Optoelectronic Properties Of Mg_xZn_1-xO Film Deposited By Radio Frequency Magnetron Co-Sputtering

MgxZn1-xO film is a new type of broadband gap semiconductor material. By varying the Mg composition, band gap can be tuned from 3.37 eV to 7.8 eV, so that MgxZn1-xO film has a widely applicable to the UV detectors and emitting fluorescence. In this paper, MgxZn1-xO films were prepared on sapphire, quartz and Si substrates by two-target radio frequency magnetron co-sputtering method.The properties of film were characterized with X-ray diffraction (XRD), scanning electron microscope (SEM) and UV-visible fluorescence spectrometer, etc. We studied that the effects of process parameters on the structure performance and optical properties of the film, such as sputtering power, sputtering temperature and annealing temperature and so on. A UV detector was prepared on quartz substrate to adopt wet chemical etching method. And the I-V properties of films were measured by hall test system. And the spectral responsivity of film was characterized with spectral response measurement system.The result indicates that the optimal sputtering powers of ZnO and MgO are 70 W and 120 W, respectively. And we could acquire the high quality film with sputtering time at 150 min and sputtering temperature at 220℃. The absorption edge of MgxZn1-xO film is located at 292nm. The emission peak of MgxZn1-xO film is located at 371nm, and its effective excitation wavelength is 330nm. The contact between Au and film is schottky contact. The response of UV detector is locates at 374nm and corresponding spectral responsivity is 0.0065A/W.