materialfortheimplementationofPDMA.Copperisselectedasthematerialofthetopconductor(thebridge).Copperisalsoahighconductivitymetalanditsprocessingiscompatiblewiththegoldbottomconductorduringthefabrication.SiliconoxideandnitridearegooddielectricmaterialsavailableinsiliconICprocess.However,theyarenotsuitableforverticalplanarcoilinductorsduetohighinternalstressandpooradhesiononmetalsurface.CYTOPamorphouotprintsandthusoccupymuchsmallersubstratespace.PLASTICDEFORMATIONMAGNETICASSEMBLY(PDMA)Fig.AschematicillustrationofaPlasticDeformationMagneticAssemblyprocess(PDMA)PDMAisthekeytechnologytorealizetheverticalplanarcoilinductors.Adetaileddiscussionofthisassemblyprocesswillbepresentedinotherpublications.AbriefintroductionofPDMAisgivenbelowbyusingacantileverbeamasanexample.Notethattheregionnearthefixedendisintentionallymademoreflexible.First,acantileverbeamwithapieceofmagneticmaterialattachedtoitstopsurfaceisreleasedfromthesubstratebyetchingawaythesacrificiallayerunderneath(Fig.(a)).Next,amagneticfieldHextisapplied,themagneticmaterialpieceismagnetizedandthecantileverbeamwillberotatedoffthesubstratebythemagnetictorquegeneratedinthemagneticmaterialpiece(Fig.(b)).Ifthestructureisdesignedproperly,thisbendingwillcreateaplasticdeformationintheflexibleregion.Thecantileverbeamwillthenbeabletoremainatacertainrestangle(φ)abovethesubstrateevenafterHextisremoved(Figure(c)).Byusingductilemetal(e.g.gold)intheflexibleregion,agoodelectricalconnectionbetweentheassembledstructureandthesubstratecanbeeasilyachieved,whichissuitableforRFapplications.Aftertheverticalassembly,thestructurescanbefurtherstrengthenedandthemagneticmaterialcanberemovedifnecessary.Ifthemagneticfieldisappliedglobally,thenallthestructuresononesubstratecanbeassembledinparallel.DESIGNANDFABRICATIONThecorestructureoftheverticalplanarcoilinductorisidenticaltotheconventionalhorizontalone,whichconsistsoftwometallayersandonedielectriclayerbetween.Asageneralrule,highconductivitymetalandlowlossdielectricmaterialshouldbeused.Inadditiontothisrequirement,thestructureoftheinductorshouldfacilitatetheimplementationofPDMA.Theverticalplanarcoilinductorutilizesone-portcoplanarwaveguide(CPW)configurationwithtestpads(Ground-Signal-Ground)withapitchofμm.Thethreetestpadsalsoserveastheanchoroftheverticalinductorsonthesubstrate..MaterialConsiderationGoldisusedasthematerialforthebottomconductor(thecoil).Goldisaductilematerialwithhighconductivity.ItisanidealplasticdeformationmaterialfortheimplementationofPDMA.Copperisselectedasthematerialofthetopconductor(thebridge).Copperisalsoahighconductivitymetalanditsprocessingiscompatiblewiththegoldbottomconductorduringthefabrication.SiliconoxideandnitridearegooddielectricmaterialsavailableinsiliconICprocess.However,theyarenotsuitableforverticalplanarcoilinductorsduetohighinternalstressandpooradhesiononmetalsurface.CYTOPamorphou硅和氮化物是硅集成电路中理想绝缘材料。但是它们不适合于直立平面线圈感应器,因为它们内应力太强,并且与金属表面结合力差。CYTOP(氟化塑料光纤)非晶态聚合物是经比较挑选出来用于直立感应器中隔离物质。CYTOP电特性与Polyimide(聚酰亚胺)和Telfon(铁氟龙)相类似。但它有比较好与金属表面粘附性和化学稳定性。为了实现PDMA,将Permalloy(铁镍合金)电镀于金和铜结构表面。Permalloy层用来为PDMA提供必要磁力和感应器结构在竖直位置是足够硬度。图所示为直立平面线圈感应器PDMA装配过程和制作过程示意图。.制作过程整个制作和装配过程如图所示。这里基底是表面涂有.μm厚氮化物硅片。制作步骤如下:(a)沉积一层厚为.μm二氧化硅作为PDMA牺牲层。(b)在基底上沉积一层.μm厚金(下面带有一层牺牲层),刻蚀成感应器底部核心材料(线圈)。(c)在金上面溅射一层厚为.μmCYTOP薄膜,作为隔离物。(d)沉积一层.μm厚铜作为感应器顶部核心材料(架桥)。(e)在金和铜表面电镀一层μm厚Permalloy。(f)刻蚀氧化牺牲层,并将感应器结构从基底释放。(g)通过PDMA将感应器整个结构装配到竖直位置。实验检测和测量结果直立平面线圈感应器制作中S参数通过一个℃计算机分析器从MHz测量到GHz。S第一次测量是在PDMA过程之前,当感应器还在硅基底上时。接下来感应器被装配到竖直位置后,S被重复测量。感应器S参数与在耐热玻璃基底上设计结构是一样,S都要被测量以用来对照比较。图a所示为平面线圈感应器经过PDMA前和后对S模拟和测量结果史密斯图。B为在玻璃基底上设计制作一个同样感应器S模拟和测量结果史密斯图。这两个感应器感应系数为.nH。图a显示了平面线圈感应器S参数模拟和测量结果。感应器上出现探通术试验衬垫是被镶嵌在里面。图b显示了在耐热玻璃上设计制作感应器S参数模拟和测量结果。这种试验衬垫不是被镶嵌,因为这种感应器基底是玻璃,而且镶嵌影响几乎没有。模拟数据是通过一个关于平面线圈感应器小型电路模型而获得。从S参数模拟和测量中萃取作为频率函数品质因素Q如图所示。当平面线圈感应器在硅基底上是,它有一个值为.峰值因素Q,自共振频率为GHz。当感应器经PDMA过程而在竖直位置时,峰值因素Q增大到,自共振频率超过了GHz,这个值接近那些在玻璃基底上感应器。对于在硅基底上平面线圈感应器结构(装配前),一个巨大绝缘电容器和一个高频率基底电阻占支配地位,这就导致自共振频率大约为GHz。一旦感应器被装配到竖直位置,基底损失和电容器将被有效移走,这样就改进了感应器表面性能。而且,频率远低于GHz(这里忽略基底影响),这样玻璃基底和硅基底感应器就象预期那样测量结果完全一致。讨论)在这篇文章中,氧化物被当作PDMA中牺牲层材料。有时候,氧化物也被当作是在同一块基底上集成电路装置绝缘物质,因此不能被移动。在这种情况下,氧化物牺牲层可以被其他物质取代,例如照片底版。)为了测量简便,直立平面线圈感应器测量在PDMA之后不能再加强。但是感应器结构在PDMA之后可以通过不同方法来加强(如涂覆聚对二甲苯)以达到必要硬度和耐磨度。)当直立平面线圈感应器Q因素可以在制作过程中通过涂一层较厚金属层来改进时候,实验也就可以试着去探究一些不同方法来加厚和加强经PDMA装配后在竖直位置平面线圈感应器金属层。结论直立平面线圈感应器已经通过一种新型三维装配方法——PDMA实现了。直立平面线圈感应器较之传统感应器主要有两个优点:即它占用非常小基底空间,并且有较少基底损失和寄生现象;这种直立平面线圈感应器制作和装配过程与标准集成电路制作过程相一致,因此它适合于各种射频集成电路系统。参考文献[]C.P.Yue,S.S.Wong,硅片上螺旋感应器物理模型.电气和电子工程师协会译.电子装置,,():-.[]M.Ozgur,M.Zaghloul,MGaitan,高品质因素QCMOS微机械感应器.电气和电子工程师协会关于电路和系统国际研讨会会议记录,,:-.[]B.K.Kim,B.K.Ko,K.Lee,单片电路平面射频感应器和表面性能可与那些砷化镓单片微波集成电路相比较硅片上波导结构.IEDM工学院摘要,,-.[]J.B.Yoon,C.H,Han,E.Yoon,C.K.Kim,为射频单片微波集成电路而应用一种新型技术制作一种高性能三维片上感应器.电气和电子工程师协会,微波理论和技术协会摘要,,-.[]D.Young,V.Malba,J.Ou,A.Bernhardt,B.Boser,高性能三维线圈感应器单片集成电路在无线通信中应用.IEDM工学院摘要,,-.[]J.B.Yoon,B.K.Kim,C.H.Han,E.Yoon,K.Lee,C.K.Kim,高性能电镀螺线管型综合感应器-利用简单三维表面显微机械加工技术射频应用.IEDM工学院摘要,,-.otprintsandthusoccupymuchsmallersubstratespace.PLASTICDEFORMATIONMAGNETICASSEMBLY(PDMA)Fig.AschematicillustrationofaPlasticDeformationMagneticAssemblyprocess(PDMA)PDMAisthekeytechnologytorealizetheverticalplanarcoilinductors.Adetaileddiscussionofthisassemblyprocesswillbepresentedinotherpublications.AbriefintroductionofPDMAisgivenbelowbyusingacantileverbeamasanexample.Notethattheregionnearthefixede中文字DevelopmentofMEMSVerticalPlanarCoilInductorsThroughPlasticDeformationMagneticAssembly(PDMA)JinghongChen*,JunZou**,ChangLiu**andSung-Mo(Steve)Kang***AgereSystems,Holmdel,NJDepartmentofElectricalandComputerEngineering,UniversityofIllinoisatUrbana-Champaign,Urbana,ILJackBaskinSchoolofEngineering,UniversityofCalifornia,SantaCruzABSTRACTThispaperpresentstheresultsofthedevelopmentofaverticalplanarcoilinductor.Theplanarcoilinductorisfirstfabricatedonsiliconsubstrateandthenassembledtotheverticalpositionbyusinganovel-Dimensionalbathscaleself-assemblyprocess(PlasticDeformationMagneticAssembly(PDMA)).Inductorsofdifferentdimensionsarefabricatedandtested.TheS-parametersoftheinductorsbeforeandafterPDMAaremeasuredandcompared,demonstratingsuperiorperformanceduetoreducedsubstrateeffectsandalsoincreasedsubstratespacesavingsfortheverticalplanarcoilinductors.KeywordsMEMS,planarcoilinductor,qualityfactor,PDMA,resonancefrequency.INTRODUCTIONWiththedevelopmentofintegratedwirelesscommunicationsystems,on-chipinductorswithsatisfactoryperformance(enoughqualityfactorandselfresonantfrequency)arerequired.However,theconventionalplanarcoilinductorsuffersfromsubstratelossesandparasiticssinceitisdirectlyfabricatedontoconductivesubstrateoveraverythindielectriclayer[].Inrecentyears,muchefforthasbeenmadetoimprovetheperformanceofplanarcoilinductors.Metalmaterialswithhigherconductivityorthickermetallayersareutilizedtodecreasetheresistanceofthecoil.Meanwhile,differentmethodsareproposedtoreducethesubstratelossandparasitics,includingremovingthesubstrateunderneaththeinductor[],applyingathickpolymidelayertoseparatetheinductorfartherawayfromthesubstrate[],etc.Morerecently,planarcoilinductorslevitatedabovethesubstratearerealizedusingasacrificialmetallicmode(SMM)process[].-Dimensionalsolenoidon-chipinductorsdevelopedbyusing-Dlaserlithographyorsurfacemicromachiningtechnologyhavealsobeendemonstrated[,].Thispaperreportsverticalplanarcoilinductorsdevelopedbyusinganovel-Dself-assemblyprocess-PlasticDeformationMagneticAssembly(PDMA).Experimentalresultsshowthattheverticalplanarcoilinductorsufferslesssubstratelossandparasiticsthantheconventionalhorizontalcounterparts,andthuscanachieveahigherquality(Q)factorandself-resonantfrequency.Anothermajoradvantageoftheverticalinductorsisthattheyhavealmostzerofootprintsandthusoccupymuchsmallersubstratespace.PLASTICDEFORMATIONMAGNETICASSEMBLY(PDMA)Fig.AschematicillustrationofaPlasticDeformationMagneticAssemblyprocess(PDMA)PDMAisthekeytechnologytorealizetheverticalplanarcoilinductors.Adetaileddiscussionofthisassemblyprocesswillbepresentedinotherpublications.AbriefintroductionofPDMAisgivenbelowbyusingacantileverbeamasanexample.Notethattheregionnearthefixedendisintentionallymademoreflexible.First,acantileverbeamwithapieceofmagneticmaterialattachedtoitstopsurfaceisreleasedfromthesubstratebyetchingawaythesacrificiallayerunderneath(Fig.(a)).Next,amagneticfieldHextisapplied,themagneticmaterialpieceismagnetizedandthecantileverbeamwillberotatedoffthesubstratebythemagnetictorquegeneratedinthemagneticmaterialpiece(Fig.(b)).Ifthestructureisdesignedproperly,thisbendingwillcreateaplasticdeformationintheflexibleregion.Thecantileverbeamwillthenbeabletoremainatacertainrestangle(φ)abovethesubstrateevenafterHextisremoved(Figure(c)).Byusingductilemetal(e.g.gold)intheflexibleregion,agoodelectricalconnectionbetweentheassembledstructureandthesubstratecanbeeasilyachieved,whichissuitableforRFapplications.Aftertheverticalassembly,thestructurescanbefurtherstrengthenedandthemagneticmaterialcanberemovedifnecessary.Ifthemagneticfieldisappliedglobally,thenallthestructuresononesubstratecanbeassembledinparallel.DESIGNANDFABRICATIONThecorestructureoftheverticalplanarcoilinductorisidenticaltotheconventionalhorizontalone,whichconsistsoftwometallayersandonedielectriclayerbetween.Asageneralrule,highconductivitymetalandlowlossdielectricmaterialshouldbeused.Inadditiontothisrequirement,thestructureoftheinductors 中文2800字DevelopmentofMEMSVerticalPlanarCoilInductorsThroughPlasticDeformationMagneticAssembly(PDMA)JinghongChen*,JunZou**,ChangLiu**andSung-Mo(Steve)Kang***AgereSystems,Holmdel,NJ07733DepartmentofElectricalandComputerEngineering,UniversityofIllinoisatUrbana-Champaign,Urbana,IL61801JackBaskinSchoolofEngineering,UniversityofCalifornia,SantaCruzABSTRACTT