Country for PR: Japan
Contributor: Kyodo News JBN
Tuesday, July 26 2022 - 15:00
New TEM Technique Creates 2.8nm Transistor: WPI-MANA
TSUKUBA, Japan, July 26, 2022 /Kyodo JBN-AsiaNet/ --

An international research team at the International Center for Materials 
Nanoarchitectonics (WPI-MANA) has used a transmission electron microscope (TEM) 
to create a 2.8nm transistor consisting of nanochannels embedded in metallic 
carbon nanotubes (CNTs), which exhibits quantum transport at room temperature.


One major aim of nanotechnology research is to control the helical structure of 
a CNT. This structure determines the nanotube's properties, and altering it can 
result in drastic changes, such as turning it from a metal to a semiconductor. 
To achieve this, the focus has been on growing nanotubes to control the 
structure, but this has been very difficult due to their extremely small size, 
only one or two nanometers in diameter.

To address this difficulty, researchers at WPI-MANA have developed a technique 
to precisely manipulate individual CNTs and alter their helical structure 
inside a TEM.

The WPI-MANA team used nanoprobes to apply tension and heat to the CNT. This 
deformed a section of the nanotube, altering its structure and changing it from 
a metal into a semiconductor.

The section of the altered nanotube was very short, and formed a semiconductor 
embedded in a metallic nanotube. The researchers believe this can be used as a 
semiconductor channel, and with the original metallic nanotube as the source 
and drain, the effect is like a molecular transistor embedded inside the 

Dr. Dai-Ming Tang, leading member of the team, said, "This transistor is 
extremely small, only 2.8nm in channel length, shorter than any current 
silicon-based transistors. In fact, this is among the world's smallest 
transistors, and we created it by using our new technique."

Another exciting aspect of this work relates to the behavior of materials on 
such tiny scales. "Because we can make such a very small transistor, other 
effects appear," Dr. Tang said. "For example, we have seen quantum transport at 
room temperature, which is usually observed only at extremely low temperatures."

This could allow the density of transistors on a computer chip to be much 
higher, leading to more powerful and faster electronics.

Research Highlights Vol. 77

MANA Research Highlights

Source: International Center for Materials Nanoarchitectonics (WPI-MANA), 
National Institute for Materials Science (NIMS)