[19a-436-1~8] 13.2 Exploratory Materials, Physical Properties, Devices

[19a-436-2] Synthesis of Mg₂Si thin film by thermal treatment under inert gas atmosphere and evaluation of film quality

〇Issei Horiba¹, Michinobu Fujiwara¹, Yosihiko Nakagawa¹, Kazuhiro Gotoh¹, Yasuyosi Kurokwa¹, Takashi Itoh¹, Noritaka Usami¹ (1.Nagoya Univ.)

Keywords:Magnesium silicide, Thermoelectric materials

Mg₂Si is promising as a n-type thermoelectric material. As a low cost method, we devised a method of heat treatment of Mg and Si substrates in an inert gas atmosphere to form Mg₂Si thin film. In this study, heat treatment was applied to samples on which Mg thin films were deposited on Si substrates and samples on which Mg ribbons were fixed on Si substrates, and the difference in film quality was investigated.In the first method, pure Mg particles were deposited on a Si substrate by evaporation. Thereafter, the sample was heat-treated. In the second method, Mg ribbon was placed on a Si substrate and heat treated under the same conditions. The film structure and film quality were investigated in XRD, SEM and EDX. Mg₂Si was formed on both sample and part of Mg₂Si was oriented in {100}. We confirmed that two layer structure consisting of an oxide film and Mg₂Si layer is formed in the sample prepared by the evaporation, on the other hand the uniform layer which is almost not oxided of Mg₂Si layer is formed in the sample used the Mg ribbon. Future tasks about method using evaporation and the method using ribbon are to prevent oxidation and to control film thickness,respectively.