Frequency Response of Bipolar Junction Transistors after Electron-Beam irradiation

The effect of electron-beam irradiation on the frequency response of modern bipolar transistors has been measured. The electron energies used are typical of those used in e-beam lithography. While the current gain of the transistors at dc is sharply reduced, the high-frequency response is virtually unchanged. This result demonstrates that the frequency response is limited by the base transit line. © 1989 IEEE