Spectroscopic Reflectometer

Near Normal Spectroscopic Reflectometer (Réflectomètre spectroscopique proche de la normale) is a fundamental instrument used for thin film thickness analysis for industry & research. Holmarc’s NNSR (Model No: HO-NNSR-02) is able to analyze thin film’s thickness, complex refractive index & surface roughness with high speed & repeatability. NNSR theory works with complex matrix form of Fresnel equations. Absolute reflectance spectroscopy is the principle behind Reflectometer; which is the ratio of the intensity of the reflected light beam (usually polychromatic) to the intensity of the incident beam. Light beam which normally incident on the sample surface in turn reflect from top & bottom of the thin film which get interfered & is directed through optical fiber (Bi-furicated fibre) to CCD attached spectrometer via computer. On the monitor we get spectrogram with interference oscillations directly proportional to thin film thickness. Holmarc’s Reflectometer can be used to analyze single, multi-layer, free standing & rough layer thickness of various stacks such as dielectric, crystalline, amorphous, metallic & absorbing samples. It also finds absolute transmittance & absorption directly for linear di-electric thin films. Roughness treatment is done with EMA modeling such as linear, Bruggemann & Maxwell garnet approximations. Manual scanning is provided for finding out roughness & uniformity of thin films. Without refractive index or any other optical properties, NNSR is able to find the thickness of thin / thick film & estimate its optical properties.