Stanford Univ. Overcomes Big Hurdles, Makes Efficient Nanotube Circuits
June 15, 2012 8:47 PM
comment(s) - last by
Twisted and misaligned nanotubes long proved the bane of those looking to design CNT circuits, but Stanford researchers have surmounted these obstacles.
(Source: Subhasish Mitra, Stanford University School of Engineering)
Researchers demonstrate CNT circuits built on common manufacturing processes
(CNTs) an unusual tubular allotrope (molecular form) of pure carbon, composed of hexagonal units of SP2 bonded carbon atoms, were first observed in 1991 when studying scorched carbon soot from researchers trying to use high current discharge to form fullerenes. Since then, interest in the tiny carbon "straws" has exploded and the allotrope has become an almost wince-worthy buzzword in the U.S. university research community, suggested for use in everything from
I. Overcoming Crippling CNT Flaws
But you get a feeling that the
's nanofabrication lab efforts are the kind of novel research that are not merely looking to ride the buzz, but truly might be on to something great. Led by Professors
H.-S. Philip Wong
, the lab has spearheaded the challenge of producing electronic circuits out of nanotubes.
The lab recent celebrated two key publications -- an invited paper at the
International Electron Devices Meeting
(IEDM) as well as a
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
The honors came thanks to the lab's ability to demonstrate "wafer-scale" digital logic structures built from carbon nanotubes, including "arithmetic circuits and sequential storage, as well as the first monolithic three-dimensional integrated circuits with extreme levels of integration."
Stanford researchers have demonstrated the most robust and efficient CNT circuits to date via developing processes to eliminate or ignore defects. [Image Source: Stanford Engineering]
Carbon nanotubes have many desirable traits that could make for better computer chips someday. They are super-strong and highly efficient when acting as conductors. Yet they can be made to act as semiconductors, allowing them to be used in advanced transistor designs.
However, making such carbon nanotube circuits is a tall task. That's why the new Stanford breakthroughs are so impressive claims
Carnegie Mellon University
, who comments, "The first CNTs wowed the research community with their exceptional electrical, thermal and mechanical properties over a decade ago, but this recent work at Stanford has provided the first glimpse of their viability to complement silicon CMOS transistors."
Using specialized production tricks the Stanford team developed ways to "ignore" two common kinds of flaws in nanotube designs -- misaligned and mis-positioned CNTs. They also developed processes to screen out yet another kind of undesirable CNTs that sabotaged past designs' efficiency -- metallic CNTs (only the semiconducting CNTs are desired for circuit elements).
II. Nearly Ready for Action in VLSI Circuits
Despite all the complexity in terms of eliminating or negating the effects of "bad" kinds of CNTs, the researchers were still able to adhere to standard semiconductor fabrication techniques, making the process applicable to very large scale integration (VLSI) -- the fundamental process used to design monolithic modern computer circuits such as central processing units (CPUs) and graphics processing units (GPUs).
Betsy Weitzman of the
Focus Center Research Program
Semiconductor Research Corporation
, a North Carolina semiconductor development nonprofit, comments, "This transformative research is made all the more promising by the fact that it can co-exist with today’s mainstream silicon technologies, and leverage today’s manufacturing and system design infrastructure, providing the critical feature of economic viability."
The Stanford CNT research team poses in their "bunny suits". [Image Source: Subhasish Mitra]
Sachin S. Sapatnekar, Editor-in-Chief, IEEE Transactions on CAD praises the Stanford team's hard work and persistence in overcoming performance hurdles. He remarks, "Many researchers assumed that the way to live with imperfections in CNT manufacturing was through expensive fault-tolerance techniques. Through clever insights, Mitra and Wong have shown otherwise. Their inexpensive and practical methods can significantly improve CNT circuit robustness, and go a long way toward making CNT circuits viable."
CNTs are currently competing with alternative materials
for a place in low-power super-fast circuits of the future. In future desktops and servers, such circuits will likely be complemented by other novel designs such as
(particularly useful in solving certain kinds of problems), memristor storage, or even
IEEE Transactions on CAD
This article is over a month old, voting and posting comments is disabled
6/16/2012 3:20:26 PM
It looks like the scale of the image: the white bar under the text is 20um long.
6/16/2012 6:51:57 PM
It doesn't make sense that the 20um bar is the same size in the lower blowup photo.
6/16/2012 9:46:04 PM
Good catch. I was able to find their paper through my university. The scale on the zoomed out image is correct. The scale on the zoomed in imaged should read 2 microns.
6/18/2012 12:18:39 PM
Yup, and it was Stanford's photo with the error, so two cases of indifferent proofreading.
"We’re Apple. We don’t wear suits. We don’t even own suits." -- Apple CEO Steve Jobs
Samsung Researchers Inch Closer to Commercial Graphene Transistors
May 18, 2012, 3:22 PM
New Device Uses Carbon Nanotubes to Catch Tumor Cells Quickly
March 31, 2011, 5:00 PM
Super-Strong Polymer/Carbon Nanotube Blend Outperforms Kevlar
December 6, 2010, 11:32 AM
OSU Ditches "Primitive" Silicon Circuits, Unleashes Organic Spintronics
August 11, 2010, 12:16 PM
Researchers Create Seven Atom Transistor, Working on Quantum Computer
May 24, 2010, 9:15 AM
12/2/2013 Daily Hardware Reviews
December 2, 2013, 3:41 PM
OCZ Goes Bankrupt, SSD Assets are Targeted by Toshiba
December 1, 2013, 9:58 PM
11/27/2013 Daily Hardware Reviews
November 27, 2013, 9:53 AM
11/26/2013 Daily Hardware Reviews
November 26, 2013, 5:42 PM
WD Shows Off New SSD, HDD Dual Drive
November 25, 2013, 10:30 AM
11/25/2013 Daily Hardware Reviews -- Western Digital Black² Dual Drive Edition
November 25, 2013, 9:27 AM
Most Popular Articles
NSA Snares Americans' Porn Viewing Histories in Effort to Target Muslims
December 1, 2013, 9:00 PM
Coalition of 20+ Tech Firms Backs MRAM as Potential DRAM, NAND Replacement
November 29, 2013, 11:59 PM
Fed Up With Cheating OEMs, Microsoft Trolls Chromebooks in New Ad
November 27, 2013, 4:09 PM
Xbox? PCs? Mobile? Microsoft Wants One Windows to Rule Them All
November 25, 2013, 8:21 PM
Seattle Restaurant Bans Google Glass, Tells Wearers to "Just shut up and get out"
November 27, 2013, 10:27 AM
Latest Blog Posts
Global Cyber Espionage Concerns Reveal Growing Cyber Armies
Nov 29, 2013, 11:04 AM
Is The Period Becoming an Expression of Anger?
Nov 26, 2013, 2:02 PM
NSA and Congress -- You Will Never Kill the Constitution, It's an Idea
Nov 10, 2013, 2:00 PM
AT&T Explores $100B+ USD Deal to Acquire Vodafone's European Operations
Nov 4, 2013, 7:34 AM
U.S. Army Developing Cyber, Electronic War Arsenal
Oct 31, 2013, 4:49 PM
More Blog Posts
Copyright 2013 DailyTech LLC. -
Terms, Conditions & Privacy Information