Study On Preparation And Magnetic Properties Of SiC Films

SiC is an important wide-gap semiconductor SiC-based DMS devices have been developed and gained considerable attention because of their excellent physical properties. Because of its wide band-gap, heat and other external influences do not readily disrupt the performance of SiC microelectronics. SiC devices can operate at higher temperatures and higher radiation levels. Recently, SiC has attracted much attention due to potential new device applications in spin-based information-processing technologies. Transition metals (TMs), such as Fe, Ni, Co and Mn, are common impurities in crystalline SiC grown by different technique and have been thoroughly studied by various experimental methods. However, TM-doped can introduce transition element clusters and destroy the excellent characteristics of SiC. First of all, this article describes the magnetic properties of the transition element doped SiC. The magnetic properties of non--magnetic element doped SiC thin films were reported in this work.Cu doped SiC films were prepared by magnetron sputtering technique, and their microstructures and magnetic properties were investigated. Some valuable results were obtained. It can be seen from the M-H curves that the as-deposited samples are diamagnetic. When the Ta reached 600℃, the Cu-SiC co-sputtered films occurred ferromagnetic transformation. With the Ta reached 800℃, the saturated magnetization no longer increased. The possible mechanism of ferromagnetic properties is carrier-induced ferromagnetism.The microstructures and magnetic properties of Al doped SiC films by radio frequency (RF) sputtering technique were reported. Al doped SiC film present FM behavior in their annealed states and the saturated magnetization of the film was about 2.1 emu/cm3. Al element can induce long-range magnetic order in the 3C-SiC, and Al doping with the calculated intergraded spin density 0.467μB.X-ray diffraction (XRD) analysis demonstrates that annealing can improve crystallization of the C-SiC co-sputtered films. Fourier transform infrared spectroscopy (FTIR) study shows that Si-C and Ai-C bonds exist in the C-SiC co-sputtered films.Room-temperature ferromagnetism was observed in the C-SiC co-sputtered films fabricated by RF sputtering. When annealing temperature (Ta) was increased from 800 to 1000℃, ferromagnetic ordering was present in the C-SiC co-sputtered films. The obvious magnetic domain structures were observed in the annealed film by magnetic force microscopy (MFM). Atomic force microscope (AFM) images show that carbon atoms uniformly distribute in SiC matrix.