中文摘要：

采用脉冲激光沉积法在（0001）取向的GaN以及AlGaN／GaN调制掺杂结构上制备了（111）取向的BiFeO3（BFO）薄膜。首先在导电氧化物SrRuO3和TiO2缓冲层包覆的GaN上制备了BFO薄膜，分析了在CaN上生长的BFO薄膜的面外取向、外延关系、表面形貌以及电学性能等性质。然后，在AlGaN／GaN调制掺杂结构上采用TiO2缓冲层生长了BFO薄膜，并采用光刻工艺分别在ALGaN表面制备Ti／Al／Au欧姆电极和BFO表面制备Ni／Au肖特基电极以形成二极管结构。C-V测试表明，由于BFO铁电薄膜极化的作用，BFO／TiO2／AlGaN／GaN结构具有1V左右的逆时针窗口。

英文摘要：

The（111） oriented BiFeO3 （BFO） films were grown by pulsed laser deposition on substrates of （0001）- GaN and the modulation doped A1GaN/GaN. The microstructures and ferroelectric property of the BFO were characterized with X-ray diffraction,piezo-response force microscopy and conventional probes. The impact of the TiO2 buffer layer, deposited on the modulation-doped AIGaN/GaN substrate, on growth of the BFO films was studied. A Ti/Al/Ti/Au Ohmic contact was fabricated on AlGaN surface and a Ni/Au Schottky contact was made on BFO surface by e-beam lithography, respectively. The capacity-voltage characteristics measured at a frequency of 1 MHz show that an anti-clockwise C- V window with a width of 1.0 V exists possibly because of the polarization of the BFO films.