Researchers from TU Delft have built a lensless ‘EUV microscope’ to make images at the scale of 200 nanometers. With further refinement, they expect to able to image 5nm chip structures in the next two years. The technology may one day be used for in-line metrology purposes.
The imaging apparatus is a little bigger than a regular microscope: it’s a 5-meter large setup containing a powerful infrared laser, a giant box to generate EUV light and an imaging chamber. The infrared laser light is focused, then a noble gas is injected into the beam, which starts to emit much shorter wavelengths. Mirrors are used to shape the EUV beam and focus them on a sample which scatters the light: this scattering pattern is then captured by a camera in the imaging chamber. Specially-developed software translates the scattering patterns into an actual image.
The research project is part of the Linx consortium (Lensless Imaging of 3D Nanostructures with soft X-rays), a collaboration between five Dutch universities and a number of industrial partners that includes ASML.