Full Surface Control for Nanoimprint Processes
Sub-micrometer structures more and more are used at biological, electrical, optical and photonic applications. And nanoimprint lithography is a simple and inexpensive pattern transfer technique to replicate them. For comprehensive process and quality control, dr.schwab offers multiple technologies and solutions. Working with visible light, dr. schwabs technologies offer quick full surface inspection and analysis in mass production. Beside the final product, also the template may be analyzed for irregularities and wear. In-line or off-line systems are available or tailored individually.
Analysis of Periodic Structures by Diffraction
Light diffraction is a very sensitive method to check size and shape of regularly arranged microstructures. Blue light allows to analyze structures with track pitch down to 300 nm. Using a line-scan camera even enables full surface pattern uniformity evaluation. This includes the detection of certain defect types such as
surface roughness, clouds or stripes, which are often quite extensive but are invisible to the usual camera inspection due to lack of contrast in zero order. Diffraction also is very effective to characterize stamper wear.
The first order diffraction camera picture at left clearly shows structure imperfections, which can not be recognized at all at the corresponding 0th order camera view at right.
Full Surface Structure Analysis by Spectrometer
Independent of structure size, the nanostructured layer may be analyzed by dr.schwabs spectrometer technlology: structure inhomogeneities are made visible, based on a calculation model applying a refraction index with gradient. dr.schwab systems are able to analyze this over the full surface within production cycle! This is realized by simultaneously measuring a big number of points using optical fibre multiplexing technology.