Emitter compensation effect

An energy band gap narrowing model based on experimental results enabled accurate calculations, for the first time, of all room temperature bipolar parameters of a modern high performance device. After these successful calculations, efforts were made to predict new effects in bipolar devices. It was found that β and fTincrease significantly, according to calculations, when compensation was eliminated in the emitter. Measurements made on bipolar devices at room temperature show a factor of two increase in β when the emitter compensation is reduced. Diode measurements of the compensation dependent energy gap made at 77°K show consistency with the measured increase in transistor β.