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采用扫描电子显微镜分别观察了用不同研磨机研磨、抛光及其经溴-乙醇腐蚀的HgCdTe体单晶片的表面二次电子衬度像。观察表明,研磨造成的晶片表面可见损伤,经机械和溴-乙醇化学抛光后将减少和去除。然而,化学抛光却造成个别表面凹陷和凸出,这些凹凸可能是溴-乙醇对表层夹杂物和基质的腐蚀速度不同所致。 相似文献
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With recently developed InN epitaxy via a controlling In bilayer, spectroscopic ellipsometry (SE) measurements had been carried out on the grown InN and the measured ellipsometric spectra were fitted with the Delta Psi2 software by using a suitable model and the dispersion rule. The thickness was measured by a scanning electron microscope (SEM). Insight into the film quality of InN and the lattice constant were gained by X-ray diffraction (XRD). By fitting the SE, the thickness of the InN film is consistent with that obtained by SEM cross-sectional thickness measurement. The optical bandgap of InN was put forward to be 1.05 eV, which conforms to the experimental results measured by the absorption spectrum and cathodoluminescence (CL). The refractive index and the extinction coefficient of interest were represented for InN, which is useful to design optoelectronic devices. 相似文献
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Ge组分对SiGe HBT直流特性的影响 总被引:1,自引:0,他引:1
制作了基区Ge组分分别为0.20和0.23的多发射极指数双台面结构SiGe异质结双极型晶体管(HBT)。实验结果表明,基区Ge组分的微小增加,引起了较大的基极复合电流,但减小了总的基极电流,提高了发射结的注入效率,电流增益成倍地提高。Ge组分从0.20增加到0.23,HBT的最大直流电流增益从60增加到158,提高了约2.6倍。 相似文献
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采用椭圆偏振光谱法,在1.50~6.50 eV光谱内,研究了在蓝宝石衬底(0001)面上使用金属有机化学气相沉积(MOCVD)的方法制备的非掺杂纤锌矿结构GaN薄膜的光学性质。建立GaN表面层/外延层/缓冲层/衬底四层物理结构模型。与Cauchy和Sellmeier色散公式比较后选择了Tanguy Extended色散公式来分析GaN薄膜的光学性质。椭圆偏振光谱拟合结果表明,Tanguy Extended色散公式能更准确、方便地描述GaN薄膜在全波段(特别是带隙及带隙之上波段)的色散关系。提供了GaN薄膜在1.50~6.50 eV光谱范围内的寻常光(o光)和非寻常光(e光)折射率和消光系数色散关系,为定量分析GaN薄膜带边附近各向异性的光学性质提供了依据。 相似文献
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采用掠入射X射线反射谱技术与原子力显微技术对属有机化合物化学气相淀积生长的AlxGa1-xN/GaN超晶格结构的表面和界面进行了精确表征。结合高分辨率X射线衍射谱与反射谱数据分析获得外延层各层厚度与AlGaN层的Al摩尔组分。掠入射x射线反射谱的显著强度振荡与原子力显微镜所观察到的台阶流动形貌表明了平整的界面和表面的存在。研究发现,低Al组分(x=0.25)且阱宽小的样品界面与表面粗糙度最小,通过原子力显微技术得到的表面粗糙度均方根偏差为0.45nm。 相似文献