Study Of The Properties And The Quantum Structure Preparation Of Dilute Magnetic Germanium

Diluted magnetic semiconductor is a semiconductor material in which the nonmagnetic host ions are partially substituted by transition metals or rare earths ions with low doping concentration, and the charge and spin of electrons in conventional semiconductors will be exploited. The research on DMS has become one of the hot topics because of their potential application in spintronic devices, such as new generation of quantum computer, nonvolatile memory, pin—valve transistors, and so on. Therefore, DMS is focus of information science, semiconductor physics, chemistry materials and other disciplines. Ge-based DMS, due to its simple structure and is easy to achieve integration with conventional Si-based electronic devices. The Ge-based group IV doped transition metal Mn is the main contents of this paperPlasma-enhanced chemical vapor deposition (PECVD) and magnetron sputtering system were used to grow Ge diluted magnetic semiconductor thin films. We also use Mn/Ge co-sputtering method for preparation diluted magnetic Ge thin films in different concentration for comparison. Its morphology, structure, electricity and magnetism characteristics at different annealed temperatures were investigated. Scanning Electron Microscope(SEM),atomic force microscopy(AFM), X-ray diffraction(XRD), Raman spectrum and energy spectra were used to study the morphology and structures of dilute magnetic semiconductor thin films. Electrical characteristics was investigated by current-voltage (I-V) and capacitance-voltage(C-V) measurements; and magnetic property was used by vibrating sample magnetometer (VSM) measurement. All the samples were preparation on Si (p-100) substrate. After the vacuum annealing film becomes smooth and uniform particle size distribution. While the initial samples was unhomogenerously distributed on the substrate, and magnetic impurity cluster is not observed in samples. XRD measurements suggest that our samples show intrinsic Ge structure respectively, Mn ions has doped into the Ge lattice. XRD diffraction peak and Raman peak strongly enhances after annealing, which indicates the material crystallization enhanced. The samples show good the electrical characteristics investigated by I-V and C-V measurements, which indicates that doping does not change semiconductor electronic transport properties of Ge after annealing. Current and capacitance obviously increases under the same bias, and leakage flow decreases. At last, we found samples have ferromagnetic at room temperature.