Featured Research

from universities, journals, and other organizations

High durability of nanotube transistors in harsh space environment demonstrated

Date:
September 18, 2012
Source:
Naval Research Laboratory
Summary:
Investigating the effects of prolonged exposure to ionizing radiation, researchers have demonstrated the ability of single walled carbon nanotube transistors to survive the harsh space environment.

A locally etched back-gated field effect transistor (FET) structure with a deposited dielectric layer. Thick dielectric layers are highly susceptible to radiation induced charge build-up, which is known to cause threshold voltage shifts and increased leakage in metal-oxide semiconductor (MOS) devices. To mitigate these effects, the dielectric layer is locally etched in the active region of the back-gated FET. A gate dielectric material is then deposited (depicted in red) over the entire substrate.
Credit: U.S. Naval Research Laboratory

U.S. Naval Research Laboratory electronics science and technology engineers demonstrate the ability of single walled carbon nanotube transistors (SWCNTs) to survive the harsh space environment, investigating the effects of ionizing radiation on the crystalline structures and further supporting the development of SWCNT-based nanoelectronics for use in harsh radiation environments.

"One of the primary challenges for space electronics is mitigating the susceptibility of prolonged exposure to radiation that exists in the charged particle belts that encircle Earth," said Cory Cress, materials research engineer. "These are the first controlled demonstrations showing little performance degradation and high tolerance to cumulative ionizing radiation exposure."

Radiation effects take two forms, transient effects and cumulative effects. The former, referred to as single effect transients (SETs), result from a direct strike by an ionizing particle in space that causes a current pulse in the device. If this pulse propagates through the circuit it can cause data corruption that can be extremely detrimental to someone that relies on that signal, such as a person using GPS for navigation. NRL researchers have recently predicted that such effects are nearly eliminated for SWCNT-based nanoelectronics due to their small size, low density, and inherent isolation from neighboring SWCNTs in a device.

The cumulative effects in traditional electronics results from trapped charges in the oxides of the devices, including the gate oxide and those used to isolate adjacent devices, the latter being primary source of radiation-induced performance degradation in state-of-the-art complementary metal-oxide semiconductor (CMOS) devices. The effect is manifested as a shift in the voltage needed to turn the transistor on or off. This initially results in power leakage, but can eventually cause failure of the entire circuit.

By developing a SWCNT structure with a thin gate oxide made from thin silicon oxynitride, NRL researchers recently demonstrated SWCNT transistors that do not suffer from such radiation-induced performance changes. This hardened dielectric material and naturally isolated one-dimensional SWCNT structure makes them extremely radiation tolerant.

The ability for SWCNT-based transistors to be both tolerant to transient and cumulative effects potentially enables future space electronics with less redundancy and error-correction circuitry, while maintaining the same quality of fidelity. This reduction in overhead alone would greatly reduce power and improve performance over existing space-electronic systems even if the SWCNT-based transistors operate at the same speed as current technologies. Even greater benefits are foreseeable in the future, once devices are developed that exceed the performance of silicon-based transistors.


Story Source:

The above story is based on materials provided by Naval Research Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

Naval Research Laboratory. "High durability of nanotube transistors in harsh space environment demonstrated." ScienceDaily. ScienceDaily, 18 September 2012. <www.sciencedaily.com/releases/2012/09/120918113419.htm>.
Naval Research Laboratory. (2012, September 18). High durability of nanotube transistors in harsh space environment demonstrated. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2012/09/120918113419.htm
Naval Research Laboratory. "High durability of nanotube transistors in harsh space environment demonstrated." ScienceDaily. www.sciencedaily.com/releases/2012/09/120918113419.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Newsy (Oct. 21, 2014) If you've ever watched "Back to the Future Part II" and wanted to get your hands on a hoverboard, well, you might soon be in luck. Video provided by Newsy
Powered by NewsLook.com
Robots to Fly Planes Where Humans Can't

Robots to Fly Planes Where Humans Can't

Reuters - Innovations Video Online (Oct. 21, 2014) Researchers in South Korea are developing a robotic pilot that could potentially replace humans in the cockpit. Unlike drones and autopilot programs which are configured for specific aircraft, the robots' humanoid design will allow it to fly any type of plane with no additional sensors. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Portable Breathalyzer Gets You Home Safely

Portable Breathalyzer Gets You Home Safely

Buzz60 (Oct. 21, 2014) Breeze, a portable breathalyzer, gets you home safely by instantly showing your blood alcohol content, and with one tap, lets you call an Uber, a cab or a friend from your contact list to pick you up. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
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