[16p-D505-1~9] 16.1 Fundamental properties, evaluation, process and devices in disordered materials

[16p-D505-6] In-gap level evaluation of Ge₂Sb₂Te₅ thin films
by infrared photothermal deflection spectroscopy

〇Tamihiro Gotoh¹ (1.Gunma Univ.)

Keywords:phase-change material, in-gap states, photothermal deflection spectroscopy

The Ge₂Sb₂Te₅ thin films can realize stable operation as a non-volatile electrical memory due to the reversible change in electrical resistivity. On the other hand, the transition from high resistance to low resistance is a high electric field phenomenon, and it is considered that the level in the gap plays an important role. In particular, the film quality of the amorphous phase is greatly affected by film forming conditions and thermal history. Therefore, photothermal deflection spectroscopy (PDS) extended to the infrared region was used to evaluate in-gap levels of samples under different sputtering conditions.