Monolithic micro-grid-support technology

Ref-Nr: TDO0017

Monolythic thin film filter

Technology abstract

Micro-fabrication process engineered to manufacture metallic micro-grids. Such a supporting grid and accompanying metallic frame can be grown directly onto optical films or thin-film transmission filters dedicated to high energies and fluxes. The resulting monolithic component thus has no need for an adhesive to bind the film to its supporting elements. The grid bars can be as thin as tens of microns in width for a millimetre-size mesh.

Technology Description

A process involving different micro-fabrication steps has been engineered to manufacture grid-supported thin film optical transmission filters dedicated to high energies and fluxes. A supporting metallic micro-grid and accompanying frame can be grown directly onto an optical film as thin as 75 nm such as to obtain a monolithic component that eliminates the need for an adhesive to bind the film to its supporting elements. Both design and manufacturing of these grid-supported transmission filters for high energy electro-magnetic (Extreme Ultraviolet, X-rays) and particular radiations is done in-house.
Characteristics:

  • Metallic thin films (as thin as 75nm), metal-metal and metal-dielectric multilayers can be supported by a metallic grid of several microns in thickness (typically 50µm. Nickel is used as grid material. The overall component size is currently limited to 3x3 inches square but can be increased. The grid and frame pattern is freeform and directly grown onto the thin film.
  • Applications domains are high energy space astronomy, synchroton facilities, X-ray medical and analytical devices, fusion diagnostics, particle accelerators, proton therapy.

Innovations & Advantages

The main innovation in the presented manufacturing process is the direct growing of the metallic grid onto the optical thin film, and thus avoiding the need for adhesive connection of (grid) supports to the thin film. This monolithic architecture improves the thermal conductivity between the grid and the film to accommodate high fluxes. It also improves the mechanical robustness of the component.

Further Information

  • Min thin film thickness: 75nm (currently achieved)
  • Max grid thickness: 50µm
  • Max component size: 3x3 inches
  • Component frame and mesh patter: freeform
  • Thin film nature: all metallic thin film, several dielectric thin film
  • Metallic grid nature: Nickel (copper and gold can be envisaged)

Current and Potential Domains of Application

Current application:

  • High energy space astronomy (Optical filter in EUV imager)

Potential domains:

  • Filtering in other wavelength domains can be envisioned.
  • Synchrotron facilities
  •  X-ray medical and analytical devices
  • Fusion diagnostics
  • Particle accelerators
  • Proton therapy