基于掃描電鏡的電子束曝光系統(tǒng)Raith全解.ppt

1、基于掃描電鏡的電子束曝光系統(tǒng)Raith GmbH Elphy plus,主要內(nèi)容,掃描電子顯微鏡介紹 Raith電子束曝光系統(tǒng) 電子束曝光圖形制作 曝光參數(shù) 對準(zhǔn)操作 納米器件制作的主要步驟,XL 30 S FEG(a top performing field emission 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,電子發(fā)射槍,電子透鏡原理,Electr

2、on gun produces beam of monochromatic electrons. First condenser lens forms beam and limits current (coarse knob). Condenser aperture eliminates high-angle electrons. Second condenser lens forms thinner, coherent beam (fine knob ). Objective aperture (usu. user-selectable) further eliminates high-an

3、gle electrons from 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. Detector counts electrons at given location and displays intensity. Process repeated until scan is finished (usu.

4、30 frames/sec).,Cathodaluminescence,Secondary e,Backscattered e,Incident e,Elastically Scattered e,Inelastically Scattered e,Unscattered e,X-rays,Auger e,電子相互作用,Caused by incident electron passing near sample atom and ionizing an electron (inelastic process). Ionized electron leaves sample with very

5、 small kinetic energy (5eV) and is called secondary electron.(Each incident electron can produce several secondary electrons.) Production of secondary electrons is topography related. Only secondaries near surface (10 nm) exit sample.,FEWER secondary e escape,MORE secondary e escape,二次電子的形成,如何生成二次電子

6、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

7、the beam, an image is constructed electronically.,Raith電子束曝光系統(tǒng),曝光精度 30 nm , 器件套刻精度 50 nm,Beam blanker,圖形發(fā)生器,Beam blanker Amplifier,控制系統(tǒng)界面,Beam blanking,Faraday圓筒測電流,工作方式高斯束、矢量掃描、固定工作臺,Elphy plus主控制界面,曝光圖形的制作,圖形格式：.CSF或者.GDS,常用軟件：elphy plus GDSII database Ledit AutoCAD 等等,曝光之前，必須先知道曝什么！,增加圖層,選定圖層,選定圖

8、層,顯示繪圖格點,改變繪圖格點間距,選用畫筆,曝光圖形設(shè)計注意事項,最小尺寸：線寬、間距（考慮臨近效應(yīng)） 對準(zhǔn)標(biāo)記要適合（多用十字） 需要曝光的圖形要遠(yuǎn)離對準(zhǔn)標(biāo)記 兩層之間的對準(zhǔn)要留容錯 注意曝光的順序 注意圖形交疊，特別是場拼接處的圖形,d,曝光中的主要操作對準(zhǔn),1、源漏電極要壓在納米管上 2、柵電極要蓋在源漏之間,難點：很多地方不能看！,對準(zhǔn)調(diào)節(jié),曝光之前，必須先知道在哪里曝光！,掃描電鏡的坐標(biāo) （x,y）,曝光系統(tǒng)定義的坐標(biāo) （u,v）,兩套坐標(biāo)的刻度校準(zhǔn),標(biāo)準(zhǔn)樣品,三點校正確定u、v坐標(biāo),（1.0,0） (1.5,0) (1.5,0.5),第一次三點校正,第二次三點校正,（1.07,1.05）,（1.43,1.05）,（1.45,1.43）,曝光參數(shù)設(shè)置掃描電鏡,加速電壓 如：20kV Spot size 工作高度選擇,曝光參數(shù)設(shè)置Elphy plus,圖層選擇 電流密