[22p-A301-1~15] 16.1 Fundamental properties, evaluation, process and devices in disordered materials

[22p-A301-7] Refractive index evaluation of Ge₂Sb₂Te₅ thin films
by transmission and reflection spectroscopy

〇Tamihiro Gotoh¹ (1.Gunma Univ.)

Keywords:phase change memory material, transmission and reflection spectroscopy, refractive index

Ge₂Sb₂Te₅ thin films are being applied as a phase change memory material. The transition from high resistance to low resistance is a high electric field phenomenon, and the level in the gap is considered to play an important role. The previously unknown level information in the gap of the Ge₂Sb₂Te₅ thin films is being clarified using photothermal deflection spectroscopy (PDS). On the other hand, the quantitative evaluation of the defect density by PDS requires an accurate refractive index of the sample. In this study, we investigated transmittance and reflectance in a wide wavelength range from visible light to infrared light, and estimated the refractive index of the Ge₂Sb₂Te₅ thin films.