Manufacturing Bits: July 3
Startup touts plasma fusion for EUV power source
Extreme ultraviolet (EUV) lithography has been delayed due in part to the lack of adequate power sources. But a spinoff from the University of Washington (UW) said it is developing a lower-cost version of a fusion reactor, which could one day become a viable power source to enable EUV.
The UW spinoff, Zplasma, is working on a plasma-based EUV source. The so-called ZaP project from the startup is a simple, linear source with no applied magnetic fields. It utilizes sheared axial flows to provide stability without affecting the properties of the Z-pinch.
In the system, four capacitors supply up to 10,000 volts of energy to separate the xenon electrons from their nuclei, creating an electrically charged plasma. It produces a Z-pinch plasma that is 100 cm long with a 1 cm radius. Zplasma’s light beam lasts 20 to 50 millionths of a second, about 1,000 times longer than typical EUV sources.
“That translates directly into more light output, more power depositing on the wafer, such that you can move it through in some reasonable amount of time,” said Uri Shumlak, a UW professor of aeronautics and astronautics.
“In order to get smaller feature sizes on silicon, the industry has to go to shorter wavelength light,” Shumlak said. “We’re able to produce that light with enough power that it can be used to manufacture microchips.”
A grant allowed the startup to verify that it could produce a 13.5nm wavelength of light. Another grant from the Washington Research Foundation helped it shrink the equipment from the size of a broomstick to a new version the size of a pin.
Heralded single photon sources could enable quantum memories
Quantum computing has generated a wave of interest. A quantum computer works by storing the 0s and 1s of information in quantum superposition states. They could one day solve problems that are impossible for even the fastest conventional supercomputers.
In a step towards the development of quantum computers, the National Institute of Standards and Technology (NIST), the University of California at San Diego, and the Politecnico di Milano in Italy have demonstrated the first heralded single-photon source made from silicon.
The 0.5mm x 0.05mm-sized heralded photon generator operates at room temperature and produces photons compatible with existing telecommunications systems at wavelengths of about 1550 nanometers.
A heralded photon is one of a pair whose existence is announced by the detection of its partner: the “herald” photon. To get heralded single photons, the group built upon a technique previously demonstrated in silicon called photon pair generation.
Illustration of the process of photon pair generation, in which input pump photons spontaneously generate special pairs of new photons that emerge at precisely the same time, with one at a slightly lower frequency and the other a slightly higher frequency, after which heralding occurs. Source: NIST
In the process, a laser pumps photons into a material whose properties cause two incoming pump photons to spontaneously generate a new pair of frequency-shifted photons. However, while these new photons emerge at precisely the same time, it is impossible to know when that will occur.
“Detecting one of these photons, therefore, lets us know to look for its partner,” said NIST scientist Kartik Srinivasan. “While there are a number of applications for photon pairs, heralded pairs will sometimes be needed, for example, to trigger the storage of information in future quantum-based computer memories.”
—Mark LaPedus
Tags: EUV, National Institute of Standards and Technology, NIST, Politecnico di Milano, quantum computing, UC San Diego, University of Washington, Zplasma