3-in-1 device offers alternative to Moore's law

June 14, 2017 by Lisa Zyga feature
Illustration of the reconfigurable device with three buried gates, which can be used to create n- or p-type regions in a single semiconductor flake. Credit: Dhakras et al. ©2017 IOP Publishing Ltd

In the semiconductor industry, there is currently one main strategy for improving the speed and efficiency of devices: scale down the device dimensions in order to fit more transistors onto a computer chip, in accordance with Moore's law. However, the number of transistors on a computer chip cannot exponentially increase forever, and this is motivating researchers to look for other ways to improve semiconductor technologies.

In a new study published in Nanotechnology, a team of researchers at SUNY-Polytechnic Institute in Albany, New York, has suggested that combining multiple functions in a single device can improve device functionality and reduce fabrication complexity, thereby providing an alternative to scaling down the device's dimensions as the only method to improve functionality.

To demonstrate, the researchers designed and fabricated a reconfigurable device that can morph into three fundamental semiconductor devices: a p-n diode (which functions as a rectifier, for converting alternating current to direct current), a MOSFET (for switching), and a bipolar junction transistor (or BJT, for current amplification).

"We are able to demonstrate the three most important semiconductor devices (p-n diode, MOSFET, and BJT) using a single reconfigurable device," coauthor Ji Ung Lee at the SUNY-Polytechnic Institute told Phys.org. "While these devices can be fabricated individually in modern semiconductor fabrication facilities, often requiring complex integration schemes if they are to be combined, we can form a single device that can perform the functions of all three devices."

The multifunctional device is made of two-dimensional tungsten diselenide (WSe2), a recently discovered transition metal dichalcogenide semiconductor. This class of materials is promising for electronics applications because the bandgap is tunable by controlling the thickness, and it is a direct bandgap in single layer form. The bandgap is one of the advantages of 2D transition metal dichalcogenides over graphene, which has zero bandgap.

In order to integrate multiple functions into a single device, the researchers developed a new doping technique. Since WSe2 is such a new material, until now there has been a lack of doping techniques. Through doping, the researchers could realize properties such as ambipolar conduction, which is the ability to conduct both electrons and holes under different conditions. The doping technique also means that all three of the functionalities are surface-conducting devices, which offers a single, straightforward way of evaluating their performance.

"Instead of using traditional semiconductor fabrication techniques that can only form fixed devices, we use gates to dope," Lee said. "These gates can dynamically change which carriers (electrons or holes) flow through the semiconductor. This ability to change allows the reconfigurable device to perform multiple functions.

"In addition to implementing these devices, the reconfigurable device can potentially implement certain logic functions more compactly and efficiently. This is because adding gates, as we have done, can save overall area and enable more efficient computing."

In the future, the researchers plan to further investigate the applications of these multifunctional devices.

"We hope to build complex computer circuits with fewer device elements than those using the current process," Lee said. "This will demonstrate the scalability of our device for the post-CMOS era."

Explore further: Team engineers oxide semiconductor just single atom thick

More information: Prathamesh Dhakras, Pratik Agnihotri, and Ji Ung Lee. "Three fundamental devices in one: a reconfigurable multifunctional device in two-dimensional WSe2." Nanotechnology. DOI: 10.1088/1361-6528/aa7350

Related Stories

Team engineers oxide semiconductor just single atom thick

February 8, 2017

A new study, affiliated with UNIST has introduced a novel method for fabrication of world's thinnest oxide semiconductor that is just one atom thick. This may open up new possibilities for thin, transparent, and flexible ...

High-performance MoS2 field-effect transistors

June 13, 2014

A team of researchers from Purdue University, SEMATECH and SUNY College of Nanoscale Science and Engineeringwill present at the 2014 Symposium on VLSI Technology on their work involving high-performance molybdenum disulfide ...

Recommended for you

Engineers create plants that glow

December 13, 2017

Imagine that instead of switching on a lamp when it gets dark, you could read by the light of a glowing plant on your desk.

Faster, more accurate cancer detection using nanoparticles

December 12, 2017

Using light-emitting nanoparticles, Rutgers University-New Brunswick scientists have invented a highly effective method to detect tiny tumors and track their spread, potentially leading to earlier cancer detection and more ...

5 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

AlmostClever
1 / 5 (1) Jun 14, 2017
Like neuronal dendrites' having more potential than previously thought, as well as newly realized geometrical, dynamic, recyclable, neuronal (soft) associations, replicating nature's inspiration is an accomplishment indeed.

What's next?

Maybe the construct of intent. The how and why influence enlists underlying capabilities.
Eikka
1 / 5 (2) Jun 14, 2017
In the semiconductor industry, there is currently one main strategy for improving the speed and efficiency of devices: scale down the device dimensions in order to fit more transistors onto a computer chip, in accordance with Moore's law.


Nope. Moore's law isn't about speed or efficiency, but about the number of transistors at the lowest price point per transistor. Scaling down doesn't necessarily bring cost advantges, so simply fitting more transistors per square inch doesn't follow Moore's law.

Again they get it wrong.
carbon_unit
5 / 5 (2) Jun 14, 2017
Not sure I see the point of this. In situations where Moore's law matters (high density memory/processor logic), one generally has massive arrays of the same kind of component and they are usually dedicated, not programmable. If these things could productively do useful things simultaneously, that would be something, but they are one function at a time. Perhaps one could make some sort of Read Only Memory/FLASH-like memory out of them by programming locations to be a transistor or diode, but there's unlikely to be a density gain by doing that. This could be a significant advance in programmable arrays, but I don't see it helping much for conventional memory and logic.
idjyit
not rated yet Jun 15, 2017
Would be useful for integrating Quantum and traditional circuitry
Eikka
not rated yet Jun 15, 2017
In situations where Moore's law matters (high density memory/processor logic), one generally has massive arrays of the same kind of component and they are usually dedicated, not programmable.


So then build reconfigurable CPUS where the allocation of components to cache vs. FPUs can be changed at runtime, to meet the size of the problem at hand.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.