Featured Research

from universities, journals, and other organizations

Extremely high-speed heterojunction bipolar transistors demonstrated

Date:
October 10, 2011
Source:
Interuniversity Microelectronics Centre (IMEC)
Summary:
Researchers have realized a fT/fMAX 245GHz/450GHz SiGe:C heterojunction bipolar transistor (HBT) device, a key enabler for future high-volume millimeter-wave low-power circuits to be used in automotive radar applications. These HBT devices also pave the way to silicon-based millimeter wave circuits penetrating the so-called THz gap, enabling enhanced imaging systems for security, medical and scientific applications.

Cross-section of bipolar HBT device in a B-E-B-C configuration after end-of-line processing.
Credit: Image courtesy of Interuniversity Microelectronics Centre (IMEC)

Imec realized a fT/fMAX 245GHz/450GHz SiGe:C heterojunction bipolar transistor (HBT) device, a key enabler for future high-volume millimeter-wave low-power circuits to be used in automotive radar applications. These HBT devices also pave the way to silicon-based millimeter wave circuits penetrating the so-called THz gap, enabling enhanced imaging systems for security, medical and scientific applications.

Related Articles


The extremely high-speed devices have a fully self-aligned architecture by self-alignment of the emitter, base and collector region, and implement an optimized collector doping profile. Compared to III-V HBT devices, SiGe:C HBTs combine high-density and low-cost integration, making them suitable for consumer applications. Such high-speed devices can open up new application areas, working at very high frequencies with lower power dissipation, or applications which require a reduced impact of process, voltage and temperature variations at lower frequencies for better circuit reliability.

To achieve the ultra high-speed requirements, state-of-the-art SiGe:C HBTs need further up-scaling of the device performance. Thin sub-collector doping profiles are generally believed to be mandatory for this up-scaling. Usually, the collector dopants are introduced in the beginning of the processing and thus exposed to the complete thermal budget of the process flow. This complicates the accurate positioning of the buried collector. By in-situ arsenic doping during the simultaneous growth of the sub-collector pedestal and the SiGe:C base, imec introduced both a thin, well controlled, lowly doped collector region close to the base and a sharp transition to the highly doped collector without further complicating the process. This resulted in a considerable increase of the overall HBT device performance: Peak fMAX values above 450GHz are obtained on devices with a high early voltage, a BVCEO of 1.7V and a sharp transition from the saturation to the active region in the IC-VCE output curve. Despite the aggressive scaling of the sub-collector doping profile, the collector-base capacitance values did not increase much. Moreover, the current gain is well defined, with an average around 400 and the emitter-base tunnel current, visible at low VBE values, is limited as well.

These outstanding results were realized within the framework of the European joint research project DOTFIVE which aims at developing SiGe:C HBT devices that operate at 500 GHz at room temperature.


Story Source:

The above story is based on materials provided by Interuniversity Microelectronics Centre (IMEC). Note: Materials may be edited for content and length.


Cite This Page:

Interuniversity Microelectronics Centre (IMEC). "Extremely high-speed heterojunction bipolar transistors demonstrated." ScienceDaily. ScienceDaily, 10 October 2011. <www.sciencedaily.com/releases/2011/10/111010121906.htm>.
Interuniversity Microelectronics Centre (IMEC). (2011, October 10). Extremely high-speed heterojunction bipolar transistors demonstrated. ScienceDaily. Retrieved April 19, 2015 from www.sciencedaily.com/releases/2011/10/111010121906.htm
Interuniversity Microelectronics Centre (IMEC). "Extremely high-speed heterojunction bipolar transistors demonstrated." ScienceDaily. www.sciencedaily.com/releases/2011/10/111010121906.htm (accessed April 19, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, April 19, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

At Least 15 Injured in a California Natural Gas Pipeline Explosion

At Least 15 Injured in a California Natural Gas Pipeline Explosion

Reuters - US Online Video (Apr. 18, 2015) At least 15 injred after natural gas transmission line ruptures in Fresno, California. Julie Noce reports. Video provided by Reuters
Powered by NewsLook.com
NASA Electric Rover Goes for a Spin

NASA Electric Rover Goes for a Spin

Reuters - Innovations Video Online (Apr. 17, 2015) NASA&apos;s prototype electric buggy could influence future space rovers and conventional cars. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Scientists Create Self-Powering Camera

Scientists Create Self-Powering Camera

Reuters - Innovations Video Online (Apr. 17, 2015) American scientists build a self-powering camera that captures images without using an external power source, allowing it to operate indefinitely in a well-lit environment. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
The State Of Virtual Reality

The State Of Virtual Reality

Newsy (Apr. 17, 2015) Virtual Reality is still a young industry. What’s on offer and what should we expect from our immersive new future? Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins