Recombination in the Ge-spiked monoemitter of the SiGe:C HBTs

摘要

A SiGe spike in the monoemitter of a SiGe:C HBT locally increases the recombination rate. The narrower energy bandgap of SiGe compared to Si increases the minority charge storage, resulting in higher recombination rate. The SiGe spike acts as a virtual contact and increases the base current. This results in lower current gain, and hence higher BV_(CEO)- This paper studies the physical mechanism for this higher recombination rate in the SiGe spike, and it calculates the minority carrier lifetime in the SiGe spike.