an etchant comprising hydrogen fluoride. Further, the substrate is doped with the sidewall spacer and the gate electrode in place to form a pair of source/drain regions respectively on opposite sides of the gate electrode.