HETEROJUNCTION BIPOLAR-TRANSISTOR WITH AN ADDITIONAL MINORITY-CARRIERREFLECTION BARRIER IN THE EMITTER

A heterojunction bipolar transistor (HBT) structure that provides an a dditional minority carrier reflection/confinement barrier within the q uasi-neutral emitter region has been proposed and investigated by mean s of numerical simulations. The proposed device structure has been dem onstrated to perform better than conventional HBTs - a higher current gain with better uniformity, which has been achieved without affecting the high frequency performance. In addition, the current gain was fou nd to be relatively insensitive to temperature changes in the range of 250 K to 450 K, thus making the new device structure more suitable fo r high power applications.