ESC基础培训20100811-1

ESC基础培训第1页共31页ElectrostaticChuckBasic.................................................................................................................2CoulombicChuck.....................................................................................................................2Johnsen-RahbekChuck.............................................................................................................4BipolarE-chuckchuckingscheme............................................................................................6BipolarE-chuckchuckingscheme............................................................................................7BipolarE-chuckdechuckingscheme........................................................................................9BipolarE-chuckSchematics...................................................................................................10BipolarE-chuckOperationScheme........................................................................................10MonopolarE-chuck.................................................................................................................12MonopolarE-chuckSchematics.............................................................................................13LowTempCeramicPuck........................................................................................................15LowTempCeramicPuck:Embossment.................................................................................15LowTempCeramicPuck........................................................................................................16LowTempE-chuckPuck:Electrodes.....................................................................................17LowTempE-chuck.................................................................................................................18InterfaceBox...........................................................................................................................20VoltageonTerminals...............................................................................................................21CrAssembly............................................................................................................................21FilterAssembly.......................................................................................................................22RFCableAssembly.................................................................................................................23RFCableAssembly.................................................................................................................25BipolarE-chuckPowerSupply...............................................................................................25TCandTCAmplifier..............................................................................................................27PowerSuppliesConfiguration................................................................................................27SurfaceContamination............................................................................................................28ESC基础培训第2页共31页ElectrostaticChuckBasicLuChiangLiang7/25/2010CoulombicChuckCoulombicforceoncapacitorε:alumina8.5;quartz3.9;PTFE2.1dvE+-+图1.库仑原理图示ESC原理是很简单的，依靠静电引力将硅片吸引在ESC上。静电引力即库仑力，大小受到距离及介质影响，也与电压相关。Wherearethecharges?F=½εε₀AE²=⅟₂εε₀A(V²/d²)E=V/dESC基础培训第3页共31页Monopolarchuck:thechuckingvoltageapplytothewaferthroughthechamberplasmavd+-EFwaferPlasma图2.单极ESC原理示意图单极ESC形成库仑力需要借助Plasma，从而导通Wafer与腔室壁，形成回路，类似电容充电。因此单极ESC与Wafer形成库仑力需要一定的外部条件。Bipolarchuck:equivalenttotwocapacitorsinseriesd+-vAB图2.双极ESC原理示意图双极ESC相当于两个电容的串连，无需借助外界条件，存在Wafer，加载ESCDC，即形成静电引力，从而吸附Wafer。ABW图3.双极ESC电路等效图ESC基础培训第4页共31页Canawaferwithaglasscarrierbechucked?0.5mm0.5mmGlassAlNwafer图4.特殊硅片Chucking原理示意图特殊形式硅片，例如背面加载一层玻璃的硅片（TSV玻璃Wafer）也是可以形成静电引力的，但形成库仑力的几个要素都需要重新考虑，比如间距、介质等都需要考虑玻璃的因素而改变。另外，TSV玻璃会导致硅片变形，影响ChuckingForce非常严重。Johnsen-RahbekChuck•Lowresistivitypuck•JRcurrentmustpresent•RgRe,thereforeVgVeDdVVeVgIj图5.JR型E-Chuck原理示意图ESC基础培训第5页共31页VRgReIj图5.JR型E-Chuck电路等效图JR型E-Chuck原理是20世纪中期发展的，两个物质相接触，即使双方平整度很高，但真正接触的表面也是点接触。假如两物体接触面间有电压，例如硅片和ESC表面，且认为ESC材质为低电阻率材料，且存在电流，则可认为接触点间电阻率明显高于ESC内部电阻，因此两物体间电压基本被分压在接触面上。•Fieldemissiontakeplace•Wherearethecharges?•FieldemissionsaturationEf+-+-Ef+-+---++E图5.JR型E-Chuck微观结构原理图JR电流在硅片背面与Echuck正面的接触点形成。在非接触点电荷无法移动，形成了静电引力。Eg=E-EfFj~Eg²=Vg²/d²ESC基础培训第6页共31页FVCoulombicJR图6.JR型与库仑型E-Chuck引力与电压关系比较图JR型ESC比较大的一个特点是低电压状态下，能够产生比较大的引力。•Sensitivetoparticles•Howaboutthewaferwithglasscarrier?因为JR型引力形成主要集中在接触点，因此对距离因素比库仑型ESC敏感。因此假如存在Particle，则JR型ESC表现的更敏感。也因为此因素，导致特殊硅片（硅片背面有玻璃）无法使用JR型ESC。BipolarE-chuckchuckingschemePowersupplymustbefloatingWithDCbiaspresentingduringprocessing,onesidegroundedpowersupplycausesunbalancedchuckingforceAB图7.双极ESC错误连接方式示意图1ESC基础培训第7页共31页如上图接地是不行的，假如接地，则RF无法起作用。DCBAB-100v500v600v-100v图8.双极ESC错误连接方式示意图2如上图接地也是不行的，因为硅片受到RFBias影响，A、B两端相对于硅片的电压值绝对值不相等，因此引力也不相同。DCB图9.双极ESC正确连接方式示意图双极ESC，