Semiconductor device and forming method thereof

Embodiments include a first set of fins having an emitter of a bipolar junction transistor (BJT) disposed over the first set of fins, a second set of fins having a base of the BJT disposed over the second set of fins, and a third set of fins having a collector of the BJT disposed over the third set of fins. A first gate structure is disposed over the first set of fins adjacent to the emitter. A second gate structure is disposed over the second set of fins adjacent to the base. A third gate structure is disposed over the third set of fins adjacent to the collector. The first gate structure, second gate structure, and third gate structure are physically and electrically separated. The embodiment of the invention also relates to a semiconductor device and a forming method thereof. 实施例包括：第一组鳍，具有设置在第一组鳍上方的双极结晶体管(BJT)的发射极；第二组鳍，具有设置在第二组鳍上方的BJT的基极；以及第三组鳍，具有设置在第三组鳍上方的BJT的集电极。第一栅极结构设置在与发射极相邻的第一组鳍上方。第二栅极结构设置在与基极相邻的第二组鳍上方。第三栅极结构设置在与集电极相邻的第三组鳍上方。第一栅极结构、第二栅极结构和第三栅极结构物理和电隔离。本发明的实施例还涉及半导体器件及其形成方法。