DuraSiN

Surface Roughness
Surface roughness AFM data for 100nm thick DuraSiNTM films is shown below. The data was acquired from a 5µm scan across the surface. The average surface roughness in the boxed area (ignoring the dust particle to the left) is 3.39 angstroms. Although some variation is expected from device to device, DuraSiNTM 100 and 200nm films typically have an average surface roughness in the 3.0-angstrom range.

DuraSiNTM products with 50nm films typically have a slightly larger average roughness than the 100nm and 200nm films. As determined by AFM, the 50nm DuraSiNTM films typically exhibit average surface roughness of about 1.2nm.

Surface Flatness
Flatness is a measure of how warped or bowed the surface is. As measured though a 20X DI microscope objective, the images do not demonstrate any measurable deformations. The regions around the 2- micron holes are completely flat, without any lip or curl around the edge of the hole allowing specimens to lay flat across the holes. The image of the film also does not show any deformations. As a reference, the pieces of dust viewable in the image stands out because of the difference in surface height with respect to the film.

Solvent and Acid Robustness
DuraSiNTM Films and Meshes are robust to most solvent and acid treatments, and can be cleaned with virtually any process required by your specimen preparation protocol. Solvents such as methanol, ethanol and acetone have no effect on the film. Acids, including sulfuric and nitric, also do not affect the film. Other common cleaning procedures such as the J.T. Baker solution and RCA cleaning are also acceptable.

Plasma and Glow Discharge Robustness
DuraSiNTM Film and Mesh products are made from silicon nitride and are extremely robust to glow discharge cleaning and high-energy oxygen plasma. This is particularly useful when there is a need to completely remove organic residues that could either affect the image quality or EDAX measurements. The products have been exposed to high-energy, 300W oxygen plasma systems typically used for removing up to microns of photoresist in the semiconductor industry, and no
etching was observed in spectroscopic thickness measurements. In addition, no degradation was observed when inspected through a high-power optical microscope.

Electron Transparency
Monte Carlo simulations on models of 100nm thick DuraSiNTM films, under the presence of a 120 and 200keV electron beam and probe size of 1 angstrom show almost zero electron scattering even after 10,000 trajectories are simulated. With standard available thicknesses from 50nm to 200nm and because of the amorphous structure of the film, atomic-scale resolution has been obtained with DuraSiNTM products, depending on the exact specimens under evaluation.

Chemical Robustness
The only acids which might adversely affect the films are 49% hydrofluoric acid when exposed for several minutes, or phosphoric acid when heated to temperatures greater than 150oC. The need for these chemicals at these conditions is generally quite rare.
Because the films are in the nanometer thickness range, it is also not recommended that the grids be exposed to an ultrasonic bath.
Cleaning for 30 minutes in concentrated sulfuric acid will generally remove organics and dust particles. Sometimes a final treatment in oxygen plasma or glow discharge is also applied.

Temperature Robustness
DuraSiNTM has been tested to temperatures near 500oC in ambient, and near 800oC in vacuum. No degradation, warping or bowing was observed using a 20X DI microscope objective. DuraSiNTM is expected to be stable at temperatures up to 1000oC, which make the grids well suited for high temperature deposition steps.