Accuracy and reproducibility of the electrochemical profiler

The electrochemical CV profiler (ECV) plays a key role in the characterisation of compound epitaxial structures. Epi suppliers and their customers need a procedure that ensures that the carrier concentration in any given layer lies within agreed limits. Carrier concentrations in optoelectronic device structures and HBTs are usually specified around ±20%, with tighter limits being applied to MESFET and HEMT structures. By understanding the factors that affect the accuracy and reproducibility of the ECV method, the standard deviation of the measurement, for uniformly doped epilayers, can be reduced to around 2%.