A Study on the Effect of 50 keV Nitrogen Ion Implantation in Mg2Si Thin Films

• Published in: SILICON 2023-10, Vol.15 (15), p.6521-6532
• Main Authors: Gupta, Suniksha, Howlader, Smita, Singh, Satyavir, Sharma, Atul, Asokan, K., Banerjee, M. K., Sachdev, K.
• Format: Article
• Language: English
• Subjects: Amorphization; Chemistry; Chemistry and Materials Science; Environmental Chemistry; Fluence; Inorganic Chemistry; Intermetallic compounds; Ion implantation; Ion irradiation; Lasers; Magnesium compounds; Materials Science; Metal silicides; Nitrogen ions; Optical Devices; Optics; Photoelectrons; Photonics; Polymer Sciences; Room temperature; Semiconductors; Silicides; Silicon substrates; Spectrum analysis; Stoichiometry; Structural analysis; Thermoelectric materials; Thickness; Thin films; X ray photoelectron spectroscopy
• ISSN: 1876-990X; 1876-9918
• DOI: 10.1007/s12633-023-02521-4

This paper reports the results of a study on the effect of N-ion implantation on structure and properties of Magnesium Silicide (Mg 2 Si) thin film that is known to be a potential thermoelectric (TE) material. Mg 2 Si thin films of thickness 300 nm have been deposited on the silicon (100) substrate at room temperature using the sputtering technique. The thin films have been subjected to 50 keV N-ion implantation under various fluence values ranging from 5 × 10 14 to 1 × 10 16 ions/cm 2 . Structural characterization by X-ray Diffraction (XRD) technique has verified that the pristine thin film is constituted by a crystalline single phase Mg 2 Si material; however, ion irradiation leads to partial amorphization of the Mg 2 Si thin film. Field–Emission Scanning Electron Microscopy (FE-SEM) with Energy Dispersive Spectroscopy (EDS) is employed to obtain microstructural and compositional information. While particle coarsening due to ion implantation is affirmed by FESEM observation, the EDS study cannot authenticate the exact stoichiometry of the film due to substrate effect. X-ray Photoelectron Spectroscopy (XPS) study was conducted to secure information about the chemical state of the elements at the film surface which confirms the presence of Mg 2 Si phase in the pristine film; and of both Mg 2 Si and nitrogen in the implanted thin films. The electrical transport behavior of Mg 2 Si thin films have been studied by way of I-V and Hall measurements; the conductivity values are found to increase from 6*10 2  S/m to 1.17*10 3  S/m as the fluence is raised from 5 × 10 14 to 1 × 10 16 ions/cm 2 at a temperature of 150 °C. The electrical conductivities of all the samples are seen to increase continuously with increasing temperature thereby, showing semiconducting behavior of the thin films. Graphical abstract