Growth and Characterization of Sb-Based Dilute Nitride Semiconductors by Sputtering

III-V-N alloys have a property called giant band gap bowing, in which the band gap decreases with increasing nitrogen composition in the low nitrogen composition region. This is due to the fact that the electronegativity of N atoms is significantly different from that of group III and group V atoms. InSb1-xNx alloys can obtain an even smaller band gap by band gap bowing because InSb is a narrow-gap semiconductor. Far-infrared optical devices with wavelengths of 8~14 μm, which is the window of the atmosphere, are expected to have various applications. There have been reports on the growth of InSbN&lt;span style="font-size:10.8333px"&gt; &lt;/span&gt;thin films by Molecular beam epitaxial (MBE) and metal-organic chemical vapor deposition (MOCVD) methods, but none by the sputtering method.<br/>In this study, InSb_1-xN_x was grown on GaAs (100) substrate by direct current (DC) magnetron sputtering method and characterized. InSb_1-xN_x thin film was grown on semi-insulating GaAs (100) substrate by DC magnetron sputtering method using the InSb (atomic ratio of 1:1) target. All samples were grown at a growth pressure of 5.0×10⁻¹ Pa, DC power of 0.10 kW, and growth time of 60 minutes. First, InSb thin films were grown by changing the growth temperatures to room temperature (RT), 150°C, and 300°C. As a result, we were confirmed that the peak intensities of (111), (220), and (311) planes increased as the growth temperature increased. Next, InSb_1-xN_x was fixed at 300°C and the flow rates of Ar [sccm]and N₂ [sccm] were varied 50:0 (a), 49:1 (b), 45:5 (c), and 40:10 (d), respectively. As a result, we were confirmed that the peak intensity of InSb_1-xN_x became weaker as the N2 flow rate increased. In sample (c), broad peaks were observed in the (111) and (220) planes of InSb, while no peaks were observed in sample (d). The N compositions of InSb_1-xN_x revealed by Secondary Ion Mass Spectrometry (SIMS) analysis were x = 0 for sample (a), x = 0.014 for sample (b), x = 0.07 for sample (c), and x = 0.11 for sample (d). We also confirmed that InSb_1-xN_x thin films with a maximum nitrogen composition of x = 0.20 can be grown by changing the flow rate ratio of Ar: N₂ to 0:10. From these results, we found that InSb_1-xN_x can be fabricated by sputtering by controlling Ar and N₂ gases.