The purpose of this article is to summarize the methods used to experimentally characterize a semiconductor material or device (PN junction, Schottky diode, etc.). Some examples of semiconductor quantities that could be characterized include depletion width, carrier concentration, optical generation and recombination rate, carrier lifetimes, defect concentration, trap states, etc.
Contents
- Electrical Characterization Techniques
- Optical Characterization
- PhysicalChemical Characterization
- Future Characterization Methods
- References
These quantities fall into three categories when it comes to characterization methods: 1) Electrical Characterization 2) Optical Characterization 3) Physical/Chemical Characterization
Electrical Characterization Techniques
Electrical Characterization can be used to determine resistivity, carrier concentration, mobility, contact resistance, barrier height, depletion width, oxide charge, interface states, carrier lifetimes, and deep level impurities.
Two-Point Probe, Four-Point Probe, Differential Hall Effect, Capacitance-Voltage Profiling, DLTS, Electron beam-induced current, and DLCP.
Optical Characterization
Optical Characterization may include microscopy, ellipsometry, photoluminescence, transmission spectroscopy, absorption spectroscopy, raman spectroscopy, reflectance modulation, cathodoluminescence, to name a few.
Physical/Chemical Characterization
Electron Beam Techniques - SEM, TEM, AES, EMP, EELS
Ion Beam Techniques - Sputtering, SIMS, RBS
X-Ray Techniques - XRF, XPS, XRD, X-ray topography Neutron Activation Analysis (NAA) Chemical Etching
Future Characterization Methods
Many of these techniques have been perfected for silicon making it the most studied semiconductor material. This is a result of silicon's affordability and prominent use in computing. As other fields such as power electronics, LED devices, photovoltaics, etc. begin to come of age, characterization of a variety of alternative materials will continue to increase (including organics). Many of the existing characterization methods will need to be adapted to accommodate the peculiarities of these new materials.