Study of Lateral Scaling Impact on the Frequency Performance of SiGe Heterojunction Bipolar Phototransistor

Abstract

The influence of the lateral scaling such as emitter width and length on the frequency behavior of SiGe bipolar transistor is experimentally studied. Electrical transistors of different emitter sizes are designed and fabricated by using a commercial bipolar transistor technology. The effect of peripheral current and collector current spreading on electrical bipolar transistor performances are analyzed in regards to the state of the art. Furthermore, the lateral scaling effect on SiGe phototransistor electrical and opto-microwave frequency behavior is studied. The impact of the lateral flow of photo-generated carriers toward the optical opening in phototransistor structure is investigated. Moreover, the 2-D carrier flow effect on the opto-microwave frequency behavior of the phototransistor is characterized through optomicrowave scanning near-field optical microscopy measurements, in the course of which the intrinsic parameters, such as transit time and junction capacitances are extracted over the surface of the phototransistor. An intrinsic optical transition frequency of 6.5 GHz is measured for 10 × 10 µm 2 . Portugal, in 2010, and the Ph.D. degree in electronics, optoelectronics and systems from Université Paris-Est, Champs-sur-Marne, France, in 2014.Since 2010, he has been a Researcher with the ESYCOM Laboratory, ESIEE-Paris, Noisy-le-Grand, France. His research interest includes optoelectronic device developments, integration, and packaging for low cost radio-over-fiber technology applications.Jean-Luc Polleux received the master's/Diplôme d'ingénieur degree in microelectronic from ENSEIRB, Bordeaux, France, and the DEA degree in electronic and telecommunications from the University of Bordeaux 1, France, both in 1997, and the Ph.D. degree in the optomicrowave from CNAM, Paris, in 2001. He joined ESIEE-Paris, Université Paris-Est, France, and the joint ESYCOM Laboratory, where he is currently an Associate Professor. He is also an Administrator of Optics'Valley, Ile-de-France region, and the Head of the International Master of Electronics, ESIEE Paris, UPE. He published over 60 scientific publications and two patents. His current research involves microwave-photonics devices and systems for radio-over-fibre applications with special emphasis on microwave phototransistors (SiGe/Si and InGaAs/InP), silicon-based integration and packaging, analogue VCSELs, and opto-microwave devices modeling. He co-organized three international workshops and co-chaired the local committee of the French microwave conference JNM2013. He was a Guest

Substrate resistivity influence on silicon–germanium phototransistor performance

“…Moutier et al [2] identified the fastest and slowest regions of the HPT structure based on physical simulations. The lateral dimensioning effects such as the peripheral and twodimensional carrier flows are studied in [5]. In [6,7], the phototransistor performances are investigated through optoelectronic compact circuit modelling.…”

“…20 Ω•cm. The detailed schematic and specifications of the bipolar transistor technology used are the same as presented in [5,10,11]. The HPT fabrication does not modify the vertical stacks of layers of the standard bipolar transistor (HBT) technology.…”