基于扫描电镜的电子束曝光系统Raith

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图形发生器
Beam blanker
Beam blanking
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Faraday圆筒——测电流
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工作方式 －高斯束、矢量扫描、固定工作台
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Elphy plus主控制界面
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曝光图形的制作
曝光之前，必须先知道曝什么！
图形格式：.CSF或者.GDS 常用软件：elphy plus －GDSII database
SEM)
Acceleration voltage:200 V 30kV Resolution:1.5nm at >10kV, 2.5nm at 1kV Electron spot ~ 1nm, Resolution ~ 1nm STEM within SEM!! + CL detector
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电子发射枪
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电子透镜原理
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• Electron gun produces beam of monochromatic electrons.
• First condenser lens forms beam and limits current ("coarse knob").
L－edit AutoCAD 等等
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增 加 图 层
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选 定 图 层
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选 定 图 层
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显 示 绘 图 格 点
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改 变 绘 图 格 点 间 距
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选 用 画 笔
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曝光图形设计注意事项
• 最小尺寸：线宽、间距（考虑临近效应） • 对准标记要适合（多用十字） • 需要曝光的图形要远离对准标记 • 两层之间的对准要留容错 • 注意曝光的顺序 • 注意图形交叠，特别是场拼接处的图形
• Production of seco精n品d文a档ry electrons is topography related. Only secondaries near surface (<10 nm) exit sample.
如何生成二次电子像
• Secondary electrons are generated by the interaction of the incident electron beam and the sample. The secondary electrons emerge at all angles. These electrons gathered by electrostatically attracting them to the detector. Knowing both the intensity of secondary electrons emitted and position of the beam, an image is constructed electronically.
• Condenser aperture eliminates high-angle electrons.
• Second condenser lens forms thinner, coherent beam ("fine knob" ).
• Objective aperture (usu. userselectable) further eliminates high-angle electrons from
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基于扫描电镜的电子束曝光系统 Raith GmbH Elphy plus
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主要内容
• 扫描电子显微镜介绍 • Raith电子束曝光系统 • 电子束曝光图形制作 • 曝光参数 • 对准操作 • 纳米器件制作的主要步骤
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XL 30 S FEG (a top performing field emission
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beam.
• Beam "scanned" by deflection coils to form image.
• Final objective lens focuses beam onto specimen.
• Beam interacts with sample and outgoing electrons are detected.
incident e- beam
beam location
emitted e-
secondary edetector
signal intensity
Hale Waihona Puke Baidu
~精+品12文,0档00 V
Raith电子束曝光系统
曝光精度 < 30 nm , 器件套刻精度~ 50精n品m文档
控制系统界面
Beam blanker Amplifier
escape
• Caused by incident electron passing "near" sample atom and ionizing an electron (inelastic process).
• Ionized electron leaves sample with very small kinetic energy (5eV) and is called "secondary electron". (Each incident electron can produce several secondary electrons.)
X-rays Auger e–
Cathodaluminescence Secondary e–
Inelastically Scattered e–
Elastically Scattered e–
Unscattered e–
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二次电子的形成
MORE secondary e–
escape
FEWER secondary e–
• Detector counts electrons at given location and displays intensity.
• Process repeated until scan
is finished (usu. 30
frames/sec).
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电子相互作用
Incident e– Backscattered e–