Featured Research

from universities, journals, and other organizations

New Theory Explains Why Critical Component In Transistors Wears Down, May Lead To More Reliable Electronic Devices

Date:
December 8, 1998
Source:
Bell Labs - Lucent Technologies
Summary:
Bell Labs researchers have created and proven a theory that explains why gate oxides -- a critical component in transistors and flash memory applications -- wear down and eventually become unreliable. The research findings could help the chip industry find ways to improve the reliability of electronic devices.

SAN FRANCISCO -- Bell Labs researchers have created and proven a theory that explains why gate oxides -- a critical component in transistors and flash memory applications -- wear down and eventually become unreliable.

The research findings, which include novel simulation software, could help Lucent's Microelectronics Group and the rest of the semiconductor chip industry find ways to maintain the reliability of electronic devices, even as gate oxide layers continue to be made thinner and thinner as chips shrink in size. The researchers presented their findings Dec. 7 at the IEEE International Electron Devices Meeting.

In a transistor, the thin gate oxide layer -- usually silicon dioxide -- lies between the gate electrode, which turns current flow on and off, and the channel through which this current flows. The gate oxide layer, in essence, acts as an insulator, protecting the channel from the gate electrode and preventing a short circuit.

By reducing the thickness of the gate oxide layer, it is possible to increase the transistor's switching speed. That's because the electrode is even closer to the channel, thereby inducing a larger current to flow through the transistor. However, the thinner oxide layers degrade at lower voltages, and their wear-out behavior is more difficult to understand than the behavior of thicker oxides. As a result, it is quite difficult to predict both the lifetime of a thin gate oxide and which voltages are safe for transistor operation.

To better understand these issues, Bell Labs researchers Jeff Bude, Bonnie Weir and Paul Silverman studied gate oxide thicknesses -- less than 20 atoms thick -- in today's 0.25-micron transistors. Previous theories of oxide damage suggested a weak flow of electrons through the oxide layer could knock lower energy electrons out of their places, leaving behind "hot" holes -- regions without electrons -- which then could penetrate the gate oxide and weaken it. However, this theory was insufficient to evaluate thinner oxides and also oxide wear-out at lower voltages.

The three researchers corrected the deficiencies in the standard theory and developed software that simulates the hot hole phenomenon and predicts the exact location and energy of the holes. They then compared the findings with observations of gate oxides that had been damaged, and the two sets of results matched.

"During the design process for gate oxides," Bude said, "the software could predict when the hot-hole phenomenon could pose a problem, and the designers could try a different approach. The software also could predict how much voltage a gate oxide can withstand."

Lucent Technologies, headquartered in Murray Hill, N.J., designs, builds and delivers a wide range of public and private networks, communications systems and software, data networking systems, business telephone systems and microelectronics components. Bell Laboratories is the research and development arm for the company. For more information on Lucent Technologies, visit the company's web site at http://www.lucent.com.


Story Source:

The above story is based on materials provided by Bell Labs - Lucent Technologies. Note: Materials may be edited for content and length.


Cite This Page:

Bell Labs - Lucent Technologies. "New Theory Explains Why Critical Component In Transistors Wears Down, May Lead To More Reliable Electronic Devices." ScienceDaily. ScienceDaily, 8 December 1998. <www.sciencedaily.com/releases/1998/12/981207233515.htm>.
Bell Labs - Lucent Technologies. (1998, December 8). New Theory Explains Why Critical Component In Transistors Wears Down, May Lead To More Reliable Electronic Devices. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/1998/12/981207233515.htm
Bell Labs - Lucent Technologies. "New Theory Explains Why Critical Component In Transistors Wears Down, May Lead To More Reliable Electronic Devices." ScienceDaily. www.sciencedaily.com/releases/1998/12/981207233515.htm (accessed October 1, 2014).

Share This



More Computers & Math News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Microsoft Goes For Familiarity Over Novelty In Windows 10

Microsoft Goes For Familiarity Over Novelty In Windows 10

Newsy (Sep. 30, 2014) At a special event in San Francisco, Microsoft introduced its latest operating system, Windows 10, which combines key features from earlier versions. Video provided by Newsy
Powered by NewsLook.com
French Apple Fans Discover the Apple Watch

French Apple Fans Discover the Apple Watch

AFP (Sep. 30, 2014) Apple fans in France discover the latest toy, the Apple Watch. The watch comes in two sizes and an array of interchangeable, fashionable wrist straps. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Apple Releases 'Shellshock' Fix Despite Few Affected Users

Apple Releases 'Shellshock' Fix Despite Few Affected Users

Newsy (Sep. 29, 2014) Apple released a security fix for the "Shellshock" vulnerability Monday, though it says only "advanced UNIX users" of OS X need it. Video provided by Newsy
Powered by NewsLook.com
Do Video Games Trump Brain Training For Cognitive Boosts?

Do Video Games Trump Brain Training For Cognitive Boosts?

Newsy (Sep. 29, 2014) More and more studies are showing positive benefits to playing video games, but the jury is still out on brain training programs. 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