Dirk Wolansky

A 0.13

A 0.13 µm SiGe BiCMOS technology for millimeter wave applications is presented. This technology features high-speed HBTs (f<inf>T</inf>=240 GHz, f<inf>max</inf>=330 GHz, BV<inf>CEO</inf>=1.7 V) along with high-voltage HBTs (f<inf>T</inf>=50 GHz, f<inf>max</inf>=130 GHz, BV<inf>CEO</inf>=3.7 V) integrated in a dual-gate, triple-well RF-CMOS process. Ring oscillator gate delays of 2.9 ps, low-noise amplifiers for 122 GHz, and LC oscillators for frequencies above 200 GHz are demonstrated.

\mu{\hbox {m}}

We investigate the impact of defects on the leakage currents of Si/SiGe/Si heterojunction bipolar transistors (HBTs). We demonstrate that threading dislocations in the HBT layer stack strongly increase the leakage currents. Such defects can be formed during an a neal step for the high-dose implantation commonly used to prepare a low-ohmic subcollector. Defect bands and threading dislocations were observed in case of P implantation while Sb implant ation leads to defect-free layers and devices with a low leakage current level. We also show that defects arising during the deposition process of the epitaxial Si/SiGe/Si layer stack have a strong impact on the leakage currents of HBTs. Darkfield microscopy was applied to evaluate the surface defect density of deposited Si/SiGe/Si layer stacks. We demonstrate that this me thod is very sensitive and capable for a defect-related layer classification, and that there is a c orrelation between the different defect classes and the leakage currents. Introduction The radio frequency (RF) performance of Si/SiGe/Si-npn HBTs has be en tr mendously improved over the last 10 years [1,2]. Si/SiGe/Si HBTs are no longer niche devices, in particular when embedded in a BiCMOS technology which strongly increases the require ments of HBT yield and reliability. The improvement of the HBT RF performance is a res ult of a strong reduction of the lateral and vertical device dimensions combined with increased doping l evels. Defect-free fabrication of highly doped BiCMOS HBTs is a challenge. It require s th analysis of the fabrication process with respect to defect sources and a careful choice of the process conditions for defectcritical steps, like implantations, anneals, or deposition of epitaxia l layers. Moreover, suitable methods for defect detection and characterization are needed and the s pecific impact of different defects on the junction leakage currents has to be found out. In this paper we focus on implantation defects induced by high-dose implant ation applied for the formation of highly doped HBT subcollectors. We will demonstrate that t reading dislocations formed during the anneal step following the implantation, strongly incre ase the HBT leakage currents. In case of P implantation, we observed defect bands originati n such threading dislocations while Sb implantation led to defect-free layers and de vices with a low leakage current level. In the second part of the paper we show that defects arising during t he deposition process for the epitaxial Si/SiGe/Si layer stack have a strong impact on the HBT leakage currents, too. We will demonstrate that darkfield microscopy is a suitable method for a def ect-r lated layer classification and that there is a correlation between the different defect classes and HBT le akage currents. Solid State Phenomena Online: 2003-09-30 ISSN: 1662-9779, Vols. 95-96, pp 249-254 doi:10.4028/www.scientific.net/SSP.95-96.249

SiGe BiCMOS Technology Featuring f

Modular integration of photonic functionality in the front-end of line of a qualified 0.25 mum SiGe BiCMOS technology is considered. First measurements of electronic & waveguide test structures are presented.