60 years of integrated circuits An integrated circuit is a semiconductor wafer on which thousands or millions of tiny resistors, capacitors, and transistors are fabricated. Sometimes called a chip or microchip. The invention of the integrated circuit made technologies of the Information Age feasible. ICs are now used extensively in all walks of life, from cars to toasters to amusement park rides. Integrated circuits (ICs) are self-contained circuits with many separate components such as transistors, diodes, resistors and capacitors etched into a tiny silicon chip. Related Journals of Integrated circuit Journal of Physical Chemistry & Biophysics, Journal of Electrical & Electronic Systems, Analog Integrated Circuits and Signal Processing, IEEE Radio Frequency Integrated Circuits Symposium, IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, Journal of Integrated Circuits and Systems, Proceedings of the Custom Integrated Circuits Conference. On 12 September 1958, Jack Kilby of Texas Instruments demonstrated a working integrated circuit1. The circuit was a phase-shift oscillator that used transistor, resistor and capacitor elements built from a single piece of germanium; the elements were connected into a circuit with the help of thin gold wires. A few months later, Robert Noyce, working at Fairchild Semiconductor, proposed a monolithic integrated circuit2. This planar design was based on silicon and used lines of aluminium, deposited on the insulating silicon dioxide layer that can form on the surface of silicon wafers, to connect the different circuit elements in the single chip. By 1960, a team of engineers at Fairchild Semiconductor had turned this design into a reality. Electronic components, which had previously been discrete units connected with individual wires, could now be integrated into the same piece of semiconducting material. In the 60 years since Kilby’s initial demonstration, progress in STM8S207C8T6 has been astounding. Noyce would go on to co-found Intel, and just how far the company — and the design of integrated circuits — has come in that time is highlighted in this issue of Nature Electronics. In a News & Views article, Suman Datta of the University of Notre Dame reports on Intel’s 10-nanometre logic technology. With this latest design iteration3, the company has introduced a number of unconventional approaches to improve transistor density and performance, including a technique to reduce the spacing between cells and a method to add gate contacts directly over the active area. As a result, they can deliver around 100 million transistors per square millimetre — a transistor density that is 2.7 times higher than that of their previous 14-nm technology, which was introduced in 2014. At this level of complexity, developments are far from straightforward. Earlier this year, it emerged that Intel have encountered problems in the manufacturing of the 10-nm chips, leading to delays in mass production4; the chips are now expected to ship in volume in 2019. And in the past few weeks, GlobalFoundries announced5 that they would stop development of their 7-nm chips (thought to be comparable to Intel’s 10-nm technology). The continued scaling of silicon complementary metal–oxide–semiconductor (CMOS) technology beyond these levels is also likely to prove increasingly difficult. But, at the same time, the applications of computers are evolving, and demand the processing of ever larger amounts of data. As a result, the search for strategies and materials beyond silicon, which could help create the next generation of devices and integrated circuits, remains vital. Carbon nanotubes are among the contenders fighting for a place in the future of electronics, and in our Reverse Engineering column in this issue, Cees Dekker recounts how the first carbon nanotube transistor was built back in 1998. A related contender in this fight is two-dimensional materials, as well as the vertical stacks of different two-dimensional materials known as van der Waals heterostructures. These materials have been used to build a range of promising devices and some basic circuits — even a microprocessor6. The unique challenges involved in trying to build practical integrated circuits from two-dimensional materials are just starting to be addressed, but innovative ideas are emerging. For example, in an Article in this issue, Moon-Ho Jo and colleagues illustrate how a scanning light probe can be used to write monolithic integrated circuits For ST on two-dimensional molybdenum ditelluride (MoTe2). The researchers — who are based at the Institute for Basic Science in Pohang, Pohang University of Science and Technology, the Korea Institute of Materials Science, and Yonsei University — first pattern gold electrodes onto the MoTe2. Then, by shining the light probe (a visible laser) onto the electrodes, the semiconducting MoTe2 beneath can be converted from an n-type semiconductor to a p-type semiconductor. (With silicon CMOS technology, such doping is typically achieved using ion implantation.) The approach allows the two-dimensional material to be doped precisely and quickly, and Jo and colleagues use it to create arrays of bipolar junction transistors and circular diodes.