Dual Beam Laser Interferometry

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This special "dual beam" or "twin spot" laser interferometer is recommended
for in situ rate/ depth measurements for processes using switching between
etch and deposition processes.
It measures the etch depth from the phase shift and polarisation difference
between the two laser beams without the getting synchronisation signals
from the etch tool and extrapolating the actual etch depth from the rate.


single beam laser interferometry

GaAs/ AlGaAs heterostructure VCSEL RIE

dual beam laser interferometry Laser Interferometry for Failure Analysis

AlGaN/ GaN ICP Etching

InP/ InGaAsP Laser Facet ICP Etching

SiGe RIE using a laser

Deep SiO2 Waveguide Etching by ICP

Polyimide Etching (RIE) for Failure Analysis

Laser CAIBE: InGaAs/ AlGaAs

GaAs/ AlGaAs DBR ICP Etching using Laser Interferometry

Plasmalab 80 Plus with laser mounted

optical emission

SiO2 via hole ething