In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.
In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two years. At that time he was regarded as a visionary and pioneering thinker. Today, over 50 years later, we see that the integration density of electronic circuits is still continuing to grow.
Now we can store whole libraries on a chip in our smartphones. That was primarily made possible by revolutionary advances in optical technologies and materials science. And although it’s becoming apparent that there are physical limits, developments are not over yet: scientists at Fraunhofer Institutes in Jena and Aachen are working on the next generation of technology for producing even smaller structures.
New target materials for the 6.7 nm radiation source
A key constraint for the lithographic production of ever smaller structures is the wavelength of the light used. In the 1970s the UV light from a mercury vapor lamp was sufficient; the 1990s saw the emergence of excimer lasers with wavelengths of 193 nm. Today, the semiconductor industry combines these radiation sources with refined methods of optical lithography to manufacture structures as small as 14 nm across.
EUV lithography is a completely new technology that has been developed over the last ten years. It works by using extreme ultraviolet (EUV) radiation at a wavelength of 13.5 nm, which is generated by evaporating a droplet of tin with a high-power laser. The aim is to harness the emitted EUV radiation to produce structures with a size of 10 nm or less.
Having played a leading part in developing EUV technology, scientists at Fraunhofer ILT are now focused on the next step: technology that uses radiation with a wavelength of around 6.7 nm. Instead of tin, they are working with targets made of gadolinium or terbium alloys, as these facilitate correspondingly shorter wavelengths.
Teams from the two Fraunhofer Institutes worked together to develop a new optical system with which to characterize the radiation source. This system enables them to measure factors such as light output to a high degree of spatial and spectral resolution.
The output power of the radiation source is now enough to carry out trials on new mirror coatings or light-sensitive varnishes (resists). Development work on the radiation source is ongoing to achieve the necessary power scaling.
Coating mirrors with atomic precision
Unlike traditional optical lithography, EUV lithography functions use only reflective optics; this means the mirrors have to meet extremely exacting requirements. Nowadays the thickness of mirror coatings must be correct to around 10 picometers. That is less than the diameter of an atom.
It is laborious and expensive to generate EUV radiation, and consequently every percentage point of reflectivity matters. In the case of mirrors for 13 nm radiation, it has been possible to achieve a reflectivity of around 65% using alternating films of silicon and molybdenum. When it comes to mirrors for 6.7 nm radiation, experts from Fraunhofer IOF in Jena have developed special systems using lanthanum and boron compounds. Here, too, they are battling to reach the theoretical limit of around 70%.
Applications in many areas
Today there are already more mobile telephones than human beings on Earth – a fact that was partly made possible by enormous advances in microlithography. This field will continue to be of the utmost importance over the coming years, including for new subject areas such as industry 4.0 or the Internet of Things.
That is why experts from the Fraunhofer Institutes for Applied Optics and Precision Engineering IOF and for Laser Technology ILT have been working since the start of 2014 on developing the basic principles for lithography at even shorter wavelengths. They are collaborating with industrial partners Carl Zeiss SMT and ASML in the “Beyond EUV” project, which runs to the end of 2016, to develop key components for 6.7 nm wavelength technology.
These new lithographic techniques will make it possible to produce structures with a thickness of just a few atoms. There are already lots of ideas for how to use integrated circuits formed from such structures: alongside even higher storage capacity for cloud applications and big data processes, they could also be used for mind-controlled prosthetic limbs or more personalized medicine.
Dr. rer. nat Klaus Bergmann
Group Manager EUV Technology
Telephone +49 241 8906-302
Fraunhofer Institute for Laser Technology ILT, Aachen, Germany
Prof. Dr. Norbert Kaiser
Head of Optical Coatings
Telephone +49 3641 807-321
Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Jena, Germany |
Petra Nolis | Fraunhofer-Institut für Lasertechnik ILT
'Super yeast' has the power to improve economics of biofuels
18.10.2016 | University of Wisconsin-Madison
Engineers reveal fabrication process for revolutionary transparent sensors
14.10.2016 | University of Wisconsin-Madison
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