Park Systems Accurion RSE Referenced Spectroscopic Ellipsometry device

Accurion RSE

Referenced Spectroscopic Ellipsometry Fast Inspection of Thin Films and Surfaces

The Referenced Spectroscopic Ellipsometer (RSE) is an ellipsometer-based reflectometer, designed for high-speed thickness mapping in, e.g., quality control. It allows to accurately measure of thicknesses ranging from 0.1 nm - 10 μm. With 200 complete spectra recorded per second, a 100 mm x 100 mm area can be investigated in only 12 minutes while acquiring 67,000 spectra.

Referenced Spectroscopic Ellipsometry in a Nutshell

Technology

What are the Benefits of Referenced Spectroscopic Ellipsometry Compared to Conventional Ellipsometry or Reflectometry?

The referenced spectroscopic ellipsometer combines the high sensitivity of an ellipsometer with the measurement speed of a reflectometer and even exceeds it. In comparison to a laser ellipsometer, it includes the spectroscopic information between 450 and 900 nm. This is important when more than one parameter of the processed layer is variable, such as thickness and optical density. Essentially, referenced methods are more sensitive than absolute methods. Therefore, the RSE method is superior to conventional ellipsometry when very thin layers are in focus. The advantage of increased sensitivity to thin films is even more evident when compared to reflectometry.

Technology

What is Ellipsometry?

Ellipsometry is a very sensitive optical method that has been used for about a hundred years to derive information about surfaces. It makes use of the fact that the polarization state of light may change when the light beam is reflected from a surface. If the surface is covered by a thin film (or a stack of films), the entire optical system of film and substrate influences the change in polarization. Therefore, it is possible to deduce information about the film properties, especially the film thickness.

Technology

How Does Referenced Spectroscopic Ellipsometry Work?

The RSE is a special type of ellipsometer, that compares the sample to a reference. In this way, the ellipsometric difference between sample and reference can be measured. Due to the orientation of the reference, none of the optical components need to be moved or modulated during measurement, and the full high-resolution spectrum can be obtained in a single-shot measurement. Thus, 200 spectra per second are acquired. The synchronized x-y stage enables acquisition of large-field film thickness maps within a few minutes. As the reference compensated system is an ellipsometer, the measured data needs to be fitted to an optical model to obtain optical parameters like the complex refractive index and/or the film-thickness. To deal with the high data rate, a look-up table fitting was implemented. Prior to the measurement, a look-up table is calculated. The measured data can then be fitted in real-time and in high resolution.

Key Features

  • "Single-shot“ referenced spectroscopic ellipsometric measurements
  • Data rate of 200 spectra per second
  • Live data processing for evaluation of film thickness
  • Spot size: 50 x 100 µm micro spot at AOI = 60°
  • Film thickness range: < 1nm – 10 µm
  • Spectral range: 450 – 900 nm
Park Systems Accurion RSE Referenced Spectroscopic Ellipsometry for fast thin film and surface inspection

Accurion RSE: Fast Wafer Inspection

Applications

Park Systems Accurion RSE Referenced Spectroscopic Ellipsometry Wafer Inspection

Wafer Inspection

Park Systems Accurion RSE Referenced Spectroscopic Ellipsometry Detection of Contaminants

Detection of Contaminants

Park Systems Accurion RSE Referenced Spectroscopic Ellipsometry thickness of ultrathin films

Thickness of Ultrathin Films

Park Systems Accurion RSE Referenced Spectroscopic Ellipsometry thickness of interlayer

Thickness of Interlayer