NRL researchers have developed an extremely accurate technique to characterize the Young’s Modulus of thin film materials with nanometer thicknesses in a film-on-substrate situation. By utilizing this inventive technique, measurements of the Young’s Modulus are at least one order of magnitude better than measurements achievable with existing measurement techniques. When this technique is combined with the previous unpatented Shear Modulus measurement technique, a complete elastic characterization of isotropic thin films can be achieved.

While thin film materials have been used in applications ranging from computer chips, solar cells to wear-resistant coatings, it has been difficult to characterize the elastic properties of nanometer ranged thin films. Both existing static and dynamic methods measuring elastic moduli have deficiencies when involving thin films, the more effective dynamic method using mechanical resonators with a higher quality factor (Q). However, high Q resonators for thin films do not exceed a Q larger than 106. As a result, the elastic properties of thin film materials are either poorly characterized or not characterized at all.

The innovative NRL “Ultra High Q Silicon Cantilever Resonator” attains a high quality (Q) level for thin films due to two key reasons. First, the resonator is made from an intrinsically low loss material. A few examples of this material are high-quality, single-crystal lightly doped silicon or un-doped silicon. Second, excellent vibration isolation is established in the resonance mode to minimize external energy loss. As a result, an ultra high Q level of up to 5 x 107 has been attained for a thin film while still on a substrate.

Ultra High Q Silicon Resonator

Advantages

  • Previously unattained ultra high Q level two orders of magnitude higher resolution
  • Young’s Modulus of thin films achieved while thin film is still on substrate
  • Extremely sensitive to thin films as small as one monolayer

Applications

  • Thin Film Material Young’s Modulus testing equipment, and complete elastic characterization
  • Manufacturing, Packaging and Deploying Integrated Circuit (IC) Technology
  • Mechanical Resonance based Sensors such as Mass Sensors and Gas Sensors

Licensing and Collaborative Opportunities

  • US Patent No. US Patent 9,054,640 is available for license to companies with commercial interest
  • Potential for collaboration with NRL researchers

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