Analytical base-col lector depletion capacitance in vertical SiGe heterojunction bipolar transistors fabricated on CMOS-compatible silicon on insulator

作者：Xu Xiao-Bo^*; Zhang He-Ming; Hu Hui-Yong; Ma Jian-Li; Xu Li-Jun

来源：Chinese Physics B, 2011, 20(1): 018502.

DOI：10.1088/1674-1056/20/1/018502

• depletion capacitance
• heterojunction bipolar transistors
• thin film silicon on insulator
• SiGe

The base-collector depletion capacitance for vertical SiGe npn heterojunction bipolar transistors (HBTs) on silicon on insulator (SOI) is split into vertical and lateral parts. This paper proposes a novel analytical depletion capacitance model of this structure for the first time. A large discrepancy is predicted when the present model is compared with the conventional depletion model, and it is shown that the capacitance decreases with the increase of the reverse collector-base bias-and shows a kink as the reverse collector-base bias reaches the effective vertical punch-through voltage while the voltage differs with the collector doping concentrations, which is consistent with measurement results. The model can be employed for a fast evaluation of the depletion capacitance of an SOI SiGe HBT and has useful applications on the design and simulation of high performance SiGe circuits and devices.

• 出版日期2011-1
• 单位西安电子科技大学