Why ASML’s new chip-making machine is a scientific marvel | Explained Premium

Semiconductor lithography machines by ASML revolutionize computing with extreme precision, pushing boundaries of technology and innovation.

Computers denote data in bits – the famous 0s and 1s – using semiconductors. These are small physical devices that store these values and perform mathematical operations on them. The sum of all these operations is what allows the computer to compute.

We have powerful computers almost everywhere around us thanks to a technology called semiconductor lithography – the science of printing intricate circuits with extreme precision.

There are machines that automate this process, at a cost of anywhere between Rs 800 crore and Rs 1,600 crore. Only one company, ASML, headquartered in the Netherlands, makes them, giving it an absolute monopoly in a market worth $125 billion and rendering it the technology company with the highest market value in Europe.

In February, ASML unveiled its new ‘High NA EUV’ machine. It costs $350 million (Rs 2,900 crore) apiece and is as big as a double decker bus. Industry analysts say the machine ups ASML’s competition with Intel in the market for the most advanced semiconductors, to power the next generation of computers and smartphones.

This machine uses extreme ultraviolet (EUV) photolithography, a next-generation technology, to make the semiconductors. Here, simply speaking, the mould of the circuits of a transistor – a type of semiconductor – are transferred to a silicon wafer coated with a light-sensitive material called a photoresist. When light is shined on the photoresist, the mould solidifies and its gaps can be filled with wires to form the transistor.

The smallest feature size that can be moulded on the silicon wafer is governed by a physics principle called the Rayleigh scattering criterion. According to this criterion, the size of the feature to be projected on the wafer is proportional to the wavelength of light used and inversely proportional to the aperture of the lens that collects light before projecting it onto the wafer.

The proportionality with the wavelength of light includes a factor called ‘k’. Its value depends on many factors, including the operating temperature and the chemical properties of the photoresist, but has a maximum value of 0.25. In the inverse proportionality, the aperture indicates the amount of light that can be collected and focused on the wafer: the greater the aperture, the smaller the feature size.