Endpoint detectors are an important tool for achieving optimal process results.

Upgrade now and benefit from the following:

  • Enables etch depth monitoring and endpointing
  • Allows ‘etch-to-depth’ within a layer
  • Precise etch depth control within multi-layer structures
  • Allows endpointing on small samples or those that do not provide a strong OES endpoint

Laser Interferometry

  • A laser interferometer measures the change in reflectance of the wafer surface during etching (or deposition), by focussing a laser spot onto the wafer and measuring the intensity of the reflected laser light.
  • The laser interferometer camera provides the reflectance signal to the Oxford Instruments system PC along with an image of the wafer surface - to allow precise positioning of the laser spot onto the correct region.
  • The etch (or deposition) rate can be calculated by the monitoring the rate of arrival of the interference ripples of the reflected signal (since each interference cycle = λ/2n), allowing the etch to be stopped at a certain depth within the layer. Interfaces between layers can also be detected, as this typically results in an abrupt change in reflectance.
  • Laser interferometry typically requires user intervention to position the spot before each run (unless a specific region of the wafer is dedicated for laser endpointing), so is commonly used in a research environment.

Download the flyer

Laser Interferometry End Point Detector Flyer

Upgrade for etch tools using laser interferometry

PDF 1.72MB