Comparison between MBE-based SiGe/Si HBT and Si-based bipolar transistor technologies

In the paper, the comparison between MBE-based SiGe/Si heterojunction bipolar transistors (HBT) technologies and Si bipolar transistors technologies is made. The SiGe/Si film used in the present work was grown by solid source molecular beam epitaxy (MBE) system. 3 μm process technology was used to develop SiGe HBT devices. The experimental results indicate that both the direct current (DC) characteristics and the cutoff frequency of SiGe HBT are satisfactory. The current gain β of HBT devices is 50, when the collector voltage V_C=2 V and the collector current I_C=5 mA. The cutoff frequency f_T=5.1 GHz, and the uniformity of the cutoff frequency of HBT is quite good. With the same layout, 3 μm process technology was used to develop Si bipolar transistor devices. The measured results show that the cutoff frequency f_T of the Si devices is 1.5 GHz