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

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

Subject: Science and tech

Section: Awareness in IT &Computer

Semiconductor lithography:

• Computers operate by encoding data into bits, represented by 0s and 1s, through semiconductors. These small devices store data and execute calculations, enabling computing functions.
• The widespread availability of powerful computers is largely due to semiconductor lithography, a technique for crafting detailed circuits with high precision.
• This process is automated by highly expensive machines, costing between Rs 800 crore and Rs 1,600 crore.

High NA EUV machine:

• ASML, a company based in the Netherlands, has a monopoly in this field, producing these machines for a market valued at $125 billion, making it Europe’s most valuable tech company.
• In February, ASML introduced its “High NA EUV” machine, priced at $350 million each and comparable in size to a double-decker bus.
• This machine, utilizing extreme ultraviolet (EUV) photolithography, represents a leap in semiconductor manufacturing technology. It enables the creation of semiconductors by transferring the circuit design of a transistor onto a silicon wafer coated with a light-sensitive substance.
• Exposing this to light solidifies the design, allowing for the addition of wiring to complete the transistor. This innovation puts ASML in direct competition with Intel in the race to supply advanced semiconductors for future computers and smartphones.

What is the Rayleigh scattering criterion?

• The Rayleigh scattering criterion is a principle in physics that dictates the minimum feature size that can be accurately imprinted onto a silicon wafer during the semiconductor manufacturing process.
• This criterion establishes that the size of the feature is directly proportional to the wavelength of the light used and inversely proportional to the lens aperture that directs the light onto the wafer.
• The proportionality to the wavelength includes a variable factor ‘k’, which can reach up to 0.25 and is influenced by factors such as the operating temperature and the chemical properties of the photoresist used.
• The aperture represents the capacity to collect and focus light on the wafer, meaning a larger aperture allows for smaller features.
• To achieve finer details on wafers, engineers have historically focused on utilizing light with shorter wavelengths. For instance, chip manufacturers transitioned from using light with a wavelength of 436 nanometers (nm) about forty years ago to employing extreme-ultraviolet (EUV) light with a wavelength of 13.5 nm in modern equipment. Before the adoption of EUV technology, the industry utilized deep ultraviolet (UV) light with a 193 nm wavelength to etch complex patterns onto wafers.

How is EUV light produced?

• The production of extreme ultraviolet (EUV) light, critical for manufacturing advanced semiconductor chips, involves a highly sophisticated process. To fabricate smaller and more powerful chips by cramming more transistors onto them, the semiconductor industry, including ASML, employs a method to generate 13.5-nm wavelength light.
• This method starts with propelling a 50-micrometer-wide droplet of liquid tin through the machine at a speed of nearly 300 km/hr.
• A laser then strikes the droplet, flattening it into a pancake shape. While still in motion, a second, more intense laser beam hits the tin, ionizing it into a high-temperature gas, 40 times hotter than the Sun’s surface, which emits the desired EUV light.
• This complex process, occurring 50,000 times per second, requires shooting 50,000 tin droplets and applying twice as many laser pulses to generate EUV light of adequate intensity for semiconductor lithography. Moreover, the entire operation is conducted in a vacuum to prevent absorption by air or any other substances, which could reduce the efficiency of EUV light production.

Precision and value of machine:

• The precision of the machine is extraordinarily high. The mirrors, produced by Zeiss, are the smoothest surfaces ever made, with imperfections so minor that, when scaled, the largest deviation would be just 1 mm high if the mirror’s surface were as large as Uttar Pradesh.
• To maintain this precision in directing light to the silicon wafer, the wafer stage floats on a magnetic field to eliminate friction and is adjusted with extreme accuracy—up to 50 picometers—20,000 times per second.
• This level of adjustment is critical for achieving the minuscule feature sizes required on modern chips, and the machine accomplishes this with an acceleration surpassing that of F1 cars or fighter jets.
• The “High NA EUV” machine represents a series of technological achievements that significantly advance the field of computing, playing a crucial role in the development of future technologies such as AI, robotics, intelligent vehicles, high-quality digital communication, and space exploration.
• Semiconductor chips, which these machines help create, are central to powering these innovations by performing the vast number of calculations they require.
• The continuous miniaturization and enhancement of these chips, in line with Moore’s law, have progressed from the first integrated circuit with just four transistors to modern chips with over 19 billion.
• Additionally, these lithography machines have strategic importance, exemplified by ASML’s restrictions on selling its advanced machines to certain countries, highlighting the geopolitical implications of semiconductor technology.
• These machines not only drive technological progress but also create high-skilled jobs and bolster national technological sovereignty.

Source: TH