Experimental DC Extraction of the Base Resistance of Bipolar Transistors: Application to SiGe:C HBTs

Abstract

This paper presents an improved variant of a dc method to experimentally evaluate the base resistance of a bipolar transistor. The technique relies on a device model associated with a simple parameter optimization methodology, and is suited for modern technologies wherein self-heating and impact-ionization effects play a relevant role. The approach is successfully applied to state-of-the-art SiGe:C heterojunction bipolar transistors for high-frequency applications, although it can in principle be exploited for any bipolar device. The accuracy of the method is verified by numerical and experimental procedures.

A Critical Review of Techniques for the Experimental Extraction of the Thermal Resistance of Bipolar Transistors from DC Measurements—Part I: Thermometer-Based Approaches

“…The Si/SiGe NPN HBT was fabricated by Infineon Technologies AG in the framework of the European Project DOTFIVE. The device has only one base and one collector contact (BEC configuration), and belongs to the latest project technology stage, also denoted as set #3 in [18,44]. The drawn emitter area is equal to 0.2 × 2.8 µm 2 , and the substrate is 185 µm thick.…”

“…This offers high flexibility throughout the whole investigation. The collector current I C in forward active mode is expressed as [15,44,45]…”

Advanced thermal simulation of SiGe:C HBTs including back-end-of-line

“…Measurements were performed on single-emitter SiGe:C NPN HBTs with one base contact and one collector contact (BEC configuration) manufactured by IFX within the DOTFIVE project; more specifically, the DUTs belong to the latest technology stage of the project development, also denoted as set #3 in [13,20]. Further detailsincluding the key figures of the setscan be found in [13] and are omitted here for the sake of brevity.…”