Coherent Fourier scatterometry: a holistic tool for inspection of isolated particles or defects on gratings

Detecting defects on diffraction gratings is crucial for ensuring their performance and reliability. Practical detection of these defects poses challenges due to their subtle nature.We performnumerical investigations and demonstrate experimentally the capability of coherent Fourier scatterometry (CFS) to detect particles as small as 100 nm...

Coherent Fourier Scatterometry for Detection of Killer Defects on Silicon Carbide Samples

It has been a widely growing interest in using silicon carbide (SiC) in high-power electronic devices. Yet, SiC wafers may contain killer defects that could reduce fabrication yield and make the device fall into unexpected failures. To prevent these failures from happening, it is very important to develop inspection tools that can detect,...

Coating layer on samples with roughness: numerical study for coherent Fourier scatterometry

For the development of integrated circuits, the accompanying metrology inside the fabrication process is essential. Non-imaging metrology of nanostructure has to be quick and non-destructive. The multilayers are crucial components of today's microprocessor nanostructures and reflective coatings. Coherent Fourier scatterometry (CFS), which is...

Coherent Fourier Scatterometry for sensitive detection of subwavelength structures and particles

The phenomenon of scattering is ubiquitous. The human eye sees it as a ``blue" sky in a summer morning or a diffuse glow during the night, the color of a laser or fog in the air. Alternatively, scattering recorded with a state-of-the-art instrument manifests itself in collisions between atoms, electrons, and photons, such as processes in nuclear...

Coherent Fourier scatterometry nanoparticle detection enhanced by synthetic optical holography

We demonstrate that the sensitivity of nanoparticle detection on surfaces can be substantially improved by implementing synthetic optical holography (SOH) in coherent Fourier scatterometry (CFS), resulting in a phase-sensitive confocal differential detection technique that operates at very low power level (P=0.016 mW). The improvement in...

Direct detection of polystyrene equivalent nanoparticles with a diameter of 21 nm (∼λ/19) using coherent Fourier scatterometry

Coherent Fourier scatterometry (CFS) has been introduced to fulfil the need for noninvasive and sensitive inspection of subwavelength nanoparticles in the far field. The technique is based on detecting the scattering of coherent light when it is focused on isolated nanoparticles. In the present work, we describe the results of an experimental...

Effect of polarization in evanescent wave amplification for the enhancement of scattering of nanoparticles on surfaces

We demonstrate the far field detection of low-contrast nanoparticles on surfaces using a technique that is based on evanescent-wave amplification due to a thin dielectric layer that is deposited on the substrate. This research builds upon earlier results where scattering enhancement of 200 nm polystyrene (PSL) particles on top of a glass...

Machine learning techniques applied for the detection of nanoparticles on surfaces using coherent Fourier scatterometry

We present an efficient machine learning framework for detection and classification of nanoparticles on surfaces that are detected in the far-field with coherent Fourier scatterometry (CFS). We study silicon wafers contaminated with spherical polystyrene (PSL) nanoparticles (with diameters down to λ/8). Starting from the raw data, the proposed...

A highly sensitive laser focus positioning method with sub-micrometre accuracy using coherent Fourier scatterometry

We report a novel method of focus determination with high sensitivity and submicrometre accuracy. The technique relies on the asymmetry in the scattered far field from a nanosphere located at the surface of interest. The out-of-focus displacement of the probing beam manifests itself in imbalance of the signal of the differential detector...

Convolutional neural network applied for nanoparticle classification using coherent scatterometry data

The analysis of 2D scattering maps generated in scatterometry experiments for detection and classification of nanoparticles on surfaces is a cumbersome and slow process. Recently, deep learning techniques have been adopted to avoid manual feature extraction and classification in many research and application areas, including optics. In the...