Tin Plasma Extreme Ultraviolet Radiation Makes 5nm Integrated Circuits Possible
Be it mobile end devices, autonomous driving, or Artificial Intelligence – miniaturization and automation in our digital world are placing ever-increasing demands on computer performance. The result: more and more transistors need to be placed on the semi-conductors inside chipsets. This is not a new phenomenon, as even one of the Intel founders knew that the number of transistors in an integrated circuit doubled around every 18 months. This has been dubbed “Moore’s Law” and still applies today; in fact it is how integration densities of up to 100 million transistors to one square millimeter have been reached. The size of semi-conductor structures is inching closer and closer to atomic dimensions. High-performance laser amplifiers by TRUMPF play a central role in the production of these chips. They help to create a luminous plasma which delivers extreme ultraviolet radiation (EUV) exposure to the substrate. In close cooperation with ASML, the world’s largest manufacturer of lithography systems, as well as Zeiss, the optical systems manufacturer, TRUMPF has developed a one-of-a-kind CO2 laser system which can process over 100 substrates an hour.
…is the wavelength of the extreme ultraviolet (EUV) light that is created, which facilitates the manufacture of structural sizes of less than 10 nanometers.
… are hit by the TRUMPF Laser Amplifier, to create EUV rays for substrate exposure.
transistors per square millimeter
… and more can be placed on a single microchip due to EUV lithography – which is almost inconceivable.
From tin droplets to substrate exposure: the EUV lithography process
Modern computer chips generally come in nanometer dimensions and can only be produced by complex exposure processes with the help of lasers. This is where the conventional approach with UV laser exposure by excimer lasers increasingly reaches its limit. Smaller structural sizes in ranges of less than ten nanometers can no longer be created with this existing method. These delicate structures require exposure to even shorter wavelengths – rays in the extreme ultraviolet (EUV) range.
The major challenge of EUV lithography is to generate radiation with the optimal wavelength of 13.5 nanometers. The solution: A luminous plasma generated by laser radiation that delivers this extremely short-wave radiation. But how is the plasma initially produced? A generator drops tin droplets into a vacuum chamber (3), then a pulsed high-power laser (1) by TRUMPF impacts the passing tin droplets (2) – 50,000 times per second. The tin atoms are ionized, and an intensive plasma is created. A collector mirror captures the EUV radiation emitted by the plasma in all directions, bundles it, and finally transfers it to the lithography system (4) for exposure of the wafer (5).