Recent history is marked by great technological developments which have received an enormous boost from the progress of microelectronics: large mainframe computers at the beginning of the 1970s, personal computers in the office or home during the 1980s, communications, and lastly “convergent” systems which bring calculation functions, communications and multimedia capacity together in a single device. Recently, microelectronics have irrupted into applications where they were unthinkable until only a short while ago, creating enormous potential. In the health sector, for example, new chips are appearing which are able to diagnose diseases rapidly by analysing the DNA of pathogens.
Moore and beyond
The current view is that growth in microelectronics technology follows Moore's law, a theory put forward some years ago - thanks to a bit of skill and a bit of luck - by one of the founders of Intel. Essentially it states that the number of transistors in a semiconductor circuit doubles every 18 months. In reality Moore's law does not describe technological progress in an entirely satisfactory way. The number of transistors has doubled about every 24 months. However increasingly compact integrated systems with a growing number of active elements have one large drawback: they consume more and more energy. A group of experts at Intel itself have calculated that if technology continues to advance as foreseen by Moore's law, we will shortly have devices with a consumed energy density comparable to a nuclear reactor or - in a few years time - even the surface of the sun. We clearly cannot keep on down this road!
The technological roadmap is not enough
The assumption on which Moore’s law is based is the possibility to squeeze an ever increasing number of transistors onto the same silicon surface. In jargon, this is called the technological roadmap: it is an almost mechanical evolution. The number of transistors increases, therefore the number of functions increases, so chips become more and more powerful (and consume more and more power). All very useful, especially for calculation applications, but the real world is not made of calculation alone. Of course the heart of any system behaves like a human brain: it manages and performs calculations. However a brain is not enough. You need muscles, arms, legs and eyes: you need sensors to analyse external reality and actuators to interact with it. When it is necessary to process analogue signals, generate the power to drive actuators (valves, solenoids, etc.) or produce music at very high volume, reducing the dimensions of silicon geometries is not much use, and “traditional” CMOSs start to show their limits.
Mixed technologies: the revenge of lateral thinking
Electronic sensors and actuators need power technologies, or radiofrequencies to communicate remotely, or fluidics to analyse and manage fluids, etc. These are all areas where progress is not and cannot be governed by Moore's law.
In a complete system inserted efficiently into the surrounding environment, the volume and importance of the "brain" increases (the computing power), but the need to interact with the outside grows exponentially (fig. 1). Elements whose development is dictated by Moore's law need to coexist with circuit blocks which are “more than Moore” and whose development does not depend on the almost mechanical progress of lithographic processes. They are instead the result of the designers' true capacity to invent and innovate, to apply so-called "lateral thinking” to come up with brilliant solutions for unusual applications (fig. 2).
“Cluster” inventions, which depart from the norms
You will not win a Nobel prize for reducing CMOS geometries, but you may do for identifying and implementing “clusters” of original inventions with direct impact on everyday life, which use old and consolidated technologies. In the health service, for example, ever better knowledge of the map of the human genome and DNA go arm in arm with electronics, fluidics and micromechanical applications integrated on silicon to give rise to a “cluster” of inventions which improve the quality of life (fig. 3). Something similar will take place in other fields too, which perhaps have not yet been identified.
In this scenario, Europe has a lot of cards up its sleeve. It is moving with great energy and has enormous potential know-how and intellectual resources to exploit, great schools and universities, and brilliant young talents, and in some cases it has imposed its leadership.
Europe can play a leading role
STMicroelectronics, for example, is unquestionably the leader in “smart power”. In its laboratories in Cornaredo, near Milan, Italy, digital calculation, analogue and power components have been integrated into a single silicon device. Muscles and brains together to create smart power: a technology which has given excellent results on the market. Overall sales have now by far exceeded a billion dollars a year, and this was achieved without using the most daring lithographic techniques. We have instead used a clever combination of very sophisticated technological "stratagems" which however do not distort the basic production processes and mainly use consolidated and standard techniques to create really innovative products. These include high density or high power chips which control car engines and braking systems, or high voltage devices for supplying power, driving plasma flat screens or lighting engineering.
Silicon is not just a semiconductor
STMicroelectronics has been able to exploit its deep knowledge of silicon, combined with a low-cost mass production capability, to build “mixed” microelectromechanical systems: MEMS. These are circuits which integrate the silicon needed to measure physical quantities (acceleration, pressure, movement, etc.) and process the relevant electrical signals into a single package. This is yet another innovative way of using a well known material, silicon, and offer totally new solutions. One of ST's most successful MEMS to date is a triaxial accelerometer used by Nintendo for its new generation video games. The circuit was conceived, designed and brought to industrial levels in the Cornaredo laboratory. It can be used to make an absolutely innovative interface. The player "grips" a small remote control which he can wield like a sword or swing like a tennis racket. The triaxial accelerometer detects the movement and angle of the hand and arm and puts the player in the middle of the action. Accelerometers can also have less fun uses. In cars they detect imminent collisions or the excessive roll which precedes overturning, and are therefore indispensable active safety devices. Fitted to PCs, accelerometers can detect the devastating fall of a laptop onto the floor. In this case, the hard disk heads are parked in a safe position.
MEMS: the limit is the designer's imagination
A MEMS component could be used to replace cell phone microphones, thus simplifying assembly with considerable cost savings. MEMS technology could also contribute towards making extremely compact mass storage consisting of very thin “sheets” of material where the sequence of bits is represented by a set of micro-holes. This application would allow tens of Gbytes of memory to be integrated into a mobile phone. Micro-motors would need to be built to “read” the micro-holes with molecular or even atomic-precision. However silicon manufacturers are not panicking: some examples of these technologies are already operating in the most advanced laboratories, one of them is the famous IBM Millepede (fig. 4).
A device capable of digital calculations and fluid management may also be used for DNA analysis. ST has created a true integrated chemistry laboratory on silicon. This device can rapidly diagnose diseases by analysing the DNA of pathogens. It is a low-cost “disposable” system with almost immediate response times, useful at border posts to detect carriers of dangerous diseases, such as bird flu, for example (fig. 5).
From the roadmap to creativity
Apply lateral thinking and think non-conventionally. It may just mean putting several silicon chips into a single package, rather than increasing the number of functions integrated into a single chip. The final result is again an increase in compactness, but with a few benefits: different chips may be made using different technologies optimized for different functions. ST is already looking into how to “pile” up to eight chips into a single package. The future of technology is primarily knowing how to use your mind to single out new applications and new uses for “old” and reliable competitive manufacturing techniques. It means tackling the enormous potential which also stems from the combination of different specialist areas such as medicine, biology and electronics. In the future, this combination could improve the quality of life and have enormous economic repercussions.
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