基于电子回旋共振-等离子体增强金属有机物化学气相沉积技术生长GaMnN稀磁半导体的研究

Analysis of diluted magnetic semiconductor GaMnN grown by electron cyclotron resonance-plasma enhanced metal organic chemical vapor deposition

利用电子回旋共振-等离子体增强金属有机物化学气相沉积(ECR-PEMOCVD)方法,采用二茂锰(Cp2Mn)作为Mn源,高纯氮气作为氮源,三乙基镓(TEGa)作为Ga源,在蓝宝石(α-Al2O3)(0001)衬底上外延生长GaMnN稀磁半导体薄膜.反射高能电子衍射(RHEED)、X射线衍射(XRD)、原子力显微镜(AFM)表征了GaMnN薄膜的晶体结构和表面形貌.GaMnN薄膜均表现出良好的(0002)择优取向,表明制备的薄膜倾向于c轴方向生长,薄膜保持很好的纤锌矿结构.表面形貌是由许多亚微米量级的晶粒按一致的取向规则堆砌而成的.超导量子干涉仪(SQUID)用来表征薄膜的磁性.SQUID分析表明,薄膜呈铁磁性,铁磁性仅可能来源于三元相GaMnN,薄膜的居里温度高于350K.而且,高Mn的含量可以提高薄膜的居里温度.

Diluted magnetic semiconductor film GaMnN was grown on sapphire （α-A12O3）substrate using biscyclopentyldienyl manganese （Cp2 Mn）, N2 and TEGa by electron cyclotron resonance-plasma enhanced metal organic chemical vapor deposition （ECR-PEMOCVD） . The crystal structure and surface topography of the GaMnN films were characterized by RHEED, XRD and AFM. GaMnN films exhibit good （0002） preferred orientation, showing the films are inclined to c-axis growth and retain good wurtzite structure. The surface topography of GaMnN film is composed of many submicron grains piled in the consistent orientation. The magnetism of films is characterized by SQUID. SQUID shows that the film is ferromagnetic, which comes probably only from the ternary phase GaMnN and the Curie temperature of GaMnN film is higher than 350 K. Moreover, higher Mn concentration can enhance the Curie temperature of the film.