Specific Process Knowledge/Characterization/III-V ECV-profiler

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III-V ECV-profiler

ECV profiler
ECV cell compartment
Doping profile example. Three n-doped layers and substrate separated by undoped layers

The ECV (Electrochemical Capacitance-Voltage) technique is used to measure carrier-density as a function of depth (doping-profile) on planar semiconductor structures - usually III-V compound semiconductors.

The ECV-profiler is maintained by DTU fotonik (not DTU Nanolab) and is therefor not in LabManager!

ECV is a destructive technique requiring a sample size of at least 5x5mm and good skills to obtain reproduceable and reliable results. The sample is placed in a electrochemical cell and electrical contacted to form a capacitor. This is done on one side through the electrolyte and on the other side via a ohmic contact on either the front- or the backside (preferred) of the wafer.

Note! We can only offer very limited help for this system. The ECV-profiler is not used very much and it is an old system. It has not been serviced for many years and it is very difficult (impossible) to get spare parts and technical support for it.

Equipment performance and process related parameters

Performance Excitation
  • halogen white light source for n-type measurements to generate holes for the etching process
Detection
  • between 10^13 to 10^20 carriers/cm^3
Sample size
  • from 5x5mm (10x10mm recommended) up to 2" approximately
Resolution
  • Minimum depth resolution ~1 nm
  • Measurement area:
    • small ring: Ø 1 mm
    • large ring: Ø 3 mm
Carrier density accuracy
  • very dependent on sample. Uncertainty can easily be +-50%.
Materials Allowed substrate materials
  • III-V
  • Silicon