Navigation Links
Tiny compound semiconductor transistor could challenge silicon's dominance
Date:12/10/2012

CAMBRIDGE, Mass. -- Silicon's crown is under threat: The semiconductor's days as the king of microchips for computers and smart devices could be numbered, thanks to the development of the smallest transistor ever to be built from a rival material, indium gallium arsenide.

The compound transistor, built by a team in MIT's Microsystems Technology Laboratories, performs well despite being just 22 nanometers (billionths of a meter) in length. This makes it a promising candidate to eventually replace silicon in computing devices, says co-developer Jess del Alamo, the Donner Professor of Science in MIT's Department of Electrical Engineering and Computer Science (EECS), who built the transistor with EECS graduate student Jianqian Lin and Dimitri Antoniadis, the Ray and Maria Stata Professor of Electrical Engineering.

To keep pace with our demand for ever-faster and smarter computing devices, the size of transistors is continually shrinking, allowing increasing numbers of them to be squeezed onto microchips. "The more transistors you can pack on a chip, the more powerful the chip is going to be, and the more functions the chip is going to perform," del Alamo says.

But as silicon transistors are reduced to the nanometer scale, the amount of current that can be produced by the devices is also shrinking, limiting their speed of operation. This has led to fears that Moore's Law the prediction by Intel founder Gordon Moore that the number of transistors on microchips will double every two years could be about to come to an end, del Alamo says.

To keep Moore's Law alive, researchers have for some time been investigating alternatives to silicon, which could potentially produce a larger current even when operating at these smaller scales. One such material is the compound indium gallium arsenide, which is already used in fiber-optic communication and radar technologies, and is known to have extremely good electrical properties, del Alamo says. But despite recent advances in treating the material to allow it to be formed into a transistor in a similar way to silicon, nobody has yet been able to produce devices small enough to be packed in ever-greater numbers into tomorrow's microchips.

Now del Alamo, Antoniadis and Lin have shown it is possible to build a nanometer-sized metal-oxide semiconductor field-effect transistor (MOSFET) the type most commonly used in logic applications such as microprocessors using the material. "We have shown that you can make extremely small indium gallium arsenide MOSFETs with excellent logic characteristics, which promises to take Moore's Law beyond the reach of silicon," del Alamo says.

Transistors consist of three electrodes: the gate, the source and the drain, with the gate controlling the flow of electrons between the other two. Since space in these tiny transistors is so tight, the three electrodes must be placed in extremely close proximity to each other, a level of precision that would be impossible for even sophisticated tools to achieve. Instead, the team allows the gate to "self-align" itself between the other two electrodes.

The researchers first grow a thin layer of the material using molecular beam epitaxy, a process widely used in the semiconductor industry in which evaporated atoms of indium, gallium and arsenic react with each other within a vacuum to form a single-crystal compound. The team then deposits a layer of molybdenum as the source and drain contact metal. They then "draw" an extremely fine pattern onto this substrate using a focused beam of electrons another well-established fabrication technique known as electron beam lithography.

Unwanted areas of material are then etched away and the gate oxide is deposited onto the tiny gap. Finally, evaporated molybdenum is fired at the surface, where it forms the gate, tightly squeezed between the two other electrodes, del Alamo says. "Through a combination of etching and deposition we can get the gate nestled [between the electrodes] with tiny gaps around it," he says.

Although many of the techniques applied by the team are already used in silicon fabrication, they have only rarely been used to make compound semiconductor transistors. This is partly because in applications such as fiber-optic communication, space is less of an issue. "But when you are talking about integrating billions of tiny transistors onto a chip, then we need to completely reformulate the fabrication technology of compound semiconductor transistors to look much more like that of silicon transistors," del Alamo says.

The team presents its work this week at the International Electron Devices Meeting in San Francisco.

Their next step will be to work on further improving the electrical performance and hence the speed of the transistor by eliminating unwanted resistance within the device. Once they have achieved this, they will attempt to further shrink the device, with the ultimate aim of reducing the size of their transistor to below 10 nanometers in gate length.


'/>"/>

Contact: Caroline McCall
cmccall5@mit.edu
Massachusetts Institute of Technology
Source:Eurekalert

Related biology technology :

1. Dual-acting class of antimalarial compounds discovered with potential to prevent and treat malaria
2. Boulder Diagnostics Licenses Novel Rapid Detection Technology for Homocysteine and Related Compounds from Portland State University
3. Chimerix Antiviral Compound, CMX001, Meets CMV Phase 2 Primary Endpoint in Allogeneic Hematopoietic Stem Cell Transplant Recipients
4. Pharma IQs Compound Management Survey Report
5. Novel compound halts tumor spread, improves brain cancer treatment in animal studies
6. Silence Therapeutics Partner, Quark Pharmaceuticals, Extends its Agreement With Pfizer to Develop one of Its Compounds Containing Silences AtuRNAi in a New Indication
7. Palatin Technologies Announces Halting of Phase I Clinical Trial of Obesity Compound in AstraZeneca Research Collaboration
8. Scripps Research Institute scientists find easier way to make new drug compounds
9. Botanical compound could prove crucial to healing influenza
10. Chemical makes blind mice see; compound holds promise for treating humans
11. NSF awards $450,000 to UNH, Conductive Compounds Inc. for solar panel innovation
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/24/2016)... , June 24, 2016 Epic ... sensitively detects cancers susceptible to PARP inhibitors by ... tumor cells (CTCs). The new test has already ... therapeutics in multiple cancer types. Over ... DNA damage response pathways, including PARP, ATM, ATR, ...
(Date:6/24/2016)... ... ... Researchers at the Universita Politecnica delle Marche in Ancona combed medical journal articles ... findings are the subject of a new article on the Surviving Mesothelioma website. ... blood, lung fluid or tissue of mesothelioma patients that can help point doctors to ...
(Date:6/23/2016)... ... June 23, 2016 , ... UAS LifeSciences, one of ... their brand, UP4™ Probiotics, into Target stores nationwide. The company, which has been ... Target to its list of well-respected retailers. This list includes such fine stores ...
(Date:6/23/2016)... 23, 2016 /PRNewswire/ - FACIT has announced the ... biotechnology company, Propellon Therapeutics Inc. ("Propellon" or ... of a portfolio of first-in-class WDR5 inhibitors for ... as WDR5 represent an exciting class of therapies, ... medicine for cancer patients. Substantial advances have been ...
Breaking Biology Technology:
(Date:4/28/2016)... First quarter 2016:   , Revenues amounted ... quarter of 2015 The gross margin was 49% (27) ... the operating margin was 40% (-13) Earnings per share ... operations was SEK 249.9 M (21.2) , Outlook   ... M. The operating margin for 2016 is estimated to ...
(Date:4/15/2016)... 2016 Research and Markets has ... Market 2016-2020,"  report to their offering.  , ... ,The global gait biometrics market is expected to ... period 2016-2020. Gait analysis generates multiple ... used to compute factors that are not or ...
(Date:3/29/2016)... , March 29, 2016 LegacyXChange, ... LegacyXChange "LEGX" and SelectaDNA/CSI Protect are pleased to announce ... used in a variety of writing instruments, ensuring athletes ... originally created collectibles from athletes on LegacyXChange will be ... of the DNA. Bill Bollander , ...
Breaking Biology News(10 mins):