Name: comprehensive characterization of extended defects in semiconductor materials by a scanning electron microscope
Uploaded: 2016-05-28T14:00:00.000+00:00
Duration: 11 min 14 s
Description: Watch this Scientific Journal Video about Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope at JoVE.com

Support of this work by the German Research Foundation (DFG) within the framework of the Research Training Group 1621 is gratefully acknowledged by Paul Chekhonin. All authors are grateful to Dietmar Temmler (Fraunhofer FEP Dresden) for providing the electron beam processed Si samples showing liquid phase re-crystallisation. Special thanks go to Stefan Saager and Jakob Holfeld for the preparation of the figures for the SEM equipment and the EBSD set-up. We thank Michael Stavola for detailed discussions and help with this work.

1.样品制备冷冻-CL实验<ol><li>使用来自半导体材料的本体样品（这里:硅）具有平面表面，在0.2至0.5mm之间的范围内的5×5毫米，厚度的最大表面积。 </li><li>清洁样品和用有机溶剂如乙醇或丙酮的样品架。通过浸在氢氟酸（40％）和去离子水的在1:10的比例为1分钟的溶液除去样品上的氧化硅表面层。冲洗用去离子水样品。 </li><li>磨片的铟金属丝的机械，以形成具有对应于所述样品中，用厚度为约0.5mm的表面面积的铟箔。 </li><li>安装在一个金属套筒60°-pre-倾斜样本保持器，把铟箔上样品支架和顶部的样品。 </li><li>插座放置到加热板上。 </li><li>接通加热板，插座的控制温度与一体温计r和加热插座高达150℃，使得铟箔的熔化过程是迫在眉睫。 注意:这是没有必要的铟达到在157℃的熔点，但在箔应该韧性。 </li><li>按与1秒的牙签样品固定在铟箔样品。 </li><li>关闭加热板和冷却系统整体为约30分钟。 </li></ol> 2.样品制备超低温实验EBIC <ol><li>使用来自半导体材料的本体样品（这里:硅）具有平面表面，在0.2至0.5mm之间的范围内的5×5毫米，厚度的最大表面积。 </li><li>清洁样品和用有机溶剂如乙醇或丙酮的样品架。通过浸在氢氟酸（40％）和去离子水的在1:10的比例为1分钟的溶液除去样品上的氧化硅表面层。冲洗用去离子水样品。 </li><li>安装SAmple成金属化系统和蒸发金属（ 例如 ，铝在p型Si，Au载于n型Si）到样品的上表面上，以形成肖特基接触。 </li><li>沉积在硅样品的背面流体镓 - 铟的共晶的液滴，并涂抹过来以产生欧姆接触。 </li></ol> 3.样品制备ccEBSD实验<ol><li>通过施加研磨和抛光步骤以减小研磨和抛光剂的颗粒尺寸（序列上的一张纸上，然后钻石膏1微米，最后抛光制备的平坦样品表面例如 ，第一金刚石糊3微米上的振动抛光机与抛光悬浮液）。冲洗每个步骤之间的去离子水样品。 </li><li>通过清洗的乙醇样品在超声浴中3分钟完成表面处理。 </li><li>固定样品以由机械固定的金属样品架或通过粘接在双面粘接剂C阿尔邦标签。 </li></ol> 4.执行低温-CL实验<ol><li>确保冷冻剂如液氮（LN）和8小时的实验持续时间的液态氦（液氦）的可用性。 </li><li>使用低温阶段在SEM。 </li><li>插入从停车位置的聚光椭圆镜来测量位置成±SEM。 </li><li>挂载试验样品（这里:散装砷化镓样品）与舞台上的直接带隙的过渡。 </li><li>直到柱室阀门打开疏散SEM室。设置的SEM摄像参数加速度高压​​（HV）到20千伏，孔径大小为240微米，高电流模式ON时，电子束的扫描速度为1时，放大倍数为200和噪声降低到像素的平均值。 </li><li>使用埃弗哈特索恩利探测器用于二次电子成像。移动台朝向磁极片，直到电子束可在工作距离被聚焦为15mm的样品表面上（WD）。 </li><li>通过在电源切换为单色运行化学发光检测系统的启动程序，为光电倍增管的高电压电源（PMT），光电倍增管的冷却系统，并与CL的控制程序的笔记本电脑。启动CL控制程序，并选择PMT信号随时间变化的测量。 </li><li>为PMT的对比度（最大）和亮度（46％）设定适当的值。 </li><li>创建用于记录实验的日志文件。 </li><li>调整聚光镜由倾斜和旋转镜最大化测试样品的积分发光强度。记录使用CL控制程序CL测试光谱。 </li><li>宣泄室扫描电镜，取出试样，安装在铟箔实际样品的样品架并撤离SEM室。 </li><li>连结的出口用于与隔膜泵由柔性真空管入口S​​EM的低温气体。使用定心环具有O形环作为密封元件和固定它与夹紧环。通过在软管接头的衰减权重整合机械稳定系统。 </li><li>由柔性真空管连接膜片泵的出口到他再循环系统，如果它是可用的。使用定心环与O形圈作为密封元件，并与卡环固定。 </li><li>连接温度控制单元的温度传感器的扫描电镜阶段相应的插头连接器。打开温度控制部的电力供应。 </li><li>组装旁边的出口为SEM的低温气体柔性真空管加热胶带。 </li><li>戴防护眼镜和防护手套。插入用于将液体他入液氦杜瓦油管。在他传输管的出口连接以用于SEM的低温阶段的低温气体的入口。 </li><li>电子束参数HV至20千伏，孔径大小为240微米，高电流模式ON，则电子的扫描速度束为1时，放大倍数为200和噪声降低到像素的平均值。 </li><li>使用埃弗哈特索恩利探测器用于二次电子成像。移动台朝向极靴和所述电子束聚焦到由WD = 15毫米的CL实验样品表面。 </li><li>选择的样品表面上感兴趣区域和整个冷却下来的过程中对整个区域进行扫描。保证整个CL实验在感兴趣的区域中的样品的表面是由WD = 15毫米×阶段的适当的定位过程中。 </li><li>通过输入最低目标温度开始冷却下来的过程（ 例如 ，5 K）和适当的参数为根据本技术手册PID控制到温度控制器。打开液氦传输管的阀。 </li><li>监测样品温度，从隔膜泵的他的压力，并冷却下来的过程中从PMT输出的积分的CL信号。 - [R如果发光强度变得太高在低温下，以避免损坏PMT得出单色仪的狭缝宽度。 </li><li>增加液氦传输管的孔，如果必要，以达到目标温度。 </li><li>在达到目标温度后重新建立WD = 15毫米聚焦图像。整顿聚光镜上的实际样品最大积分发光强度的调整。 </li><li>对于光栅（300线每毫米，开拓在1000纳米）设定适当的值，光谱区域（1050〜1600纳米），步宽（5纳米），每个测量点（5秒）的时​​间和狭缝宽度（1毫米），用于在硅样品的光谱CL测量。使用CL控制程序，并将其保存到笔记本电脑的硬盘样品记录发光光谱。 </li><li>选择单色全色CL成像和大火，分别在光栅单色成像CL特定波长的平面镜。调整亮度和对比度在灰度值从PMT信号的依赖性的线性范围的CL图像的值。 </li><li>调整适当的图像分辨率（ 例如 ，1024×768像素），扫描速度和噪声降低方法的CL成像（ 例如 ，对于在200和1000之间的范围内的倍率与象素平均，或者更高的扫描合并的最低扫描速度14速8与平均线在20线）相结合。记录CL图像与SEM控制程序，并将其保存到计算机的硬盘上。 </li><li>输入姓名和每个光谱和图像整个测量会话到日志文件中测得的参数。 </li><li>关掉电子束的HV和通过输入较高的目标温度到温度控制器的温度依赖性的CL调查改变样品温度之前关闭SEM镜筒腔阀。 注意:这是为了避免电子枪的通过SEM室真空DUR的不稳定运转停止ING升温。 </li><li>打开SEM镜筒腔阀和当达到新的目标温度和在SEM室中的系统的真空稳定再次对高压切换。 </li><li>关掉HV的电子束，关闭SEM镜筒室阀，关闭该PMT中的快门，关闭PMT的电源和冷却器和在低温下完成计划的CL测量后运行的预热过程。 </li><li>除去已组装的低温CL实验无需打开SEM室中的附加设备和工具。 </li><li>离开SEM室封闭至少12小时。检查以确保样品保持器的温度为室温。否则，加热样品架，以RT打开SEM室之​​前。 注意:这是为了防止在SEM室中的水分。 </li><li>取下阶段样品并撤离SEM室。 </li></ol> 5.执行超低温实验EBIC <ol><li>恩确保液氦的8小时的实验持续的可用性。 </li><li>使用低温阶段在SEM。 </li><li>确保云母的板是可用的顶表面上蒸发的Au层。 </li><li>在样品保持器第一堆栈与Au层的片云母的向上，然后与肖特基接触向上云母的实际样本。把一个导电嘴的实际样品的肖特基接触和云母的蒸发Au层上的另一个。 </li><li>直到柱室阀门打开疏散SEM室。设置的SEM摄像参数HV，孔径大小，扫描速度，倍率和降噪的适当的值。 </li><li>打开样品电流放大器，选择测量范围，使得被显示在样品电流的三个小数位。 </li><li>创建用于记录实验的日志文件。 </li><li>从冷冻CL实验执行步骤4.12至4.16。 </li><li>设置S的适当值EM参数HV，孔径尺寸，放大率，扫描速度，和降低噪音的方法为EBIC成像（用于晶界的EBIC摄像参数推荐的范围是用于高压10至20千伏，20至60微米为孔径大小，30至1000对于放大，9至14为扫描速度和像素或帧平均）。 </li><li>使用EBIC成像样品电流检测器。移动台朝向极靴和聚焦电子束的WD在范围15至25毫米之间。 </li><li>选择的样品表面上感兴趣区域和整个冷却下来的过程中在所感兴趣的整个区域进行扫描。 </li><li>通过输入最低目标温度开始冷却下来的过程（ 例如 ，200 K）和适当的参数为PID控制成根据技术手册温度控制器。打开液氦传输管的阀。 </li><li>监控过程中冷却样品温度和压力，他从隔膜泵ING下来。 </li><li>拆分SEM屏幕并监测从并行Everart索恩利检测器以从样品电流检测器的EBIC信号的二​​次电子的信号，以观看与温度的图像的变化。 </li><li>重新调整SEM参数HV，光圈大小，放大倍率，扫描速度，并降低噪音以获得高对比度的图像EBIC。也重新调整试样电流放大器的测量范围，以避免在低温下显示溢出。 </li><li>在达到目标温度之后重新聚焦电子束。 </li><li>记录EBIC图像。输入名称和每个图像的参数到日志文件。 </li><li>关掉电子束的HV和通过输入目标温度的更高的值到温度控制器为温度依赖性EBIC调查改变样品温度之前关闭SEM镜筒腔阀。打开SEM柱室阀和高压开关时，新的目标TE当达到温度，系统真空再次稳定。 </li><li>关掉电子束的高压，关闭SEM镜筒室阀和在低温下完成计划EBIC测量后运行的预热过程。 </li><li>除去已组装的低温EBIC实验无需打开SEM室中的附加设备和工具。 </li><li>离开SEM室封闭至少12小时。检查，以确保样品保持器的温度为室温。否则，加热样品架，以RT打开SEM室之​​前。 </li><li>取下阶段样品并撤离SEM室。 </li></ol> 6.执行ccEBSD实验<ol><li>内的小的副或一个样品保持器是的销上安装样品预倾斜的范围内相对于电子束方向65°和70°之间。 <ol><li>可替代地，放置在6轴eucentric阶段样品中的SEM和倾斜整个舞台，使得样品表面法线和电子束的方向是在范围为65°和70°之间的角度。确保该阶段不会与检测器和室壁碰撞。 </li></ol></li><li>直到柱室阀门打开疏散SEM室。设置的SEM摄像参数HV（20千伏），光圈（120微米），高电流模式ON，扫描速度（ 例如 ，5），放大倍数（ 例如 ，3000）的适当值与噪声降低（象素平均值）。 </li><li>聚焦在样品表面上的电子束由WD在12和22毫米的范围内。 </li><li>关掉电子束加速电压和关闭柱腔阀。 </li><li>打开的EBSD检测器的电源。移动从停车位置的EBSD探测器测量在SEM室的位置。 </li><li>打开柱室阀门和开关上的电子束加速电压。重新聚焦电子束上的一个区域样品表面上的兴趣。 </li><li>打开EBSD控制软件和加载所选WD校准文件。 </li><li>根据操作手册中的EBSD控制软件设置测量。 </li><li>根据EBSD操作手册执行后台采集。 </li><li>读出的EBSD图案中心的位置，并从EBSD控制软件所选择的WD探测器距离。 </li><li>聚焦电子束在邻近的实际测量感兴趣的区域的样品的一个区域。离开光束扫描有约1小时的稳定。 </li><li>检查光束漂移的整个EBSD测定在此期间，必须不超过大于1μm的量。 </li><li>导航电子束的兴趣和重新聚焦的区域。 </li><li>计划行扫描平行于在感兴趣的区域中的倾斜轴。使用波束地图测绘（而不是舞台映射）设置。对于s的数量选择合适的值依照步骤（ 例如 ，100），步长大小（ 例如 ，50纳米），曝光时间（ 例如 ，43毫秒），帧平均（ 例如 ，10）和检测器的分级（ 例如 ，2×2）。 </li><li>一定要选择"保存所有图片"。禁用索引，以加快测量。 </li><li>直到最后扫描完成后运行线扫描。 </li><li>关掉电子束加速电压和关闭柱腔阀。 </li><li>从测量位置缩回EBSD检测器停放位置和关闭EBSD控制单元。 </li><li>发泄室，取出试样和撤离。 </li></ol> 7. CL-数据的分析: <ol><li>通过比较已知谱线的光谱位置检查光栅校准（ 例如 ，与在文献中的数据的体积和非应变的GaAs试样的发光行的峰），必要时修改波长校准。 </li><li>更正所记录的发光光谱（INT<html>密度对波长）相对于该光学系统的波长依赖性灵敏度其中通过在每个测量点除以测量的强度由相应灵敏度值由火灾光栅和PMT的。 </li><li>提取的CL图像的各像素的灰度值和平均灰度值对每个关心区域的图像中的，至少在与样品中的电子的相互作用体积的比例。 </li><li>从CL图像的平均灰度值的校正曲线确定用于感兴趣区域的发光强度，这取决于发光强度为PMT的给定的对比度和亮度的值。 </li><li>评价的平均发光强度我 CL整个CL图像和CL探测器的暗信号I 0。 </li><li>计算由以下等式的CL图像的对比度c CL亮和暗显示区域之间: D / 53872 / 53872eq1.jpg"/&gt; </li></ol> 8. EBIC数据分析: <ol><li>提取一个EBIC图像的每个像素的灰度值和平均灰度值对每个感兴趣区域，以量化的EBIC对比度方面的EBIC强度的空间变化。 </li><li>确定从由于C. Donolato和RO贝尔18的空间分辨的灰度值的EBIC对比度轮廓。 </li><li>计算出的EBIC对比曲线的面积和方差。 </li><li>根据由Donolato 14给出的规则确定的物理参数，如EBIC对比度轮廓的扩散长度，并从计算出的面 ​​积的少数载流子的表面复合速度和方差。 </li></ol> 9. ccEBSD试验分析<ol><li>使用内部编写的软件"ccEBSD"保罗Chekhonin的记录EBSD模式的评估程序。 </li><li>选择一个都是适宜ËEBSD图案将充当从应位于检体区域缺失的菌株的一个测量点的参考图案。 </li><li>应用上的图案的兴趣，至少15广泛分布的区域。 </li><li>使用的是由用于进一步评估EBSD控制软件确定的图案中心和检测器的距离的坐标。 </li><li>输入有关用于评价的参数，其余即 ，被分析的材料的弹性常数，在该行的步骤扫描和步长大小，检测器的尺寸和其在像素中，检测器的分辨率和试样倾斜角号码以及作为检测器分级。 </li><li> 2维傅里叶变换（的6像素内过滤和的40个像素外过滤）的计算过程中使用的带通滤波器。 </li><li>运行评估计划。 </li><li>宣读了评估文本文件的数值结果"protocol.txt"使用传统的电子表格程序W¯¯母鸡的计算完成。 </li></ol>

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The authors have nothing to disclose.

扫描电镜提供定位的扩展缺陷的半导体材料以及由ccEBSD，CL和EBIC调查的应用来表征它们的结构，光学和电学性质的可能性。在一般情况下，这是不可能在同一个样品同时执行所有三种方法。然而，通过不同的互补调查方法获得的结果的组合，在一个合理的顺序执行时，导致引起的扩展缺陷的影响的物理性质的更深入的了解。 为CL测量给出关于扩展缺陷的光学特性的信息，在协议中的一个关键步骤是将样品定位过程（步骤1.6），由于与样品中的缺陷不期望的退火的铟箔的加热期间（这确保了良好的样品的热和电接触与样本保持器）。提出的程序的替代是将样品安装到在RT由导电银膏中的样品架。然而，从经验它是公知的，在浆料中的有机溶剂可以在SEM的扫描过程中导致样品表面上的碳污染。污染恶化的CL图像的质量以及的EBSD衍射图案。此外，步骤4.21，需要特别注意，样品的冷却下来时可能发生的硅的发光强度的突然上升。这可能会损害光电倍增管的性能。相反，对于实际的样品意外低发光强度的情况下，应尽量提高聚光镜（协议号4.23）的调整，因为初步镜对准于测试样品在RT中进行稍有不同的波长范围。 关于该方法的仪器的局限性，人们必须考虑到，在非常低的TEMPERATURES与样品台上只有±5毫米的x方向和y方向这限制所调查的样品的区域移动。这种限制是由于他传输管的脆性断裂的危险。为在1.1和1.2给出低温实验样品的尺寸也由实验条件的限制。所以样品的表面积应调整到样品保持器的尺寸，以确保在散热片上的最佳热接触。硅样品的低推荐厚度限制了样品的低温实验中的温度梯度。为200μm的样品的厚度，用于在表面区域的主电子的相互作用体积的中心温度被发现相比于在样品保持器的表面测得的温度将增加小于5 K.。高扫描速度，只有在步骤4.5和4.17提出了降温过程中的低倍率，确保日感兴趣Ë区域保持清洁。这是因为通过其保持的温度始终略高于其充当在SEM室中冷凝阱残余气体样品区域的其余部分的温度的扫描电子束的热传递。通常，在步骤4.24对应于CL光谱中列出的所有参数都在体硅通过根据设备列表设置实验所谓D线发光的测量优化。的参数必须适应如果发光的调查是要在其它半导体材料进行。 独立观察发光的能量范围的，因为光从辐射复合过程来在整个重组体积被反射镜收集并因而从聚光镜CL测量结果的进一步局限性决定了对应的灰度值CL图像像素是分配编到样品表面上的电子束的位置。因为重组体积（这是相媲美的激发体积）的直径比，即使在低倍率的象素尺寸较大，这种效应导致的发光信号的空间的污点，并因此限制了空间分辨率。尽管如此，CL调查使单或全色发光的局部分布具有中等光谱分辨率的成像和可与光致发光的调查进行组合以得到更高的光谱分辨率。最近，作为一种替代的实验方法于CL测量，位错有关的光致发光的显微镜和光谱映射已提出的组田岛和同事26的。光致发光的映射的空间分辨率比CL图像清楚地低，但光致发光的调查还允许深能级发射带CORRE的偏振迟来位错在与扭曲和倾斜结构27,28 LAGBs确定。 在EBIC调查，其中给洞察扩展缺陷的电特性的情况下，存在用于在半导体材料的局部变化的电荷收集效率与同等的空间分辨率的成像没有替代方法。然而，同样对于EBIC测量，关键步骤包括在协议。所以，在步骤5.13，随着温度的降低该EBIC图像的变化，预计从扩展缺陷的温度依赖特性出现。然而，触头的质量可以在温度低于室温改变，从而影响了EBIC图像。温度影响，因为热膨胀从硅片分离的接触层中的不同系数的肖特基接触，与Al的适当层中的p型的情况下，并用Au在n型硅的情况下作出，N衬底。此外，通过镓 - 铟共晶制成的欧姆接触没有在温度低于160 K.通常稳定，接触质量的降低导致了大面积强烈降低EBIC信号。在这种情况下，触头必须被更新。在RT EBIC调查，还可以想到，对于EBSD测量中的接触可以通过将样品粘接到适当的载体板制成。 EBIC测量的另一工具限制是由接触尖端持有样品表面上方的突出造成的。为了防止接触尖端保持架和磁极片SEM的WD应至少为15毫米之间的碰撞。 在其可以被用来估计扩展缺陷的长程应变场ccEBSD调查的实验程序，以下的步骤是关键的。实验的最具挑战性的部分是样品制备，尤其是最后的抛光步骤（第rotocol号3.1），它具有必须仔细进行，以避免额外的表面缺陷的产生。如果不能得到菊池图案，样品表面的通常的质量是不够的。然而，从硅单结晶用的塑性变形后的表面上滑移线，一个良好的衍射图案可以得到这是非常适合的ccEBSD评价程序。这些样品的表面粗糙度用原子力显微镜产生为至多500纳米的范围内的高度变化进行分析。因此，非常高的内部应变或无定形表面层似乎是负责模糊衍射图案，而不是在样品表面的不完善平滑度。另一个问题可能是从相干散射电子的低信号相比于背景。然后在恒定加速电压和/或背景信号的更精确的测定（协议步骤号6.12）一个增加探针电流的再有帮助。到持久ccEBSD测量期间最小化样本移动时，建议以机械地固定样品（协议号3.2）。 如果相对于入射电子束在样品表面的倾斜是由该级的倾斜实现可能出现为ccEBSD调查工具的限制。有那么对于该样品的运动由于与极片和腔室壁碰撞风险强限制。此外，强烈建议只使用线扫描是平行于倾斜轴（因此SEM屏幕上水平出现），因为，首先，垂直扫描有内部株一大笔错误，由于样本的误差倾斜。第二，EBSD期间，横向分辨率越高沿不是垂直于它的倾斜轴线（约3为70°倾斜系数）。用于从ccEBSD调查对于硅算出的应变张量分量的值的下限为约2×10 -4这是随机错误。此外，必须强调的是，ccEBSD技术不能在大的晶格旋转（&gt; 4°）参照的基准点或非常接近晶界，其中来自不同的晶粒的EBSD图案重叠的存在下使用。关于应变测定的空间分辨率的ccEBSD调查的物理限制是由于其被认为是沿着样品倾斜轴线约为50nm的电子衍射的范围内。在用X射线衍射实验内部应变的测定相比较，这是因为，即使在X射线μ-衍射的情况下，X射线的显著较大相互作用空间的一个明显的优势。对于半导体材料，各向同性折射率扰动被polarscope调查也可以适用于内部应力的测定，但这种方法的空间分辨率低于几百纳米的29。在晶体的空间分辨三维应变状态的判定的另一种方法是基于高阶劳厄区域（HOLZ）行分割。该方法在使用电子干涉30的电子双棱镜的透射电子显微镜（TEM）来进行。然而，与此相反在SEM的ccEBSD调查，TEM研究需要箔从改变由于放松效果内部菌株样品的制备。 在今后的研究中，ccEBSD测量也将在较低的温度下进行。这将允许调查的结构，光学和电性能，不仅在相同的扩展缺陷，而且在相同的温度。

人们已经知道了几十年了扩展缺陷施加半导体材料1-3的电子结构的影响。上的电子设备和其他应用，例如传感器和太阳能电池材料的性能扩展缺陷的效果是根据广泛的实验和理论研究。然而，不存在对半导体的电子状态中的扩展缺陷的存在的计算一般接受的理论。这是由于电子结构计算的从理想晶格偏差的情况下，也向有关的种类和扩展缺陷的结构的大的多样性，以及它们之间，并与O形暗淡内在和可能的组合的复杂性外在缺陷。 主要类型的扩展缺陷是位错（1维缺陷）和晶界（2维缺陷）。在下面，我们共同在可在扫描电子显微镜（SEM）进行的实​​验中的术语ncentrate上这两种类型的扩展缺陷的。这里介绍的实验方法得到约扩展缺陷的结构，光学和电特性，因此，在含有扩展缺陷的半导体材料的电子态的间接知识信息。缺陷相关的电子态的控制是用于半导体的应用和半导体器件的操作的核心问题。 为扩展缺陷的结构的调查，电子背散射衍射（EBSD）技术都可以应用。通常，一个EBSD测定通过点映射与在每个点处的固定的电子束进行。 EBSD然后产生关于在与多晶材料的晶粒的单晶材料的情况下的样品的晶格的结晶取向的信息。佛R，它将目的由菊池线形成的实验确定的衍射图案必须通过与来自结晶空间群的材料的确定模拟图案比较来进行分析。如果为定向数据的评估的软件能够计算相邻的映射点的晶体学坐标系之间的取向差角，在它们之间的晶界的类型可被确定。如果取向差角小于15°，以低角度晶界（LAGB）的存在;否则它是一个大角度晶界（逐渐增强）。类型逐渐增强的特点是它的Σ值其中Σ-1晶格点躺在巧合晶格的部分。因此，Σ= 3代表的高度对称孪晶界4。如果在样品表面的两个平面的EBSD映射可以与映射的位置的精确知识，晶界平面w的类型来测量第i米勒指数的hkl也可以通过由兰德尔5提出了一种方法进行评价。 最近，对于电子衍射图案的评价的新程序由威尔金森等人的。6，它允许完全局部应变张量的所有分量，计算即 ，三个正应变的绝对值三个剪切应变组件。这种计算对每个测量点相对于具有相同的晶体取向上的无应变晶体区所取的参考图案进行在映射从相应衍射图案。该评估程序是基于使用的互相关技术，它给人的名字ccEBSD的电子背散射衍射图案特征的小变化的决心。相对于一个选定的参考点时，应变分量和晶格旋转可以为10 -4和0.006＆＃精度来测量176 ;,分别为7。管线施加ccEBSD测量跨晶粒边界扫描，或沿位错的安排，可以在本地确定的数量以及这些扩展缺陷的应变场的范围内。 位错和晶界的光学性质可通过光谱和成像阴极（CL）的技术来研究。发光信号由在半导体材料由SEM的一次电子束产生电子 - 空穴对的辐射复合引起的。的发光强度正比于辐射复合效率即总少数载流子寿命的放射性复合的时间的比率。当此比率由缺陷局部的影响，在发光分布的对比度可在CL图像观察到。正常情况下，延长缺陷作为非辐射复合中心，因此，第l从带波段重组uminescence在扩展缺陷的附近相比于不受干扰半导体降低。然而，在硅，锗和一些化合物半导体材料，在位错以及晶界上的情况下，特性发光频带观察表示光子能量比（直接或非直接）带 - 能带重组下在散装材料8-10。作为一个例子，键合的硅晶片，并通过关口和同事11-13多结晶硅的广泛的CL调查显示，位错和LAGBs负责在带隙浅和深能级的发生。相应的辐射跃迁被表示为在CL光谱D谱线。然而，伴随着和由氧沉淀和过渡金属杂质位错的安排错位污染的应变场的作用仍有争议的interpretatD线发光的离子。但是，如果发光线到一个不同的扩展缺陷的能量位置的分配可以成功地制成，然后在发光光谱此特定线的发生可以作为这一缺陷的存在的信号。以增加的发光强度， 即 ，相对于非辐射一项所述的辐射复合，CL调查具有在低温（冷冻CL）与间接带结构的半导体材料来进行。 这里考虑的扩展缺陷的电特性被成像在SEM的电子束感生电流（EBIC），其特征。当由一次电子束产生电子 - 空穴对被内置的电场分离，可以观察到这个电流。可以通过扩展缺陷本身的电势或通过样品表面上的肖特基接触生成该字段。该EBIC图像对比从电荷收集效率的局部变化的结果是由于在电活性缺陷的变化的重组行为。的扩展缺陷通常显示出增加的载流子复合，以使其显示在比无缺陷区域的EBIC图像变暗。在缺陷14基于物理模型的框架内，在空间的EBIC信号，这是所谓的对比度信息，的相关性的定量评价使少数载流子扩散长度和寿命的测定，以及在表面复合速度。因为这些参数是依赖于温度，EBIC调查应也可在低温（冷冻EBIC）进行，以获得增强的信噪比。备选地，依赖于温度的EBIC测量根据其提出Kittler和同事15,16模型启用的深能级杂质浓度的测定在位错。 17不能用扫描电子显微镜来解决显著影响。然而，该实验方法，ccEBSD，CL和EBIC相结合，提供了可视化的扩展缺陷和在SEM量化其基本特性的机会。对于未来的应用中，不仅故障分析，而且缺陷控制和缺陷工程的目的，这个强大的工具将在半导体器件性能的提高具有重要作用。

<table><tbody><tr><td>Cryogenic liquids:&amp;nbsp;&amp;nbsp;&amp;nbsp;</td><td>Linde http://www.linde-gas.de, Air Liquide http://www.airliquide.de/</td><td></td><td></td></tr><tr><td>Liquid helium ( LHe )</td><td></td><td></td><td>for cooling of the cryostat</td></tr><tr><td>Liquid nitrogen ( LN2 )</td><td></td><td></td><td>for cooling of the PMT R5509-73</td></tr><tr><td>Indium wire</td><td>chemPUR http://chempur.de/&amp;nbsp;</td><td>900898</td><td>CL sample preparation: for good electrical and thermal coupling between cryostat and sample</td></tr><tr><td>Mica</td><td>plano GmbH http://www.plano-em.de/&amp;nbsp;</td><td>V3</td><td>isolation of EBIC sample holder and good thermal coupling to the cryostat</td></tr><tr><td>Aluminium wire, gold wire</td><td>chemPUR http://chempur.de/&amp;nbsp;</td><td>009013, 900891</td><td>purity 99.99%, material for formation of Schottky contact for EBIC measurements</td></tr><tr><td>Indium-Gallium eutectic solution</td><td>Alfa Aesar&amp;nbsp;</td><td>12478</td><td>to form ohmic contact on the backside of the sample for EBIC measurements</td></tr><tr><td>Liquid chemicalsVLSI Selectipur&lt;br/&gt; &amp;nbsp;(de-ionized water, acetone, ethanol)</td><td>VWR</td><td>52182674,&lt;br/&gt; 51152090</td><td>for sample preparation: cleaning and surface treatment</td></tr><tr><td>Hydrofluoric acid</td><td>VWR</td><td>1,003,382,500</td><td>necessary to remove surface oxide layer on Silicon samples immediately before investigation; follow safety precautions!&amp;nbsp;</td></tr><tr><td>MicroCloth</td><td>Buehler http://www.buehler.com/&amp;nbsp;</td><td>40-7222</td><td>polishing cloth</td></tr><tr><td>MasterMet 1 (0.02 &amp;micro;m)</td><td>Buehler http://www.buehler.com/&amp;nbsp;</td><td>40-6380-006</td><td>SiO&lt;sub&gt;2&lt;/sub&gt; polishing suspension</td></tr><tr><td>Scanning electron microscope (SEM)</td><td>Carl Zeiss AG http://www.zeiss.de/microscopy/&amp;nbsp;</td><td>Ultra 55</td><td>field emission gun</td></tr><tr><td>SEM-CL system</td><td>EMSystems</td><td></td><td>customized, following equipment belongs to CL system:</td></tr><tr><td>&amp;nbsp;SEM stage for cryostat</td><td>Kammrath &amp;amp; Weiss http://www.kammrath-weiss.com&amp;nbsp;</td><td></td><td></td></tr><tr><td>KONTI cryostat</td><td>Cryovac http://www.cryovac.de/</td><td>3-06-4609C-7674</td><td>cooling of sample</td></tr><tr><td>Liquid He transfer line for KONTI cryostat</td><td>Cryovac http://www.cryovac.de/</td><td>3-01-3506C-SO</td><td></td></tr><tr><td>Cryogenic Temperature Controller</td><td>Cryovac http://www.cryovac.de/</td><td>TIC-304 MA</td><td>controlling the flow rate of cryogenic</td></tr><tr><td>Photomultiplier Tube (PMT)&amp;nbsp;</td><td>Hamamatsu http://www.hamamatsu.com</td><td>R5509-73</td><td>for NIR spectral range&amp;nbsp;</td></tr><tr><td>PMT housing and cooler</td><td>Hamamatsu http://www.hamamatsu.com</td><td>C9940-2</td><td></td></tr><tr><td>HV power supply&amp;nbsp;</td><td>Heinzinger electronic GmbH http://www.heinzinger.de/</td><td>LNC 3000-10 neg</td><td>for operating of the PMT</td></tr><tr><td>Monochromator&amp;nbsp;</td><td>Sol Instruments Ltd. http://www.solinstruments.com</td><td>MS2004i</td><td></td></tr><tr><td>PMT&amp;nbsp;</td><td>Hamamatsu http://www.hamamatsu.com</td><td>R3896</td><td>for visible spectral range</td></tr><tr><td>CCD digital camera&amp;nbsp;</td><td>Proscan GmbH, Proscan Special Instruments Ltd. http://www.proscan.de</td><td>HS 101 H</td><td>for visible spectral range</td></tr><tr><td>Control program</td><td>Proscan GmbH, Proscan Special Instruments Ltd. http://www.proscan.de</td><td>PSI line</td><td>for controlling spectral CL measurements with CCD or PMT detectors</td></tr><tr><td>Laptop</td><td>Dell</td><td>Latitude 110L</td><td>hardware for running the control program</td></tr><tr><td>&amp;nbsp;LHe dewar</td><td>cryotherm http://www.cryotherm.de/</td><td>Stratos 100 SL</td><td>container for cryogenic</td></tr><tr><td>LN2 dewar</td><td></td><td></td><td>container for cryogenic</td></tr><tr><td>Protective glasses</td><td>pulsafe</td><td></td><td>protective equipment</td></tr><tr><td>Protective gloves</td><td>tempex</td><td>Protect line&amp;nbsp; Mod. 4081052</td><td>protective equipment</td></tr><tr><td>Heating tape</td><td>Thermocax Isopad GmbH http://www.isopad-solutions.com</td><td>IT-TeMS 6</td><td>to prevent or reduce icing of the flexible hoses during cooling</td></tr><tr><td>Diaphragm pump&amp;nbsp;</td><td>Vacuubrand GmbH &amp;amp; Co KG http://www.vacuubrand.com</td><td>ME4</td><td>to provide the flow rate of the cryogenic</td></tr><tr><td>Vacuum accessoires: flexible hoses, seals, locking rings</td><td></td><td></td><td>connectors for cryogenic CL or EBIC set-up</td></tr><tr><td>Specimen current EBIC amplifier</td><td>KE developments / Deben http://deben.co.uk/</td><td>Type 31</td><td>Measuring the EBIC current</td></tr><tr><td>High vacuum chamber with metal evaporation</td><td>customized</td><td></td><td>formation of Schottky contact for EBIC measurements</td></tr><tr><td>Heating plate</td><td>Retsch GmbH http://www.retsch.de</td><td>SG1</td><td>CL sample preparation</td></tr><tr><td>EBSD detector Nordlys</td><td>HKL</td><td></td><td>no more available; can be replaced by the Oxford EBSD detectors NordlysMax3 or NordlysNano</td></tr><tr><td>EBSD acquisition and evaluation software Channel 5</td><td>HKL</td><td></td><td>no more available; can be replaced by the Oxford EBSD Software AZtecHKL</td></tr><tr><td>ccEBSD program ccEBSD_v1.07.exe</td><td>in house written program</td><td></td><td>for use please contact authors</td></tr><tr><td>EBSD interface with remote control system</td><td>Carl Zeiss AG http://www.zeiss.de/microscopy/&amp;nbsp;</td><td></td><td>necessary for the electron beam control and parameter transfer between EBSD system and SEM&amp;nbsp;&amp;nbsp;</td></tr><tr><td>Vibromet2</td><td>Buehler, http://www.buehler.com/&amp;nbsp;</td><td>671635160</td><td>vibratory polisher</td></tr></tbody></table>

comprehensive characterization of extended defects in semiconductor materials by a scanning electron microscope

Extended defects such as dislocations and grain boundaries have a strong influence on the performance of microelectronic devices and on other applications of semiconductor materials. However, it is still under debate how the defect structure determines the band structure, and therefore, the recombination behavior of electron-hole pairs responsible for the optical and electrical properties of the extended defects. The present paper is a survey of procedures for the spatially resolved investigation of structural and of physical properties of extended defects in semiconductor materials with a scanning electron microscope (SEM). Representative examples are given for crystalline silicon. The luminescence behavior of extended defects can be investigated by cathodoluminescence (CL) measurements. They are particularly valuable because spectrally and spatially resolved information can be obtained simultaneously. For silicon, with an indirect electronic band structure, CL measurements should be carried out at low temperatures down to 5 K due to the low fraction of radiative recombination processes in comparison to non-radiative transitions at room temperature. For the study of the electrical properties of extended defects, the electron beam induced current (EBIC) technique can be applied. The EBIC image reflects the local distribution of defects due to the increased charge-carrier recombination in their vicinity. The procedure for EBIC investigations is described for measurements at room temperature and at low temperatures. Internal strain fields arising from extended defects can be determined quantitatively by cross-correlation electron backscatter diffraction (ccEBSD). This method is challenging because of the necessary preparation of the sample surface and because of the quality of the diffraction patterns which are recorded during the mapping of the sample. The spatial resolution of the three experimental techniques is compared.

在半导体材料中的扩展缺陷的结构，电学和光学特性通过在扫描电子显微镜不同的实验方法研究。一般地，它是能够调查在同一样品这些性能，并与有关的样品制备，即使是在像晶界或位错的局部结构的明确的单一缺陷一些努力。然而，应该指出的是，由于与用于物理缺陷性能的检查的半导体材料的一次电子束的特定相互作用产物，其可以通过CL，EBIC或ccEBSD调查可实现的空间分辨率彼此不同。在图1中 ，示意性附图给出了SEM的适合于在低温下的CL测量（ 图1A），用于EBIC调查的组件的相应的设定（ 图1B </强&gt;），以及必要的（cc）的EBSD测试（ 图1C）的主要硬件元件的布局。 所有这里给出的代表性结果列于硅得到作为与间接电子能带结构的半导体材料的展示。这种带结构阻碍所有发光测量由于辐射跃迁的比较与直接带隙半导体结构的概率很低。为了实现足够的发光强度为保证统计结果是具有挑战性的。在下面，实验程序用于通过塑性变形以及由在硅单晶的液相重结晶诱导位错的调查说明。此外，在硅的双晶与双晶界及低角度晶界调查呈现。 图2A示出的铟箔的试样的适当定位的一个例子，以保证良好的热接触，以在该温度由热电偶测得的冷冻样品架。通过实验证明，对于硅，在原始状态，测定为Si单晶约200至500微米的样品厚度很适合于在温度下降到在图2B中给出5 K的化学发光光谱低温CL调查之后，塑性变形和另外的退火后。在SEM的电子束，在20千伏的电子束加速电压和大约45 nA的在散焦扫描模式的探针电流，这是由于电子 - 空穴对的产生导致高发光强度在大体积（运行大约（450×250×3）微米3）中度激发密度。在这种扫描模式中，样品表面实际上是对WD = 15毫米，但电子一个WD = 0被调整。对于C大号成像，当然，该电子束被聚焦其产生几纳米的样品表面上，但与一些微米的一次电子的相同穿透深度作为散焦扫描模式中的电子束的光点直径。每幅图像采集的时间与商店分辨率1,024×768像素是像素模式下平均约10分钟，在电子束的扫描速度14。有人计算和实验证实了散焦扫描模式样品区的所研究的温度上升不超过某些0.1ķ通过热能传递更多由于电子束。在聚焦模式下，本地样品加热强烈依赖于热导率而这又取决于样品掺杂和本身的温度20。用于生长Si样品，浮子区p掺杂以10 15 cm -3的浓度的硼，在聚焦扫描模式中，局部温度升高ΔT约2千发生在5 K的低温恒温器的温度，以及ΔT的≈0.3ķ在25 K. 研究位错的光学性质，体Si样品在800℃后，在295兆帕的第二变形步骤在420℃下16兆帕的压力进行塑性变形。滑移线，变形的样品的一部分的表面上， 如图2C所示，由位错滑移过程在两个不同的111面向滑动面而引起的。滑线可以通过背散射电子（BSE）可视化。滑移线表示在其上的大部分位错排列的晶格面的痕迹。单色CL（单CL）图像（ 图2D和2E）均在D4和D3发光带的充满活力的岗位收购并没有从所造成的防滑纹路的表面形貌轮廓显著受到影响。这是由CL调查验证的压脚提升仔细表面抛光其显示相同的几乎不变的发光条纹图案作为最初波状样品表面，其中所述发光强度条纹图案是平行于滑动面的痕迹上。如果计划从图像定量分析的CL发光强度的局部分布，则CL图像具有要被记录在CL信号和灰度值之间的关系的线性范围。这种关系可以通过实验，通过测量图像的灰度值和在用于检测器给出对比度和亮度值的光电倍增器的绝对信号之间的相关性来确定。相反，如果打算以可视化的样品表面上化学发光强度的小的变化，那么为获得最佳效果，非线性信号对灰度值的关系应已经期间在SEM成像过程施加。上在低温下的堆积硅样品的CL图像的空间分辨率由相互作用的大小决定样品中的初始电子的量，因为这种相互作用体积的大小仅比容积为电子-空穴对21的辐射复合稍微小。对于聚焦和固定梁的相互作用体积的直径是在给定的实验条件22下约3微米。 周围由ccEBSD扩展缺陷应变场的估计需要的具有足够质量，甚至在高应变样品区域菊池图案记录。一个例子在图3A中给出。为了获得这些模式中，样品表面应无不需要的表面层（氧化物，碳污染等 ）。良好的结果可以用下面的实验参数来实现:在20千电子伏和12 nA的，样品表面60°和70°，以在WD = 15毫米入射光束，2×2的EBSD DETE之间的正常的倾斜电子束男星像素合并而产生的672×512像素的分辨率，在EBSD探测器上每帧20和43毫秒之间设置为高，曝光时间信号的放大增益，平均超过每个测量点和菊池的存储九时五十五帧模式为无索引每个测量点的图像。一个菊池图案的总采集时间可以从曝光时间乘以帧加上10几毫秒的数量由于所必需的电子束偏移的时间被估计，读出和存储。 50 nm的数值竟然实验是EBSD映射内的两个样本位置之间一个很好的最小步长。这与关于为电子衍射对比度达到的分辨率近理论考虑23一致。避免了EBSD映射期间光束漂移，建议运行映射前等待至少15分钟，在感兴趣的区域的近邻的光束扫描。结果发现，只EBSD线扫描平行于样品倾斜轴提供逼真的应变数据与在同一行上的参考图案。否则，实际样品倾斜角的非常小心判定是需要的，或者可选的线的长度垂直扫描到倾斜轴必须被限制到几个微米。 的菊池图案存储为8位的JPEG通过傅立叶变换（FT）和互相关与节目"ccEBSD"由作者（PC）的一个写评价。该方案是基于由威尔金森开发等人6的算法，将详细参考说明。 19.在菊池图案，几个（15 - 19）的子模式（128×128像素）具有与特征如亮带交叉（参见图3A和3B）被定义。所有子图案必须通过FT进行分析。的带通滤波器已被应用到所有的FT图像（内半径6圆周对于低频，外半径为40个像素为较高频率）xels设置为零的所有值在傅立叶空间（带通滤波器参见图3C）的外部。然后将交叉相关（cc）的函数（ 图3D）必须从基准菊池图案中的每个子图案与子图案的各自的FT（ 图3E和3F）的FT之间计算。从CC-功能（ 图3D）的峰的位置，所述子模式的相对位移可被确定。使用这些位移，可以计算出在正常和剪切应变分量。如果材料相关的弹性常数是已知的，也应力分量可被确定。在由福格特的符号，这些常数C 11 = 165.7 GPA，C 12 = 63.9 GPA和C 44 = 79.9 GPA对硅具有立方晶格24。结果从一个菊池巴的所有子模式的组合ttern提高应变评价的准确性。从在硅单晶上的无缺陷区域的ccEBSD线扫描确定的统计误差被发现是2×10 -4的所有应变张量分量。然而，为了获得用于扩展缺陷的情况下定量结果，一个菊池图案作为基准图案的选择是重要的。如果，例如，样品是完全由位错， 如图2所覆盖，由Jiang等 25提出复杂的程序可以应用于以找出适当的参考图案。 对于使用ccEBSD的情况是由一个高能量的电子束处理以诱导液相再结晶的Si晶片（[001] -表面取向）容易（ 见图4）。围绕重结晶的轨道，滑移线是BSE图像指示DISL可见平行于图像（ 图4A）的边缘上滑动面ocation异动痕迹。的CL调查，在相同的实验条件作为塑性变形样品下进行。单-CL图像，记录在带-能带跃迁（ 图4B，4C和4D分别）和D4和D2错位发光频带的能量，显示所造成的重的扩展缺陷的空间分布结晶成过程。带 - 能带跃迁和D线发光带之间的本地反相关可以从单CL图像来推断。这是由分别在电子束的光点模式样本位置1，2和3（参见图4A）测得的发光光谱（ 图4E）的支持。从作为重结晶轨道（ 图4A中的白线）的前一个行扫描进行ccEBSD调查，局部应变张量的直流电阻沿行扫描TS可确定（ 图4F和4G）。据验证，该统计误差范围内，该值不依赖于其中使用特定菊池图案作为基准图案，如果这图案位于在带 - 能带跃迁是主导的区域。当正常菌株TR（ε）的总和超过5×10 -4的值的位错有关的电子跃迁出现。因为TR（ε）不等于零为在大约150微米的长度接近重结晶轨道的一个区域中的扫描，有在接近样品表面的体积平均晶格膨胀。根据弹性的线性理论，如在评估程序"ccEBSD"预先假定的正常应力σ33是等于零。如果有在EBSD行扫描的裂纹，那么ccEBSD评估不能在整个扫描与一个参考图形由于菊池图案CAU的急剧变化进行由裂缝的几何效应的sed。 在原理上可以由用于在硅晶界的结构，光学和电特性的调查所述的实验方法来实现什么示于图5为p型掺杂的具有10 17厘米的硼浓度的Si双晶-3。常规的EBSD地图产生在其中由获取软件的图案采集后立即进行仅菊池图案的索引的地图的每个点上的结晶方位的全部信息。此外，还晶界的类型可以通过常规的EBSD数据管理程序（ 图5A）显示。用于检测LAGB的，临界角，必须在两个相邻测量点的晶格的取向差限定。的1°的最小值被证明是合适的。为了LAGB在EBSD图所示，取向差角为4.5°。相同的采样区域（ 图5B）的EBIC图像在室温测定。非相干Σ3晶界与LAGB在这里显示为暗线。这种效果是由局部增加载流子复合导致的。从EBIC信号跨越LAGB（参见， 图5H），（60±12）微米的扩散长度和（4.1±0.4）一个复合速度的对比度轮廓×104 厘米秒-1测定的少数载流子在该模型由Donolato 14的框架。所述EBIC图像中的单个暗点，分布在整个样品表面并浓缩尤其在LAGB附近，表示穿透位错的位置。在在4K的CL成像调查，LAGB在带-能带跃迁能量（ 图5C），如预期的，但surprisi出现单CL图像中暗ngly也在D4的频带（ 图4D），它通常被分配给位错的能量的单CL像。然而，LAGB看起来亮的单CL图像在对应于D1 / D2发光频带（ 图5E）1530纳米的波长。该发光行为被认为是由点缺陷在构成LAGB位错的附近感应。此外，作为线横跨LAGB扫描以确定其本地应变场进行的ccEBSD过程。在电子束加速电压降低到10千伏，以增加在增加的总采集时间为每个菊池图案为代价的应变测定的空间分辨率。正常和剪切应变分量，在图5F和5G所示，分别不能用于LAGB的中心区域计算（超过约50nm），因为双模式似乎防止菊池图案进行分析。更多以上，对LAGB两侧的EBSD图案具有与两个不同的参考图案相关联，因为只能适用于衍射图案的小变化的互相关方法。这样，两个参考图案，收集在左手侧和LAGB的右手侧，由于两个子颗粒之间的大取向差角。尽管如此，这是令人激动的应变分量表现对称地对LAGB的两侧。为应变分量的位置依存性的图表表明LAGB的应变场的范围延伸至大约350纳米到两个子颗粒。与此相反，带-能带跃迁单CL图像中的局部改变对比度的图，和的EBIC图像（ 图5H）中的EBIC信号对比度，表明LAGB对发光信号的影响并在EBIC信号范围可达±10μm且从中心±1.5微米<html>在LAGB的分别。这验证从对扩展缺陷的不同属性的调查当地的分辨率很大程度上取决于所采用的实验方法和参数开始发言。 <img alt="图1" src="/files/ftp_upload/53872/53872fig1.jpg" /> 图1.设置为CL，EBIC和ccEBSD测量。（A）的扫描电镜与场发射枪，不同孔径成像和分析，对低温样品架中，CL聚光镜的样品，单色仪和红外光电倍增管为红外光;（B）所述样品EBIC调查和（C）设置为可数值进行分析，以获得对晶体取向的信息的菊池图案的形成和存储的肖特基接触以及由ccEBSD晶格扭曲。D / 53872 / 53872fig1large.jpg"目标="_空白"&gt;点击此处查看该图的放大版本。 <img alt="图2" src="/files/ftp_upload/53872/53872fig2.jpg" /> 图2. CL光谱及成像调查在塑性变形硅单晶。（A）上放置在低温样品架铟箔硅样品。 （B）为高纯度的Si单晶（原生）测得的发光光谱，用于塑性变形样品，并经过附加的退火。在光谱的特性的转换标记为通常与BB为一个带 - 能带跃迁和D1至D4对于位错引起的发光频带。变形Si晶体的表面（C）上滑行通过背散射电子（BSE）成像（由图2A红色箭头标记）。这些结果表明，对于不同的滑移SYSTE塑性变形女士。在图2D和2E，对于D4线和D3线单-CL图像显示，分别有各自的BSE图像（ 图2C）所示低于同一样品区域进行测量。 <a href="https://www.jove.com/files/ftp_upload/53872/53872fig2large.jpg" target="_blank">请点击这里查看更大的版本这个数字。</a> <img alt="图3" src="/files/ftp_upload/53872/53872fig3.jpg" /> 图3.图像中可视化分析ccEBSD的课程步骤:（A）从子模式实际样品位置全部菊池花样。 （B）的其中一个子模式的和（C）其过滤傅立叶变换。 （E）从在样品和（F）的过滤傅立叶变换的基准位置对应的子图案。 （D）的交叉相关函数（CCF），从副图案的傅里叶变换计算的。在CCF的亮度提高了20％，以可视化的详细信息。 <a href="https://www.jove.com/files/ftp_upload/53872/53872fig3large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图4" src="/files/ftp_upload/53872/53872fig4.jpg" /> 图4. CL和ccEBSD调查对于硅晶片重新结晶后。（A）中从一个Si晶片的表面上具有由高能电子束处理后的轨道再结晶材料的BSE图像。点1，2和3 CL光谱调查位置标记，以及在其中执行ccEBSD扫描与方向箭头线。在（A）所示的样本区域的（BD）单CL图像，在带-能带跃迁（B）的有活力的位置采取D4（C）和D 2（D）的发光带。 （E）发光光谱在沿线扫描（A），从ccEBSD调查计算出的1点，2和3的正常（F）和剪切应变分量（G）进行测量。 <a href="https://www.jove.com/files/ftp_upload/53872/53872fig4large.jpg" target="_blank">请点击此处查看大图这一数字。</a> <img alt="图5" src="/files/ftp_upload/53872/53872fig5.jpg" /> 图5. EBSD，在一个硅碧晶体上的Si的双晶，在黄色和黑色的一个LAGB孪晶晶界HAGBs和LAGB。（A）中的EBSD取向图EBIC，CL和ccEBSD调查 。正常晶粒表面的取向表示。 （B）在样品区的RT（A），其中相干（黄色箭头）和incohere EBIC图像NT（蓝色箭头）双晶界表示。 （CE）在BB（C）的能量的单CL照片，D4（D）和D1 / D2（E）的属于其由EBIC图像（B）在一个红色矩形标记LAGB区域。正常（F）和来自整个LAGB ccEBSD调查计算出的剪切应变分量（G）。在4K和在横跨LAGB RT中EBIC图像将BB单CL图像中找到的相反的（H）的比较。在应变分量图和在CL-和EBIC对比图请注意，在不同的缩放X坐标。 <a href="https://www.jove.com/files/ftp_upload/53872/53872fig5large.jpg" target="_blank">请点击此处查看该图的放大版本。</a>

Watch this Scientific Journal Video about Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope at JoVE.com

Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope

The optical, electrical, and structural properties of dislocations and of grain boundaries in semiconductor materials can be determined by experiments performed in a scanning electron microscope. Electron microscopy has been used to investigate cathodoluminescence, electron beam induced current, and diffraction of backscattered electrons.

通过扫描电子显微镜在半导体材料的扩展缺陷的全面表征

Extended defects such as dislocations and grain boundaries have a strong influence on the performance of microelectronic devices and on other applications ...

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Basics of Semiconductors

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13.6K 次观看.  Technische Universität Dresden. The optical, electrical, and structural properties of dislocations and of grain boundaries in semiconductor materials can be determined by experiments performed in a scanning electron microscope. Electron microscopy has been used to investigate cathodoluminescence, electron beam induced current, and diffraction of backscattered electrons. 

视频: Comprehensive Characterization of Extended Defects in Semiconductor Materials by a Scanning Electron Microscope

Scanning-probe Single-electron Capacitance Spectroscopy

The integration of low-temperature scanning-probe techniques and single-electron capacitance spectroscopy represents a powerful tool to study the electronic quantum structure of small systems - including individual atomic dopants in semiconductors. Here we present a capacitance-based method, known as Subsurface Charge Accumulation (SCA) imaging, which is capable of resolving single-electron charging while achieving sufficient spatial resolution to image individual atomic dopants. The use of a capacitance technique enables observation of subsurface features, such as dopants buried many nanometers beneath the surface of a semiconductor material1,2,3. In principle, this technique can be applied to any system to resolve electron motion below an insulating surface.
As in other electric-field-sensitive scanned-probe techniques4, the lateral spatial resolution of the measurement depends in part on the radius of curvature of the probe tip. Using tips with a small radius of curvature can enable spatial resolution of a few tens of nanometers. This fine spatial resolution allows investigations of small numbers (down to one) of subsurface dopants1,2. The charge resolution depends greatly on the sensitivity of the charge detection circuitry; using high electron mobility transistors (HEMT) in such circuits at cryogenic temperatures enables a sensitivity of approximately 0.01 electrons/Hz&frac12; at 0.3 K 5.

Scanning-probe single-electron capacitance spectroscopy facilitates the study of single-electron motion in localized subsurface regions. A sensitive charge-detection circuit is incorporated into a cryogenic scanning probe microscope to investigate small systems of dopant atoms beneath the surface of semiconductor samples.

扫描探针单电子电容谱

The integration of low-temperature scanning-probe techniques and single-electron capacitance spectroscopy represents a powerful tool to study the ...

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Electron Channeling Contrast Imaging for Rapid III-V Heteroepitaxial Characterization

Misfit dislocations in heteroepitaxial layers of GaP grown on Si(001) substrates are characterized through use of electron channeling contrast imaging (ECCI) in a scanning electron microscope (SEM). ECCI allows for imaging of defects and crystallographic features under specific diffraction conditions, similar to that possible via plan-view transmission electron microscopy (PV-TEM). A particular advantage of the ECCI technique is that it requires little to no sample preparation, and indeed can use large area, as-produced samples, making it a considerably higher throughput characterization method than TEM. Similar to TEM, different diffraction conditions can be obtained with ECCI by tilting and rotating the sample in the SEM. This capability enables the selective imaging of specific defects, such as misfit dislocations at the GaP/Si interface, with high contrast levels, which are determined by the standard invisibility criteria. An example application of this technique is described wherein ECCI imaging is used to determine the critical thickness for dislocation nucleation for GaP-on-Si by imaging a range of samples with various GaP epilayer thicknesses. Examples of ECCI micrographs of additional defect types, including threading dislocations and a stacking fault, are provided as demonstration of its broad, TEM-like applicability. Ultimately, the combination of TEM-like capabilities &#8211; high spatial resolution and richness of microstructural data &#8211; with the convenience and speed of SEM, position ECCI as a powerful tool for the rapid characterization of crystalline materials.

The use of electron channeling contrast imaging in a scanning electron microscope to characterize defects in III-V/Si heteroexpitaxial thin films is described. This method yields similar results to plan-view transmission electron microscopy, but in significantly less time due to lack of required sample preparation.

电子通道造影的快速III-V异质特征

Misfit dislocations in heteroepitaxial layers of GaP grown on Si(001) substrates are characterized through use of electron channeling contrast imaging ...

In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography (CT) and Light Microscopy (LM) Correlated with Scanning Electron Microscopy (SEM)

In failure analysis, device characterization and reverse engineering of light emitting diodes (LEDs), and similar electronic components of micro-characterization, plays an important role. Commonly, different techniques like X-ray computed tomography (CT), light microscopy (LM) and scanning electron microscopy (SEM) are used separately. Similarly, the results have to be treated for each technique independently. Here a comprehensive study is shown which demonstrates the potentials leveraged by linking CT, LM and SEM. In depth characterization is performed on a white emitting LED, which can be operated throughout all characterization steps. Major advantages are: planned preparation of defined cross sections, correlation of optical properties to structural and compositional information, as well as reliable identification of different functional regions. This results from the breadth of information available from identical regions of interest (ROIs): polarization contrast, bright and dark-field LM images, as well as optical images of the LED cross section in operation. This is supplemented by SEM imaging techniques and micro-analysis using energy dispersive X-ray spectroscopy.

In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography CT and Light Microscopy LM Correlated with Scanning Electron Microscopy SEM

A workflow for comprehensive micro-characterization of active optical devices is outlined. It contains structural as well as functional investigations by means of CT, LM and SEM. The method is demonstrated for a white LED which can be still be operated during characterization.

在通过X射线计算机断层扫描（CT）和与扫描电子显微镜相关光学显微镜（LM）的一个组合的LED深度分析（SEM）的

In failure analysis, device characterization and reverse engineering of light emitting diodes (LEDs), and similar electronic components of ...

Probing C84-embedded Si Substrate Using Scanning Probe Microscopy and Molecular Dynamics

This paper reports an array-designed C84-embedded Si substrate fabricated using a controlled self-assembly method in an ultra-high vacuum chamber. The characteristics of the C84-embedded Si surface, such as atomic resolution topography, local electronic density of states, band gap energy, field emission properties, nanomechanical stiffness, and surface magnetism, were examined using a variety of surface analysis techniques under ultra, high vacuum (UHV) conditions as well as in an atmospheric system. Experimental results demonstrate the high uniformity of the C84-embedded Si surface fabricated using a controlled self-assembly nanotechnology mechanism, represents an important development in the application of field emission display (FED), optoelectronic device fabrication, MEMS cutting tools, and in efforts to find a suitable replacement for carbide semiconductors. Molecular dynamics (MD) method with semi-empirical potential can be used to study the nanoindentation of C84-embedded Si substrate. A detailed description for performing MD simulation is presented here. Details for a comprehensive study on mechanical analysis of MD simulation such as indentation force, Young&#39;s modulus, surface stiffness, atomic stress, and atomic strain are included. The atomic stress and von-Mises strain distributions of the indentation model can be calculated to monitor deformation mechanism with time evaluation in atomistic level.

Probing C84-embedded Si Substrate Using Scanning Probe Microscopy and Molecular Dynamics

This paper reports the nanomaterial fabrication of a fullerene Si substrate inspected and verified by nanomeasurements and molecular dynamic simulation.

探测ç<sub&gt; 84</sub&gt; - 嵌入式硅衬底利用扫描探针显微镜和分子动力学

This paper reports an array-designed C84-embedded Si substrate fabricated using a controlled self-assembly method in an ultra-high vacuum chamber. The ...

Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction

One of the challenges in microstructure analysis nowadays resides in the reliable and accurate characterization of ultra-fine grained (UFG) and nanocrystalline materials. The traditional techniques associated with scanning electron microscopy (SEM), such as electron backscatter diffraction (EBSD), do not possess the required spatial resolution due to the large interaction volume between the electrons from the beam and the atoms of the material. Transmission electron microscopy (TEM) has the required spatial resolution. However, due to a lack of automation in the analysis system, the rate of data acquisition is slow which limits the area of the specimen that can be characterized. This paper presents a new characterization technique, Transmission Kikuchi Diffraction (TKD), which enables the analysis of the microstructure of UFG and nanocrystalline materials using an SEM equipped with a standard EBSD system. The spatial resolution of this technique can reach 2 nm. This technique can be applied to a large range of materials that would be difficult to analyze using traditional EBSD. After presenting the experimental set up and describing the different steps necessary to realize a TKD analysis, examples of its use on metal alloys and minerals are shown to illustrate the resolution of the technique and its flexibility in term of material to be characterized.

This paper provides a detailed method to characterize the microstructure of ultra-fine grained and nanocrystalline materials using a scanning electron microscope equipped with a standard electron backscatter diffraction system. Metal alloys and minerals presenting refined microstructures are analyzed using this technique, showing the diversity of its possible applications.

超细晶和纳米晶材料的表征采用透射菊池衍射

One of the challenges in microstructure analysis nowadays resides in the reliable and accurate characterization of ultra-fine grained (UFG) and ...

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and forging. Adoption of this technique is proceeding despite disagreement concerning the underlying mechanism responsible for EAD. The experimental procedure described herein enables a more explicit study compared to previous EAD research by removing thermal effects, which are responsible for disagreement in interpreting previous EAD results. Furthermore, as the procedure described here enables EAD observation in situ and in real time in a transmission electron microscope (TEM), it is superior to existing post-mortem methods that observe EAD effects post-test. Test samples consist of a single crystal copper (SCC) foil having a free-standing tensile test section of nanoscale thickness, fabricated using a combination of laser and ion beam milling. The SCC is mounted to an etched silicon base that provides mechanical support and electrical isolation while serving as a heat sink. Using this geometry, even at high current density (~3,500 A/mm2), the test section experiences a negligible temperature increase (&#60;0.02 &#176;C), thus eliminating Joule heating effects. Monitoring material deformation and identifying the corresponding changes to microstructures, e.g. dislocations, are accomplished by acquiring and analyzing a series of TEM images. Our sample preparation and in situ experiment procedures are robust and versatile as they can be readily utilized to test materials with different microstructures, e.g., single and polycrystalline copper.

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Isolating electrical and thermal effects on electrically assisted deformation (EAD) is very difficult using macroscopic samples. Metallic sample micro- and nanostructures together with a custom test procedure have been developed to evaluate the impact of applied current on the formation without joule heating and evolution of dislocations on these samples.

一种新的方法<em&gt;原位</em&gt;纳米级样品的机电表征

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and ...

All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics

The miniaturization of semiconductor devices to scales where small numbers of dopants can control device properties requires the development of new techniques capable of characterizing their dynamics. Investigating single dopants requires sub-nanometer spatial resolution, which motivates the use of scanning tunneling microscopy (STM). However, conventional STM is limited to millisecond temporal resolution. Several methods have been developed to overcome this shortcoming, including all-electronic time-resolved STM, which is used in this study to examine dopant dynamics in silicon with nanosecond resolution. The methods presented here are widely accessible and allow for local measurement of a wide variety of dynamics at the atomic scale. A novel time-resolved scanning tunneling spectroscopy technique is presented and used to efficiently search for dynamics.

We demonstrate an all-electronic method to observe nanosecond-resolved charge dynamics of dopant atoms in silicon with a scanning tunneling microscope.

全电子纳秒分辨扫描隧道显微镜: 促进单一掺杂剂电荷动力学的研究

The miniaturization of semiconductor devices to scales where small numbers of dopants can control device properties requires the development of new ...

Quantitative Atomic-Site Analysis of Functional Dopants/Point Defects in Crystalline Materials by Electron-Channeling-Enhanced Microanalysis

A novel elemental and chemical analysis scheme based on electron-channeling phenomena in crystalline materials is introduced, where the incident high-energy electron beam is rocked with the submicrometric pivot point fixed on a specimen. This method enables us to quantitatively derive the site occupancies and site-dependent chemical information of impurities or intentionally doped functional elements in a specimen, using energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy attached to a scanning transmission electron microscope, which is of significant interest to current materials science, particularly related to nanotechnologies. This scheme is applicable to any combination of elements even when the conventional Rietveld analysis by X-ray or neutron diffraction occasionally fails to provide the desired results because of limited sample sizes and close scattering factors of neighboring elements in the periodic table. In this methodological article, we demonstrate the basic experimental procedure and analysis method of the present beam-rocking microanalysis.

We provide a general outline of quantitative microanalysis methods for estimating the site occupancies of impurities and their chemical states by taking advantage of electron-channeling phenomena under incident electron beam-rocking conditions, which reliably extract information from minority species, light elements, oxygen vacancies, and other point/line/planar defects.

通过电子引导增强微分析对晶体材料中功能性多裤/点缺陷的定量原子场分析

A novel elemental and chemical analysis scheme based on electron-channeling phenomena in crystalline materials is introduced, where the incident ...

化学

A Virtual Simulation Experiment of Mechanics: Material Deformation and Failure Based on Scanning Electron Microscopy

This work presents a set of comprehensive virtual experiments to detect material deformation and failure. The most commonly used pieces of equipment in mechanics and material disciplines, such as a metallographic cutting machine and a high-temperature universal creep testing machine, are integrated into a web-based system to provide different experimental services to users in an immersive and interactive learning environment. The protocol in this work is divided into five subsections, namely, the preparation of the materials, molding the specimen, specimen characterization, specimen loading, nanoindenter installation, and SEM in situ experiments, and this protocol aims to provide an opportunity for users regarding the recognition of different equipment and the corresponding operations, as well as the enhancement of laboratory awareness, etc., using a virtual simulation approach. To provide clear guidance for the experiment, the system highlights the equipment/specimen to be used in the next step and marks the pathway that leads to the equipment with a conspicuous arrow. To mimic the hands-on experiment as closely as possible, we designed and developed a three-dimensional laboratory room, equipment, operations, and experimental procedures. Moreover, the virtual system also considers interactive exercises and registration before using chemicals during the experiment. Incorrect operations are also allowed, resulting in a warning message informing the user. The system can provide interactive and visualized experiments to users at different levels.

This work presents a three-dimensional virtual simulation experiment for material deformation and failure that provides visualized experimental processes. Through a set of experiments, users can become familiar with the equipment and learn the operations in an immersive and interactive learning environment.

力学虚拟仿真实验:基于扫描电镜的材料变形与失效

This work presents a set of comprehensive virtual experiments to detect material deformation and failure. The most commonly used pieces of equipment in ...

<meta charset="utf8"></head><body>在牙髓再治疗中单次和多次使用后 NiTi 档案中的表面缺陷

Scanning Electron Microscopic Evaluation of Surface Defects of Remover Retreatment File After Single and Multiple Uses

This study aimed to evaluate surface defects of Remover rotary Nickel-Titanium (NiTi) files after single and multiple uses in conventional endodontic retreatment procedures using scanning electron microscopy (SEM). Eighty acrylic blocks, simulating root canals with a 1.5 mm internal diameter, a 5 mm radius of curvature, and a 55&#176; curvature, were utilized. After chemomechanical preparation and obturation, 24 new Remover files (N30, 7%, L23) were randomly assigned to three groups: single use, triple use, and six uses. The files were operated at 600 rpm with a torque of 2.5 Ncm, cleaned, and sterilized after each use.
SEM analysis at magnifications of 100x, 250x, and 500x revealed surface defects, including tip deformation, microcracks, fracture, unwinding, surface pitting, and blade disruption. Deformation was observed in 75% of the files after a single use and in 100% of the files after three and six uses. Microcracks were absent after single use but appeared in 25% and 87.5% of files after three and six uses, respectively, showing a statistically significant increase (p &#60; 0.001). Surface pitting also significantly increased among groups (p = 0.004).
No fractures were observed in any group. The most common defects were tip deformation (91.7%) and surface pitting (70.8%). The findings suggest that repeated use of NiTi files significantly increases surface defects, elevating the risk of fatigue fractures. Thus, the results recommend limiting the reuse of Remover files to a maximum of 3x. Further research is needed to correlate defect types with anatomical factors and to assess file effectiveness in retreatment scenarios.

<meta charset="utf8"></head><body>去除剂再处理文件单次和多次使用后表面缺陷的扫描电镜评价

Here, we present a protocol for evaluating the surface characteristics of endodontic retreatment files after repeated use in retreatment procedures, utilizing scanning electron microscopy to identify and analyze potential surface defects.

去除剂再处理文件单次和多次使用后表面缺陷的扫描电镜评价

This study aimed to evaluate surface defects of Remover rotary Nickel-Titanium (NiTi) files after single and multiple uses in conventional endodontic ...

通过扫描电子显微镜在半导体材料的扩展缺陷的全面表征

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