A method of operating a semiconductor structure as a bipolar junction transistor, BJT, the semiconductor structure being a vertical bi-directional bipolar junction transistor, BJT, structure, comprising: a base region of a first conductivity type, wherein said base region constitutes a drift region of said structure; first and second collector/emitter, CE, regions, adjacent opposite vertical ends of said base region, each CE region of a second conductivity type, and each CE region disposed symmetrically about a vertical axis of the vertical bi-directional BJT structure; wherein said base region is lightly doped relative to said CE regions; the semiconductor structure further comprising: a base connection of the first conductivity type, wherein said base connection is highly doped relative to said base region, the base connection formed within said first CE region and disposed on the vertical axis of the vertical bi-directional BJT structure; first and second collector/emitter electrodes, (CE1, CE2) electrically connected to the first and second CE regions, respectively; and a base electrode (BASE) connected to the base connection; and wherein said first CE region has a greater thickness than the base connection; and the method comprising: supplying the base electrode with a base electrical voltage; and supplying the first and second collector/emitter electrodes with first and second collector/emitter electrical voltages, respectively. a base region of a first conductivity type, wherein said base region constitutes a drift region of said structure; first and second collector/emitter, CE, regions, adjacent opposite vertical ends of said base region, each CE region of a second conductivity type, and each CE region disposed symmetrically about a vertical axis of the vertical bi-directional BJT structure; wherein said base region is lightly doped relative to said CE regions; the semiconductor structure further comprising: a base connection of the first conductivity type, wherein said base connection is highly doped relative to said base region, the base connection formed within said first CE region and disposed on the vertical axis of the vertical bi-directional BJT structure; first and second collector/emitter electrodes, (CE1, CE2) electrically connected to the first and second CE regions, respectively; and a base electrode (BASE) connected to the base connection; and wherein said first CE region has a greater thickness than the base connection; and the method comprising: supplying the base electrode with a base electrical voltage; and supplying the first and second collector/emitter electrodes with first and second collector/emitter electrical voltages, respectively. a base connection of the first conductivity type, wherein said base connection is highly doped relative to said base region, the base connection formed within said first CE region and disposed on the vertical axis of the vertical bi-directional BJT structure; first and second collector/emitter electrodes, (CE1, CE2) electrically connected to the first and second CE regions, respectively; and a base electrode (BASE) connected to the base connection; and wherein said first CE region has a greater thickness than the base connection; and the method comprising: supplying the base electrode with a base electrical voltage; and supplying the first and second collector/emitter electrodes with first and second collector/emitter electrical voltages, respectively. supplying the base electrode with a base electrical voltage; and supplying the first and second collector/emitter electrodes with first and second collector/emitter electrical voltages, respectively.