Manufacturing small components under 10 nm by electron microscopy

Physicists at the University of Pennsylvania (USA), Michael Fischbein and Marija Drndic, have invented an effective technique that enables the fabrication of complex nanostructures with just an electron microscope. transmitted.

This method produces much higher resolution than other nano-device fabrication methods, which can be used in nano-electronics, etc., or manipulate particles on a chip. The group has just published results in NanoLetters .

In science and nanotechnology, creating perfect, high-quality nanostructures plays an extremely important role. Although there have been many different achievements in creating nanostructures, the fabrication and manipulation of small components is still difficult. For example, the current popular technology is limited to e-beam lithography (EBL) when the component size is reduced to a few tens of nanometers due to many limitations of contrast coating as well as sports. Working on electron beams. Moreover, the creation of small parts under 10 nm using top-down method is even more difficult.

Figure 1. Principle diagram of manufacturing process (According to NanoLetter 7 (2007) 1329).

Recently, two scientists from the University of Pennsylvania (USA), Michael Fischbein and Marija Drndic, have published the results that can use Transmission Electron Microscope (TEM) to prepare create small metal parts under 10 nm with high precision .

Initially, the team that created the components by traditional methods is electron beam lithography, which is the metal component on a 100 nm SiN dielectric membrane (SiN membrane is the base layer, but will help the electron beam. easily penetrated, while reducing electronic backscattering during photolithography.

Next, the system is placed in the TEM and will continue the " sculpting " process with a narrow electron beam transmitted by the electron microscope.

"Normally, when the electron beam is used to create him at a very high magnification, we can observe that this" sculpture "process takes place in real time," explained Fischbein. In fact, this is an in situ process that allows to control the process of creating components with the ultimate smoothness and perfect finish. The specific shapes here are that the researchers fabricated nanowires, nano slots, nano rings, and polar parts. Essentially the electron beam will evaporate unnecessary details (because TEM's electron beam has a very high energy) and create an image when transmitted to observe in real time.

Finally, another advantage of the technique (called " abrasive etching ") is that it can work without contrast materials or liff-off steps as optical etching techniques system.

Figure 2. Some images of successful manufacturing details (According to NanoLetter 7 (2007) 1329).

All structures published in this work are hand-made, meaning scientists move the beam while observing the wear over time. According to the research team, if this process is connected to a computer (controlling electron beam operations as in EBL technology), this process can be performed even with much higher accuracy and progress. operating on larger areas.

"This technique can be used in many areas of science and nanotechnology (nanoelectronics, nanofluids, plasmonics .)" - Fischbein told Nanotechweb.org reporter - "An interesting point in the The recently published work is to create nano-slot components and holes for biochip (DNA sequencing) ". Details of this project can be found in NanoLetters number 7, 2007.

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According to NanotechWeb.org & NanoLetters, Vietnamese Physics