Aspects of the invention provide a method of forming a bipolar junction transistor. The method includes: providing a semiconductor substrate including a uniform silicon nitride layer over an emitter pedestal, and a base layer below the emitter pedestal; applying a photomask at a first end and a second end of a base region; and performing a silicon nitride etch with the photomask to simultaneously form silicon nitride spacers adjacent to the emitter pedestal and exposing the base region of the bipolar junction transistor. The silicon nitride etch may be an end-pointed etch.