166 / 2019-03-23 15:17:01

Fabrication and optical properties of fluorescent SiC film on Si (100) substrate by Magnetron Sputtering

全体主题 > 功能薄膜（光、电、磁功能薄膜）

[Introduction] Silicon carbide (SiC) is a great semiconductor material with wide band gap[1]. It has advantages of low density, high hardness, high thermal conductivity, high electric field intensity, high carrier saturation drift velocity, high thermal shock resistance, excellent oxidation resistance and so on [1-3]. However, study of ultrathin nanoscale SiC nano-layer deposition on Si (100) single crystal substrate by Magnetron Sputtering at low deposition temperature was not reported. In this study, we prepared SiC nano-layer (below 10 nm) on Si (100) single crystal substrate by Magnetron Sputtering, and optical properties of SiC nano-layer were investigated.
[Experimental] Clean Si (100) single crystal substrate (10×10 mm) were put into Magnetron Sputtering (MSP300). The SiC magnetron sputtering source were α-SiC target (Φ 60 mm). The deposition temperature were from 298 K to 573 K. The deposition time was 12 mins. The power of RF Magnetron Sputtering was 140 W. The Ar gas flow was 40 sccm. The deposition pressure was 5 Pa, The Background vacuum was 4×10-4 Pa. The deposition processes were referred to references [4-5]. After Magnetron Sputtering deposition, the SiC nano-film were tested by X-ray Diffraction, Atomic Force Microscopy, Ultraviolet-Visible spectrum, Raman spectrum and Fluorescence spectrum.
[Results] Table I shows Effect of deposition temperature on colour of SiC nano-layer by Magnetron Sputtering. With increasing deposition temperature, the colour of SiC nano-layer was changed from dark purple to yellow. At deposition temperature of 473 K, with increasing deposition time from 12 mins to 16 mins, the colour of SiC nano-layer was changed from dark purple to deep blue. According to the results of XRD, the 4H-SiC nano-layer was maybe formed at deposition temperature of 473 K and deposition time of 16 mins. Fig. 1 shows 3-D Height morphology of SiC nano-layer at 573 K and 12 mins by Atomic Force Microscope. The thickness of SiC nano-layer island were ranged from 3 nm to 7 nm. The diameters of SiC nano-layer island were ranged from 30 nm to 60 nm. Fig. 2 shows fluorescence spectrum of SiC films. The fluorescence peaks were at 438 nm and 462 nm, the corresponding photon energy were 2.831 eV and 2.684 eV. The luminescence of indirect bandgap semiconductor SiC required phonon energy is 0.061 eV. The colour changing and band gap blue-shift of SiC nano-layer maybe be caused by the quantum size-limitation effects.