2022 Volume 48 Issue 4 Article ID: 48-4-02
Group III-V nitride semiconductors were evaluated using photothermal deflection spectroscopy (PDS), which detects the heat generated by non-radiative recombination through the defect levels with high sensitivity. This method has the characteristic of being able to evaluate even electrically and optically inactive samples such as ultrathin films and ion-implanted samples. Since the PDS can evaluate the defect levels in the band gap with deeper range, it gives a new picture of the level in the band gap and valence band structure. Then, PDS method has been applied to the development of III-V nitride semiconductors as a relatively simple defect evaluation method. In this article, the improvement of the carrier transport of two-dimensional electron gas at the InGaN channel was demonstrated by detecting the alloy disorder with PDS method. Also, the behavior of Mg ion-implanted GaN caused by thermal annealing was discussed for the requirement to realize p-type conduction in term of the valence band structure and defects in the band gap evaluated by PDS.
