Precise process control of thin, transparent films is critical across a variety of markets and applications, including consumer electronics, semiconductors, and optics. Advanced Model Based Films Analysis (MBA) for the Nexview™ Optical Profiler is an application developed by ZYGO to enable quantitative 3D surface measurement and analysis of the structure and topography of thin optical films. MBA enables full-area topography and thickness characterization of transparent films as thin as 50 nm through the application of Coherence Scanning Interferometry (CSI) technology on the ZYGO Nexview™ optical profiler with Mx™ software.

To start measuring, users first need to simply define a nominal film stack. Materials for the film and the substrate are selected from a library of known materials, or by directly entering the indices of refraction and the thicknesses. The range of potential film thicknesses to search is also defined. Based on this input, the Mx™ software generates a library of possible signals and then compares these to measured signals within the full field of view. This produces a 3D map of thickness, along with surface maps for the top of the film and the substrate. Users are also able to define multiple regions with independent film stacks. This enables the software to accurately measure topography by compensating for the Phase Change on Reflection (PCOR) effect that arises from dissimilar materials.

Benefits of Films MBA include:

  • Full area metrology for films 50 nm or thicker
  • Simultaneous non-contact measurement of film topography, thickness, and substrate topography
  • Works across the entire range of objective and zoom magnifications – no limit to which objectives can be used
  • Requires only a simple optical flat for calibration
  • "Through the lens" operation with the profiler standard field of view, requiring no external or additional sensors
  • Enables accurate topography measurement between dissimilar opaque materials by compensating for Phase Change on Reflection (PCOR)
  • Robust measurement application requiring only nominal knowledge of the film

  • Applications for this innovation include a wide range of wafer-based semiconductor processes used in applications as diverse as MEMS devices, SoCs, LEDs, hard disk read/write head manufacturing, and films research and development at both the academic and institutional level.

    Competing tools will often require calibration using a witness sample of the part being measured or a range of film standards. But ZYGO's solution only requires calibration using a Silicon Carbide (SiC) optical flat, allowing thicknesses ranging from 50 nm to 2 µm with amazing results. Films MBA quickly and non-destructively provides simultaneous topography, thickness, and substrate mapping of a film structure, at any magnification, on a Nexview™ optical profiler.

    Zygo Corporation is a worldwide supplier of advanced optical metrology systems, high precision optical components, and complex electro-optical system design and manufacturing services. To learn more about the Films MBA application, visit our Thin Film Measurement web page.