Identifying a Supernova is an event that astronomers usually celebrate with enthusiasm. And it is not for less if we take into account that they are one of the most violent events with which we can run into the cosmos. Knowing them better is very important because it can help us understand more precision How are the latest stages of the life of the mass stars, and also the mechanisms that explain how the material originated by the star synthesis can lead to new star systems.
The mathematical tools handled by astrophysics currently describe supernovae as the inevitable result of the depletion of nuclear fusion processes that take place in the core of mass stars. During the stage known as the main sequence, stars obtain their energy from the fusion of hydrogen nuclei. As this chemical element is consumed, the star begins to produce helium nuclei, and, of course, its composition begins to evolve.
During this process a huge amount of energy is released and the star is forced to continuously readjust to maintain hydrostatic balance, a phenomenon that is the result of the coexistence of two opposite forces capable of compensating. One of them is the gravitational contraction, which compresses the subject of the star, pressing it without rest. And the other is the radiation and gase pressure, which is the fruit of the ignition of the nuclear oven and tries to expand the star.
The small supernovae of the extreme ultraviolet lithography equipment
As we have anticipated from the holder, this article does not go only from Supernovas; It is also starred by the semiconductors. A priori we can intuit that these cosmic events and integrated circuits have nothing to do, but, curiously, they do have something in common. This is the reason why I found a good idea to start this text reviewing what a supernova is and why they occur. Otherwise we could not understand in all its extension the idea in which we are about to investigate.
The ultraviolet radiation generation process used by UVE lithography equipment is very similar to what happens during a Supernova
In the extreme ultraviolet lithography equipment (UVE) that manufactures the Dutch Company Asml, high power lasers instantly heat tens of thousands of tiny tin drops in a single second until they reach a temperature of half a million Celsius degrees. This interaction produces An extremely hot plasma that emits ultraviolet light with a wavelength of 13.5 nm. This light must later be transported to the wafer thanks to a very precise mirrors and lenses system with the purpose of capturing the patterns that define the integrated circuits on a layer of photorers.
Very broadly this is the strategy used by the most advanced semiconductor manufacturing machines that currently exist. And, as we have just seen, high -power lasers interpret an unquestionably protagonist role. As Jays Stewart, Chief of Research at ASML, explains in the very interesting article he has published in IEEE Spectrum, the ultraviolet radiation generation process used by UVE lithography equipment to produce avant -garde chips is very similar to what happens during a supernova.
When a massive star exhausts its fuel and stops nuclear fusion processes, radiation pressure and gases is no longer able to counteract gravitational contraction. This phenomenon causes the star iron core It suddenly contracts under the enormous pressure that all layers of material that it has above. The star has lost the hydrostatic balance. At this moment all this matter loses the support that the nucleus exercised, which is now much more compact, and falls on it with enormous speed.
When all that star material touches the surface of the nucleus there is a rebound effect that causes it to be fired with a huge energy towards the stellar medium, being disseminated. A supernova has just been produced. Some of them are so energetic that for a few seconds they emit more light than the entire galaxy that contains them. The tiny explosions that take place inside the UVE lithography equipment when a laser affects a tin drop produce a shock wave similar to that originating in the stellar medium, although much smaller scale.
Surprisingly the mathematical equations that describe the evolution of these two types of explosions are the same. ASML engineers use them to calculate very precisely how the evolution of the shock wave that triggers plasma balls within the UVE equipment will be. And astrophysicians use them to describe the remains of the supernovas and deduce the properties of the star explosion that originated them. A Supernova has 10⁴⁵ times more energy That an explosion of tin, but thanks to this parallel, ASML engineers have been able to solve the complex problem derived from tin residues inside their most advanced lithography equipment.
Image | ASML
More information | IEEE Spectrum
In WorldOfSoftware | ‘Focus: The Asml Way’: The book that reveals the secrets of the most powerful European company in the chips industry
