AlN晶体在c轴方向具有很强的自发和压电极化效应,影响了其器件的性能。生长高质量的非极性面AlN晶体材料是解决该问题的有效途径。本研究结合AlN晶体沿c轴择优生长的特点,使用自行设计的双区电阻加热生长装置,升华制备出尺寸为厘米级m面非极性AlN单晶体,并利用X射线衍射和能谱对样品进行测试分析。实验结果表明AlN单晶体的方向为(100),铝和氮原子比例为50.3%和49.7%,接近理想比例1∶1。最后,对m面非极性AlN单晶体的形成机理进行探讨。
AlN materials and devices grown along the polar c-axis direction are affected by the strong spontaneous and piezoelectric polarization fields.To solve the question,it is necessary to grow nonpolar plane AlN crystals.The nonpolar m-plane AlN single crystals with the size about 1cm were grown by sublimation on a resistance heading furnace.The furnace designed by ourselves included two heaters,which heated on sublimation region and crystalline region,respectively.Then,AlN crystals were characterized by X-ray diffraction and energy dispersive spectrometer.The results show that the crystal is(100) oriented and consists of Al atoms(50.3at%) and N atoms(49.7at%).At last,the formation mechanism of m-plane AlN was discussed.