Now scientists have succeeded in creating near-atomically flat silicon, of the orientation used by the electronics industry, in a room temperature reaction. The flat silicon might one day serve as the base for new biological and chemical sensors. The researchers will present their work at the AVS 59th International Symposium and Exhibition, held Oct. 28 – Nov. 2 in Tampa, Fla.
“In essence, we have made perfect silicon surfaces in a beaker,” says team leader Melissa Hines, a chemist at Cornell University. Researchers had made perfectly flat silicon before, but the prior work focused on silicon surfaces cut along a plane of the crystal that is not used in the electronics industry. Hines’ team has created the flat surfaces along the industry-standard crystal orientation.
The creation of the team’s first near-atomically flat surface came as a bit of a surprise. It was widely believed that the dissolving process the team used to clean the silicon left rough, bumpy surfaces. Hines was working on a review paper and had asked one of her graduate students to take an picture of the surface using an instrument called a scanning tunneling microscope (STM) that can image surfaces to atomic-level detail. “When we looked at the surface, we unexpectedly realized, ‘Hey, this actually looks very flat,’” Hines says.
The microscope images showed a surface with alternating single-atom-wide rows. Using the additional tools of computer simulations and infrared spectroscopy the researchers determined that the silicon atoms in the rows were bonded to hydrogen atoms that acted like a wax, preventing the surface from further reacting once it was set out in the air. “What that means is that if you take this perfectly flat surface, pull it out of the aqueous reactants, and rinse it off, you can leave it lying around in room air on the order of 10-20 minutes without it starting to react,” says Hines. “If you had told me as a graduate student that you could have a clean surface that could just hang out in air for 10 minutes, I would have thought you were crazy.”
The team believes that part of the reason their silicon surfaces are so flat is that they dip the wafers in and out of solution approximately every 15 seconds, preventing bubbles from the reaction from building up and causing uneven etching. However, they also credit the STM images for helping them to realize just how flat the surfaces were. The team built off the information from the images by using computer simulations and other tools to reveal the exact chemical reaction steps that took place in solution. “Experimentally, this is very simple experiment: you take a piece of silicon, you swirl it in a beaker with solution, and then you pull it out and look at it. To be honest, there is no reason to think that Bell Labs did not make a surface as good as ours twenty years ago, but they did not look at it with STM, so they did not know,” says Hines.
Hines’ team is now working on adding molecules to the atomically smooth, hydrogen-terminated silicon surface in the hopes of building new chemical or biological sensors. “At this point, I can’t tell you exactly how we will accomplish this, but we have promising results and hope to be able to report more soon,” says Hines.
MORE INFORMATION ABOUT THE AVS 59th INTERNATIONAL SYMPOSIUM & EXHIBITION
The Tampa Convention Center is located along the Riverwalk in the heart of downtown Tampa at 333 S. Franklin St., Tampa, Florida, 33602.
USEFUL LINKS:Main meeting website:
To register, please contact:Della Miller, AVS
Della Miller | Newswise Science News
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences