An 850 nm SiGe/Si HPT with a 4.12 GHz maximum optical transition frequency and 0.805A/W responsivity

Zerihun Gedeb Tegegne (1) , Carlos Viana (1) , Marc D Rosales (2, 1) , Julien Schiellein (1) , Jean-Luc Polleux (1) , Marjorie Grzeskowiak (1) , Elodie Richalot (1) , Catherine Algani (1)

1 ESYCOM - Electronique, Systèmes de communication et Microsystèmes
2 UP System - University of the Philippines

A 10 × 10 μm2 SiGe heterojunction bipolar photo-transistor (HPT) is fabricated using a commercial technological process of 80 GHz SiGe bipolar transistors (HBT). Its technology and structure are first briefly described. Its optimal opto-microwave dynamic performance is then analyzed versus voltage biasing conditions for opto-microwave continuous wave measurements. The optimal biasing points are then chosen in order to maximize the optical transition frequency (fTopt) and the opto-microwave responsivity of the HPT. An opto-microwave scanning near-field optical microscopy (OM-SNOM) is performed using these optimum bias conditions to localize the region of the SiGe HPT with highest frequency response. The OM-SNOM results are key to extract the optical coupling of the probe to the HPT (of 32.3%) and thus the absolute responsivity of the HPT. The effect of the substrate is also observed as it limits the extraction of the intrinsic HPT performance. A maximum optical transition frequency of 4.12 GHz and an absolute low frequency opto-microwave responsivity of 0.805A/W are extracted at 850 nm.

Mots clés: Microwave photonics; Si-based devices; IC technologies

Domaines: Electromagnétisme; Optique / photonique

Zerihun Gedeb Tegegne, Carlos Viana, Marc D Rosales, Julien Schiellein, Jean-Luc Polleux, et al.. An 850 nm SiGe/Si HPT with a 4.12 GHz maximum optical transition frequency and 0.805A/W responsivity. International Journal of Microwave and Wireless Technologies, 2017, 9 (1), pp.17-24. ⟨10.1017/S1759078715001531⟩. ⟨hal-01436955⟩