The first generation of CMOS (complementary metal-oxide semiconductor) chips were based on a design process with lithographic features defining regions inside the transistors of 10 micrometres or more. The chips in most products in use today have features more than a hundred times smaller – just 65 nanometres (nm) or 90nm, approximately 1,000 times less than the width of a human hair. That may be small, but in the competitive semiconductor industry, where size is of high importance, it is not small enough.
A reduction in minimum feature size means more transistors per chip, more transistors means more computing power, and more power means electronic systems – mobile phones, PCs, satellites, vehicles, etc. – will gain in functionality and performance. And, because the processed silicon wafers out of which chips are made are expensive (setting up a factory to produce them costs €3 billion) using less of them to do more means the trend toward such devices becoming cheaper can continue.
“The semiconductor industry is in the business of selling square millimetres of silicon. So, by cramming more transistors into a chip you’re delivering more capacity, more functionality and more computing power for the same price. It’s why things like mobile phones, LCD TVs and DVD players are coming down in price,” notes Gilles Thomas, the director of R&D Cooperative Programs at STMicroelectronics in Crolles, France, the world’s fifth biggest semiconductor manufacturer and Europe’s largest semiconductor supplier.Taking the ‘O’ out of CMOS
A follow-up project, called Pullnano and coordinated by Thomas, is currently working on developing nodes as small as 32nm and even 22nm. At that diminutive size, semiconductor manufacturing is continuing to test Moore’s Law, an assumption spelled out by Intel co-founder Gordon E Moore, in 1965, predicting that the number of transistors that can be cost-effectively placed on a chip will double approximately every two years.
“The work of NanoCMOS and Pullnano has moved in that direction, although there is probably 12 or 15 more years to go before we hit a practical and economical limit on how small the nodes can become,” Thomas explains.
At the 32nm scale, in particular, quantum mechanical effects come into play in a big way. One major problem the Pullnano researchers have solved is reducing current leakage at the logic gate by using a hafnium compound-based insulator with higher dielectric strength than traditional silicon dioxide.
“We’ve achieved a 100-fold reduction in gate leakage,” Thomas says, noting that it is the first time the oxide – the ’O’ in CMOS – has been replaced with a different material.Semiconductor makers’ “million-dollar question”
“At that point it would not be economical or practical to go smaller, even though, in theory, it would be possible,” he says.
Even so, there is still some time before that point is reached. STMicroelectronics is due to start sampling the 45nm node semiconductors that the NanoCMOS project helped develop from next year, with a view to placing electronic systems using them in consumers’ hands by 2009.
By 2011, the Switzerland-headquartered company expects to start commercialising the 32nm node semiconductors being developed in the Pullnano initiative, with a view to developing a commercially viable 22nm process a couple of years after that.
“The 45nm process has already been validated through the production of an SRAM [static random access memory] chip, which we use to benchmark the performance of each generation. We will do the same with the 32nm process,” Thomas says.
NanoCMOS, which involved 20 partners, and Pullnano, which involves 38 partners, have helped give Europe an edge in semiconductor manufacturing, suggests Thomas, although he notes that the highly competitive sector remains dominated by American and Asian giants such as Intel and Samsung. Nonetheless, there is plenty of room for future growth, even as chips become cheaper.
Consumers will be the biggest beneficiary of the continuation of this miniaturisation trend. The economies of scale created within the $260 billion (+/- €183 billion) semiconductor industry have put electronics within the reach of the masses as the cost per transistor has fallen 2,500 times over the last 25 years. This is thanks to shrinking feature sizes and to increases in transistor manufacturing capacity by a factor of some 30,000.
“Just look at computer memory, in the early 1970s one megabyte cost more than a house, now it costs less than a piece of candy,” Thomas notes.
Christian Nielsen | alfa
Stable magnetic bit of three atoms
21.09.2017 | Sonderforschungsbereich 668
Drones can almost see in the dark
20.09.2017 | Universität Zürich
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
25.09.2017 | Power and Electrical Engineering
25.09.2017 | Health and Medicine
25.09.2017 | Physics and Astronomy