consistent with an example embodiment , a bipolar transistor comprises an emitter region vertically separated from a collector region in a substrate by a base region . the bipolar transistor further comprises a field plate electrically connected to the emitter region ; the field plate extends from the emitter region along the base region into the collector region and the field plate is laterally electrically insulated from the base region and the collector region by a spacer . the spacer comprises an electrically isolating material that includes a silicon nitride layer and is vertically electrically isolated from the substrate by a further electrically isolating material .