Increasing Contrast with Quantum Photolithography
Have you ever wondered how the tens-of-nanometers wide transistors in our electronics are made? The answer is with an optical process called photolithography, and like other aspects of transistors, it is approaching a wall. Researchers in Russia however have developed a new photolithography protocol that could help it reach smaller scales, without sacrificing precision.
Photolithography works by shining a light pattern onto a chemical called a photoresist, which causes a reaction that etches into the substrate below the photoresist. Because of how light diffracts though, the edges of the pattern can have a lower contrast and that reduces the accuracy of the pattern. With quantum mechanics however, it is possible to etch higher resolution patterns, but previous quantum photolithography protocols have relied on multi-photon absorption and longer wavelengths of light. The new protocol uses single-photon absorption, which allows photons of much shorter wavelength to be used and higher resolution patterns to be resolved.
With improved edge-contrast and higher resolutions, perhaps we could see this protocol enable higher circuitry densities, by reducing the safe-distance between wires in computer chips.