声表面波压电薄膜异质金刚石结构的研究

Structure of piezoelectric thin film heterogeneous diamond with high frequency surface acoustic wave filter

采用电子回旋共振等离子体增强金属有机物化学气相沉积系统(ECR-PEMOCVD)在自持金刚石厚膜上沉积制备了氮化镓(GaN)薄膜材料。其中三甲基镓(TMGa)和氮气(N2)作为反应源,改变N2流量条件来实现高质量的GaN薄膜的沉积制备。实验结束之后,采用X射线衍射(XRD)、原子力显微镜(AFM)、电子探针(EPMA)和霍尔测量(HL)系统地研究了改变N2流量对GaN薄膜性能的影响。结果表明,在适当的N2流量条件下可以制备出具有优良结构和电学性能且具有优异表面形貌的GaN薄膜样品,而且镓和氮原子比对GaN薄膜的电学性能起着重要的作用。

GaN films were grown on free-standing thick diamond substrates by low temperature electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition(ECR-PEMOCVD).Instead of the conventional precursors(NH 3)for N source,the ECR plasma enhanced N 2 was applied as N source to achieve low temperature growth.The N 2 flux dependent structural and electrical properties of as-grown GaN films were systematically investigated,and the N 2 flux was optimized for achieving high quality GaN films.The results indicated that N 2 flux plays a critical role on the structural and electrical properties of GaN films through modulating the N/Ga atomic ratio,and high quality GaN films could be achieved by low temperature ECR-PEMOCVD under optimized N 2 flux.