A.C. Characterization and modeling of lateral bipolar magnetotransistors

The a.c. characteristics of lateral bipolar magnetotransistors with dominant vertical injection are investigated. Calculations, supported by the experimental data show that the long base-transit-time and the large amount of charge stored in the base are responsible for the low alpha and beta cutoff frequencies. The experimental results provide new insight on the physical nature of their magnetosensitivity. More specifically, they present evidence that the magnetic field modulates the base-transit-time of the minority carriers inducing a differential current flow from the two collectors. Finally, but not less important, some issues related to the physical modeling of magnetotransistors are addressed.