Gain control of integrated circuit lateral transistors by electron irradiation

Due to the limitations of photolithography, the base width of a lateral complementary PNP transistor cannot usually be controlled to be as narrow as the double-diffused PNP transistor in the same block, and the cut-off frequency is considerably lower. If the lateral transistor is connected in a common emitter configuration within the feedback loop of an amplifier, the lower cutoff frequency may cause excessive phase-shift and result in instability of the amplifier. The phase-shift can be reduced by decreasing the lifetime and hence the gain of the lateral transistor.