GaN材料作为第三代半导体材料, 具有宽禁带、 直接带隙、 耐腐蚀等优点, 是一种非常有前景的MOEMS材料。 由于GaN的刻蚀目前尚未成熟, 因此图形化外延生长法是一种较好的选择。 本文基于SOI（silicon-on-insulator）基片, 利用硅的微加工技术和图形化GaN分子束外延生长工艺, 设计并加工了工作在太赫兹波段的、 可以在二维方向上运动的SOI基GaN光栅。 光栅周期为16 μm, 光栅宽度为6 μm, 峰值位置为25901 μm。 通过仿真优化, 设计的微驱动器在水平电压220 V时, 水平方向上的位移为±726 μm; 垂直方向加200 V电压时, 垂直位移25 μm。 为了研究在图形化SOI衬底上外延生长的InGaN/GaN量子阱薄膜的光学性能, 用激光拉曼光谱仪对薄膜进行了光致发光光谱实验。 实验结果表明, InGaN/GaN量子阱薄膜具有良好的发光性能, 其发光范围为350~500 nm, 覆盖了紫外光到黄绿光。 由于局域态效应与禁带收缩的作用, 随着环境温度由10 K升高至室温, 薄膜的PL光谱的峰位呈现“S”形变化趋势。

As the third generation of semiconductor material, GaN has many advantages, such as wide bandgap, direct band gap, corrosion resistance and so on. Also, GaN is a very promising material for MOEMS. Because the etching of GaN material is not mature, epitaxial growth on patterned substrate is more helpful for GaN/SOI device. A movable GaN grating on patterned SOI substrate was designed and fabricated with Si micromaching and molecular beam epitaxy process of GaN. The grating actuated by a SOI electrostatic comb-drive micro-actuator could move in two dimensional directions and it could be used as filter in Terahertz wavelength. The period and width of the grating is 16 and 6 μm, respectively. The resonant wavelength is 25901 μm. An horizontal displacement of ±726 μm is obtained at 220 V of horizontal voltage with simulation. When the vertical voltage is 200 V, the displacement is 25 μm. The photoluminescence (PL) measurements of the deposited InGaN/GaN multiple quantum well on patterned SOI substrate are carried out with laser Raman spectrometer. The experimental results show that good optical property of the InGaN/GaN multiple quantum well. A wide emission wavelength from 350 to 500 nm is demonstrated. With the increase of temperature from 10 K to room temperature, the photoluminescence peak position appears a tendency of “S” shape because of the localized effect and band shrink in the InGaN/GaN quantum well.