Navigation Links
Nanowires key to future transistors, electronics
Date:11/26/2009

WEST LAFAYETTE, Ind. - A new generation of ultrasmall transistors and more powerful computer chips using tiny structures called semiconducting nanowires are closer to reality after a key discovery by researchers at IBM, Purdue University and the University of California at Los Angeles.

The researchers have learned how to create nanowires with layers of different materials that are sharply defined at the atomic level, which is a critical requirement for making efficient transistors out of the structures.

"Having sharply defined layers of materials enables you to improve and control the flow of electrons and to switch this flow on and off," said Eric Stach, an associate professor of materials engineering at Purdue.

Electronic devices are often made of "heterostructures," meaning they contain sharply defined layers of different semiconducting materials, such as silicon and germanium. Until now, however, researchers have been unable to produce nanowires with sharply defined silicon and germanium layers. Instead, this transition from one layer to the next has been too gradual for the devices to perform optimally as transistors.

The new findings point to a method for creating nanowire transistors.

The findings are detailed in a research paper appearing Friday (Nov. 27) in the journal Science. The paper was written by Purdue postdoctoral researcher Cheng-Yen Wen, Stach, IBM materials scientists Frances Ross, Jerry Tersoff and Mark Reuter at the Thomas J. Watson Research Center in Yorktown Heights, N.Y, and Suneel Kodambaka, an assistant professor at UCLA's Department of Materials Science and Engineering.

Whereas conventional transistors are made on flat, horizontal pieces of silicon, the silicon nanowires are "grown" vertically. Because of this vertical structure, they have a smaller footprint, which could make it possible to fit more transistors on an integrated circuit, or chip, Stach said.

"But first we need to learn how to manufacture nanowires to exacting standards before industry can start using them to produce transistors," he said.

Nanowires might enable engineers to solve a problem threatening to derail the electronics industry. New technologies will be needed for industry to maintain Moore's law, an unofficial rule stating that the number of transistors on a computer chip doubles about every 18 months, resulting in rapid progress in computers and telecommunications. Doubling the number of devices that can fit on a computer chip translates into a similar increase in performance. However, it is becoming increasingly difficult to continue shrinking electronic devices made of conventional silicon-based semiconductors.

"In something like five to, at most, 10 years, silicon transistor dimensions will have been scaled to their limit," Stach said.

Transistors made of nanowires represent one potential way to continue the tradition of Moore's law.

The researchers used an instrument called a transmission electron microscope to observe the nanowire formation. Tiny particles of a gold-aluminum alloy were first heated and melted inside a vacuum chamber, and then silicon gas was introduced into the chamber. As the melted gold-aluminum bead absorbed the silicon, it became "supersaturated" with silicon, causing the silicon to precipitate and form wires. Each growing wire was topped with a liquid bead of gold-aluminum so that the structure resembled a mushroom.

Then, the researchers reduced the temperature inside the chamber enough to cause the gold-aluminum cap to solidify, allowing germanium to be deposited onto the silicon precisely and making it possible to create a heterostructure of silicon and germanium.

The cycle could be repeated, switching the gases from germanium to silicon as desired to make specific types of heterostructures, Stach said.

Having a heterostructure makes it possible to create a germanium "gate" in each transistor, which enables devices to switch on and off.


'/>"/>

Contact: Emil Venere
venere@purdue.edu
765-494-4709
Purdue University
Source:Eurekalert  

Related biology technology :

1. Understanding mechanical properties of silicon nanowires paves way for nanodevices
2. Penn study: Transforming nanowires into nano-tools using cation exchange reactions
3. Harvard scientists bend nanowires into 2-D and 3-D structures
4. Evidence of macroscopic quantum tunneling detected in nanowires
5. Self-assembled nanowires could make chips smaller and faster
6. Researchers peer into nanowires to measure dopant properties
7. Strong elasticity size effects in ZnO nanowires
8. Nanowires may boost solar cell efficiency, UC San Diego engineers say
9. Spiraling nanotrees offer new twist on growth of nanowires
10. Engineers make first active matrix display using nanowires
11. Carbon nanotubes outperform copper nanowires as interconnects
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Nanowires key to future transistors, electronics
(Date:10/10/2017)... ... ... San Diego-based team building and cooking events company, Lajollacooks4u, has unveiled a ... new look is part of a transformation to increase awareness, appeal to new markets ... It will also expand its service offering from its signature gourmet cooking classes and ...
(Date:10/10/2017)... 10, 2017 SomaGenics announced the receipt of ... develop RealSeq®-SC (Single Cell), expected to be the first ... (including microRNAs) from single cells using NGS methods. The ... to accelerate development of approaches to analyze the heterogeneity ... "New techniques for measuring levels of mRNAs in individual ...
(Date:10/9/2017)... ... 2017 , ... At its national board meeting in North Carolina, ARCS® ... Departments of Physics and Astronomy, has been selected for membership in ARCS Alumni ... the 2015 Breakthrough Prize in Fundamental physics for the discovery of the accelerating expansion ...
(Date:10/7/2017)... Mass. , Oct. 6, 2017  The ... work of three scientists, Jacques Dubochet, Joachim ... breakthrough developments in cryo-electron microscopy (cryo-EM) ... technology within the structural biology community. The winners ... Scientists can now routinely produce highly resolved, three-dimensional ...
Breaking Biology Technology:
(Date:10/4/2017)... Oct. 4, 2017  GCE Solutions, a global clinical research organization ... document anonymization solution on October 4, 2017. Shadow is designed to ... comply with policy 0070 of the European Medicines Agency (EMA) in ... ... ...
(Date:8/15/2017)... 15 2017   ivWatch LLC , a medical device company ... today announced receipt of its ISO 13485 Certification, the global standard ... Organization for Standardization (ISO®). ... Model 400 Continuous Monitoring device for the early detection of IV ... "This is an important milestone for ...
(Date:6/30/2017)... June 30, 2017 Today, American Trucking ... supplier of face and eye tracking software, became ... provider program. "Artificial intelligence and ... to monitor a driver,s attentiveness levels while on ... able to detect fatigue and prevent potential accidents, ...
Breaking Biology News(10 mins):