【摘要】 研究了用分子束外延设备在GaAs(001)衬底上异质外延生长ZnSeTe单晶薄膜材料的工艺技术。在VI族元素富集条件下,通过调节Se/Zn束流比,制备了全组分分布(x=0~1)的Zn SexTe1-x单晶薄膜样品。XRD分析结果显示外延生长的ZnSeTe薄膜样品呈现出单一的闪锌矿晶体结构。在450和550℃氮气氛保护下对Zn Se0.70Te0.30样品做了快速热退火处理,退火后发现其晶体质量和表面形貌都得到了明显改善:双晶X射线摇摆曲线(DCXRC)(004)衍射峰的半峰宽(FWHM)从0.707 7°降低至0.571 9°,表面均方根粗糙度从2.44 nm降低至1.34 nm。采用点In电极做室温Hall测试的结果显示,本征ZnSeTe薄膜表面In电极之间的电阻值很高,外延薄膜呈现载流子浓度很低的高阻状态。更多还原

【Abstract】 The technology of undoped ZnSeTe ternary monocrystalline films heteroepitaxial grown on GaAs( 001) substrates by molecular beam epitaxy( MBE) was studied. Under the VI-rich condition,the compositions x varying from 0 to 1 for Zn SexTe1- xepilayers were prepared by adjusting the Se / Zn beam equivalent pressure( BEP) ratios. XRD analysis results show that the ZnSeTe epilayers present a single zinc-blende crystalline structure. The crystalline quality and surface morphology of Zn Se0. 7Te0. 3samples were obviously improved after the process of rapid thermal annealing at 450 ℃ and 550 ℃ under the protection of nitrogen atmosphere. The full-width at half-maximum( FWHM) of the Zn Se0. 70Te0. 30( 004) diffraction peak decreases from 0. 707 7° to 0. 571 9°,and the root-mean-square( RMS) roughness diminishes from 2. 44 nm to 1. 34 nm. The Hall test was carried out using indium point electrodes at room temperature,the results show that the sheet resistance values of intrinsic ZnSeTe films are very high,and corresponding to the high impedance state of very low carrier concentration.更多还原