Vertical transistors: the microchip revolution from IBM and Samsung

New microchips designed with vertical transistors were presented a few weeks ago by IBM and Samsung . The innovation, which for now remains at a theoretical level, would allow, according to the two great IT giants, to revolutionize the use of mobile devices. In fact, from the first estimates, the new structure of the microchips is able to guarantee a considerable saving of electric charge with a consequent increase in battery life . But before we understand the big news, let's take a step back to understand how traditional FETs are made.

From horizontal to vertical FETs

MOSFETs (Metal-oxide-semiconductor Field-effect Transistors) or field-effect transistors have been introduced in the field of electronics since the 1960s . Initially developed by Bell Laboratories, they actually revolutionized computer technology and design. Their structure provides a substrate of doped semiconductor material (such as silicon) on which three terminals are applied: gate, source and drain. The gate is typically made of conductive material, while the source and drain are of doped semiconductor material. Source and drain are doped to the opposite of the substrate: in fact, if the substrate has a pi type doping, two terminals will have n type doping, and vice versa. By applying voltage to the gate it is possible to control the current flowing through the device.

ibm vertical transistor

As can be guessed from the structure of the transistor, the current flows laterally between the source and the drain . The devices can then be placed side by side, placing a gap between them, in order to isolate them. This peculiarity, as we will see, has been exploited by researchers from IBM and Samsung to revolutionize the structure of microchips.

The limits of hardware and Moore's law

The research was dictated by the achievement of a threshold beyond which it is not possible to produce more performing hardware . This limit is well known to experts in the sector under the name of Moore's Law and in these years we are about to reach the fateful threshold, defined years ago by the American engineer.

The production process, in fact, is no longer able to position other transistors in the integrated circuits. The only way to improve the power of a microprocessor is to take advantage of alternative techniques such as parallel computing or software optimizations .

The vertical transistor innovation from IBM and Samsung

The breakthrough was to rethink the layout of the circuitry in the microchips and therefore insert the transistors with the current flowing vertically. The name of this new technology is Vertical Transport Field Effect Transistor (VTFET) precisely by virtue of their configuration rotated by 90 ° compared to traditional ones . In this way, on the one hand it is possible to save space in the configuration of the microchip and on the other hand, increasing the number of transistors will increase its computational power.

The architectural structure of the new VTFET transistors in which it is possible to appreciate their placement which saves space. (Source: IBM)

In addition, they are better insulated and consequently are able to provide higher operating voltages and driving currents. These aspects are particularly relevant from a battery consumption point of view. In fact, by reducing dispersion by about 50%, the new transistors will be less energy-intensive, making the batteries last longer and offering improved performance .

We just have to wait for new results from the already promising laboratory tests for this which could become the revolution in processor architectures.

The article Vertical transistor: the microchip revolution from IBM and Samsung comes from Tech CuE | Close-up Engineering .