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使用高真空电子束蒸发在p型Si(1 0 0 )衬底上制备了高kHfO2 薄膜 .俄歇电子能谱证实薄膜组分符合化学配比 ;x射线衍射测量表明刚沉积的薄膜是近非晶的 ,高温退火后发生部分晶化 ;原子力显微镜和扫描电子显微镜检测显示在高温退火前后薄膜均具有相当平整的表面 ,表明薄膜具有优良的热稳定性 ;椭偏测得在 6 0 0nm处薄膜折射率为 2 0 9;电容 电压测试得到的薄膜介电常数为 1 9.这些特性表明高真空电子束蒸发是一种很有希望的制备作为栅介质的HfO2 薄膜的方法 相似文献
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Transient Hole Trapping in Individual GeSi Quantum Dot Grown on Si(001) Studied by Conductive Atomic Force Microscopy 下载免费PDF全文
Electrical properties of individual self-assembled GeSi quantum dots grown on Si substrates are investigated by using conductive atomic force microscopy at room temperature. By controlling the bias voltage sweep in a certain fast sweep rate range, a novel current peak is observed in the current-voltage characteristics of the quantum dots. The current peaks are detectable only during the backward voltage sweep immediately after a forward sweep. The current peak position and intensity are found to depend strongly on the voltage sweep conditions. This kind of current-voltage characteristic under fast sweep is very different from the ordinary steady state current behaviour of quantum dots measured previously. trapping in the potential well formed bottom Si substrate. The origin of this phenomenon by the quantum dot sandwiched can be attributed to the transient hole between the native oxide layer and the 相似文献
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在材料科学中,样品的切割是一个重要的问题.目前常用的方法有电火花切割、超声切割、慢速锯切割等.这些方法普遍存在的一些问题是,切片较厚,精度难以控制,切口大,同时由于切割时的激烈振动产生形变和缺陷.这对于制备需要进行材料结构分析的样品来说是必须解决的难点.1987年10月在北京举办的第二届北京仪器分析测试国际会议和展览会上,波兰人民共和国科学院高压研究所推出的线锯引起国内科研机构的关注,但鉴于价格昂贵很难在国内推广使用.根据这一信息,在吸收消化进口仪器特点的基础上,中国科学技术大学与安徽省合肥市红旗木村厂协作,试制该… 相似文献
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Compositional and structural evolution of the titanium dioxide formation by thermal oxidation 下载免费PDF全文
Titanium oxide films were prepared by annealing DC magnetron sputtered titanium films in an oxygen ambient. X-ray diffraction (XRD), Auger electron spectroscopy (AES) sputter profiling, MCs^+-mode secondary ion mass spectrometry (MCs^+-SIMS) and atomic force microscopy (AFM) were employed, respectively, for the structural, com- positional and morphological characterization of the obtained films. For temperatures below 875 K, titanium films could not be fully oxidized within one hour. Above that temperature, the completely oxidized films were found to be rutile in structure. Detailed studies on the oxidation process at 925K were carried out for the understanding of the underlying mechanism of titanium dioxide (TiO2) formation by thermal oxidation. It was demonstrated that the formation of crystalline TiO2 could be divided into a short oxidation stage, followed by crystal forming stage. Relevance of this recognition was further discussed. 相似文献
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采用磁控共溅射技术制备了铒铥共掺杂氧化锌发光薄膜. 通过优化退火温度, 实现了薄膜的近红外 平坦宽带发射, 总带宽可达到~ 500 nm, 覆盖了光通信S+C+L+U 区波段. 此发射带由Er3+ 的1535 nm (4I13/2 → 4I15/2) 发射峰及Tm3+ 的1460 nm (3H4 → 3F4), 1640 nm (1G4 → 3F2), 1740 nm (3F4 → 3H6) 发射峰组成. 研究表明: 退火温度低于800 ℃ 时, 没有观察到薄膜样品明显的光致发光现象; 随着退火温度 从800 ℃ 升高到1000 ℃, I1640/I1535 发射峰强度比从0.2 升高到0.3, I1740/I1535 发射峰强度比从0.5 降低 到0.4, 发射峰强度比均基本保持稳定; 当退火温度高于1000 ℃ 时, I1640/I1535 发射峰强度比从0.3 升高到 0.6, I1740/I1535 发射峰强度比从0.4 升高到0.8, 发射峰强度比均急剧增加. 变温行为表明: 随着温度从10 K 逐渐升高到300 K, 谱线的总带宽基本不变, 在340—360 nm 之间; Tm3+ 在1640 和1740 nm 处的发射峰强度 分别降低了2/3 和1/2, Er3+ 在1535 nm 的发射峰强度增大了1.2 倍. 这是因为随着温度的升高, 声子数目增 多, Er3+ 与Tm3+ 离子之间发生能量传递的概率不断变大, 并且在Tm3+ 离子之间没有发生交叉弛豫现象. 相似文献