ABSTRACT
Figure 2 shows the common-emitter characteristics for the InGaP/DGSL-and DGSL-passivated CEHBT's. A small collect-emitter offset voltage of 55 mV and knee voltage of 0.3 V at a collector current of 1 rnA were obtained for both devices. These phenomena reveal that the DGSL structure really eliminates the spike resulting from L'1Ec. Figure 3 shows the Gummel plots of InGaP/DGSL-and DGSL-passivated CEHBT's with VBc=O V. We firstly refer to the DGSL-and the AlGaAs-passivated devices. An important merit of the DGSL-passivated HBT is its V ON(B-E) defined as V BE at which the collector current exceeds 1 flA. The V ON(B-E) of DGSL-passivated CEHBT is 0.87 V, which is 0.4 V lower than the 1.27 V measured in an AlGaAs-passivated HBT over a wide range of current level.
