Thickness Measurement using Depth Interferometry

Logo Dip

The use of Differential Interferometry allows for continuous direct erosion rate and crater depth measurement along with the elemental depth profile analysis. This technique developed and patented by HORIBA Scientific is a major breakthrough for GD-OES as all the information, elemental composition and depth is now delivered in the same single experiment.


The erosion rates in GDOES are material dependent, and when multi-layers are measured, they change with depth. Previously, the estimation of these erosion rates was the result of calculations (based on recorded values for bulk materials and not well adapted to layers with varying densities) or external measurements potentially tedious.

DIP is crucially important when the investigated materials are non transparent as, in this case, Ellipsometry cannot be used.

  • Control of deposition processe
    DIP & GD provides precise layer thickness information for deposition experiments together with the follow up of the main constituent elements (composition, gradients) and the detection of contaminants.
  • DiP operation principle: Interferometric measurement
    DiP Operation Principle
    A laser source is separated into two beams: The reference one is directed on the intact surface of the sample, while the depth sensing one is directed on the middle of the GD measured area.
    The interference between the two reflected beams is measured as the sample is sputtered, giving a direct measurement of the crater depth.
  • Upgrade existing GD instruments
    DiP can be retrofitted on existing instruments as the design of the optical interface does not modify the light throughput towards the spectrometers.