Evaluation for GaN single crystals with high doping concentration by the terahertz ellipsometry

Gallium nitride (GaN) single crystals with high carrier concentration up to 10
²⁰
cm
^-3
order were evaluated by the terahertz time-domain spectroscopic ellipsometry. The electric properties such as carrier density are obtained by the fitting analysis based on Drude model. The terahertz ellipsometry is powerful non-contact and non-destructive evaluation method for semiconductors with high carrier concentration.