0.35μm垂直溝道功率芯片背金工藝優(yōu)化和缺陷改善

1、上海交通大學(xué)碩士學(xué)位論文0.35μm垂直溝道功率芯片背金工藝優(yōu)化和缺陷改善姓名：劉瑜申請學(xué)位級別：碩士專業(yè)：軟件工程指導(dǎo)教師：程秀蘭20081201V0.35mUMOSFETBacksideProcessAnalysisImproveAbstractBacksidemetalprocessisthemostimptantstepofUMOSFETprocess.InthetraditionalbacksidemetalprocessIC

2、earlyfailurealwayshappensbecauseoftheunstabeleadhesiveabilitybetweenbacksidemetalwaferbacksidewhichiscausedbysomereasonssuchasoverbacksidegrindingsurfaceroughnessmismatchmonolayermetalevapationetc.Indertoimprovetheyieldt

3、hereliabilitythenewwaferprocessbaselineofbacksideroughnessmetalevapationissetupallkindsofdefectsolvingmethodsisofferedinthepaper.Firstlyfthebacksidewaferroughnessthetwodifferentetchingsolutionsareresearched:theacidsoluti

4、ontheKOHone.Intheacidsolutionthemostappropriatevolumeratioof33%HF70%HNO3is7:1addwaterby10%whichoffersthebestroughnesswafersurfaceeasycontroletchratefthemassproduction.IntheKOHoneafter15minutesreactioninthe30%KOHsolutiont

5、hewafergetsthereasonablesurfaceconditionwhichissuitablefthenextmetalevapationstep.it’sprovedthattheacidsolutionisbetterthantheKOHoneinthemassproductionbasedonlotsofexperimentrawdata.Secondlythebacksidemetalevapationproce

6、ssparametersareoptimized.Themultilayermetal(TiNiAg)systemised.Thewaferhasbetterbacksidemetaladhesiveabilityafterpreheatedto200℃thantheonewithoutthat.Themetalsurfaceparticleproblemisbasicallysolvedbyaddingthemetalpremolte

7、ntime(1MinasTi7MinasNi3MinasAg).Atlastthecausesofsomedefectssuchaswaferbendingfrontsidediscolbacksidemetalpeelingsareanalyzedthecrespondingsolvingmethodsaresummarized.Acompleteseriesflowofbacksidemetalisfinalizedinthispa