By Topic

Base thickness and high-frequency performance of SiGe HBT's

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

4 Author(s)

Summary form only given. The influence of the base thickness on the high-frequency performance of about 20 fabricated HBTs (heterojunction bipolar transistors) has been analyzed by plotting the highest obtained fT value against base thickness. Base thickness is defined as the distance between the two Si/SiGe interfaces which usually coincide with the metallurgical pn-junctions. A steady increase of fT with decreasing base thickness can be clearly seen: starting from the first published HBTs with 50 nm base thickness which did not exceed 20 GHz, transistors with 40 nm base had 37-52 GHz and devices with 28-30 nm bases exhibited 58-91 GHz. The latest two samples had only 25 and 22 nm base thicknesses, leading to an fT of 95 GHz (fmax=50 GHz), the highest value reported for Si transistors. The base doping in the latter sample was 8×1019 cm-3 to maintain a base sheet resistance of about 1.2 kΩ

Published in:

Electron Devices, IEEE Transactions on  (Volume:40 ,  Issue: 11 )