硅片平整度知识介绍.ppt

硅片平整度知识讨论IQC 2006-4-20硅片平整度知识讨论主要内容如下：1、硅片平整度定义；2、硅片平整度测量；3、硅片平整度规范4、硅片使用中异常举例平整度SEMI 标准 关键字注释习惯用语SEMI 标准用语新SEMI 标准 关键字注释TTVGBIR Global flatness back ideal rangeTIR GFLRGlobal flatness front least-squares rangeSTIRSFQRSite flatness front least-squares rangeLTVSBIRSite flatness back ideal rangeFPDGFLD GF3DGlobal flatness front least-squares deviation Global flatness front 3 point deviationTTV(Total Thickness Variation)定义：TTV = a – b ( SEMI标准中为GBIR )说明：1.参考平面 B为Wafer背面TIR(Total Indicator Reading )定义：TIR = |a| + |b| ( SEMI标准中为GFLR )说明：1.参考平面(bf) G为距上表面所有点截距之和最小的平面；FPD(Focal Plane Deviation)定义：FPD =± Max ( |a| , |b| ) ( SEMI标准中为GFLD )说明：1. 如果|a| > |b| ，则FPD取正值；反之取负值；2.参考平面G (bf)为距Wafer上表面所有点截距之和最小的平面；Warp定义：Warp=| a | + | b |说明：1.参考平面M为距曲面Median plane 所有点截距之和最小的平面；2.不考虑重力影响；Bow定义：Bow=1/2 * ( b -f )说明：1.参考平面 W 以Wafer上三点确定，此三点组成一等边三角形2.凸的Wafer Bow值为正，凹的Wafer Bow值为负；3mm120°120°LTV(Local Thickness Variation)定义：LTVi = ai – bi i=1,2,3,4,.,n( SEMI标准中为SBIR )说明：1.参考平面B为Wafer背面；2.LTV max= Max( LTV1, LTV2,.,LTVn)STIR(Site Total Indicator Reading)定义：STIRi = | ai |+ | bi | i=1,2,3,4,.,n ( SEMI标准中为SFLR )说明：1.参考平面G i通过每一单元块的中心且平行于wafer上表面的拟合平面bf G ；2.G为距单元块上每一点截距最小的平面；3.STIR max= Max( STIR1, STIR2,., STIR n)；STIR/L- Site(Site Total Indicator Reading)定义：STIRi /L= | ai |+ | bi | i=1,2,3,4,.,n ( SEMI标准中为SFQR )说明：1.参考平面bf G i为距单元块上每一点截距最小的平面；2. STIRi /L max= Max(STIR1 /L , STIR2 /L ,., STIRn /L )；SFPD/L-Site定义：SFPD i /L= ± Max( | ai |, | bi | ) i=1,2,3,4,.,n ( SEMI标准中为SFQD )说明：1.| a | > | b | ,取正值； | a | | b | ,取正值； | a | < | b | ,取负值；2.参考平面G i通过每一单元块的中心且平行于wafer上表面的拟合平面bf G ；3. SFPD /G max= Max(SFPD 1/G , SFPD 2/G ,., SFPD n/G )SEMI StandardFQAMeasurement MethodReference SurfaceReference Plane and AreaReference Plane and AreaReference SurfaceSite Size and ArrayParameterParameterGBIRGF3RGF3DGFLRGFLDSF3RSF3DSFLRSFLDSFQRSFQDSBIRSBIDRangeRangeDeviationRangeDeviationRangeDeviationRangeDeviationRangeDeviationRangeDeviationParameterParameterParameterParameterParameterReference Plane and AreaReference Plane and AreaS-TIRS-FPDS-TIRS-FPDS-TIRS-FPDLTVS-FPDSemi用语現行 习惯用语TTVTIRFPDTIR NTVFPDFront Ref. Center Focus3pointBest FitSite Best FitBack Ref.Center FocusSite FlatnessGlobal FlatnessFrontBackBackFront3Point3Point(全面)Ideal(全面)(最小二乗法) bf Least Squares (全面)Least Squares (全面) (bf)Least Squares(site)Ideal(全面)参考面的选取 (表面 or 背面)参考平面的設定 (bf or 3pt) 又称理想平面( Flatness Quality Area )Flatness Tools Principle : Capacitance sensor (ADE)Wafertbcat=a-b-cRing Spacing局部平整度测量边缘问题Partials Inactive Site Setup局部平整度测量边缘问题Partials Active Site Setup• Green lines indicates partial sites.两种方式测量结果差异举例--- SFQD TrendChanged Measurement to Partial Sites ActiveChanging to Partial Sites Active Increased SFQD on a sample of Epi wafersInactive 0.17umActive 0.24um平整度SEMI 标准ITEMSPOLISHED WAFEREPITAXIAL WAFER1.0um Design Rule Twin-Tub CMOS0.35um Design Rule Twin-Tub CMOS0.35um Design Rule DRAM TTV(GBIR)10um----5umTIR(GFLR)------3umSFQD--<=0.5um 18x18mm<=0.23um 22x22mm<=0.35um 22x22mm BOW60um------WARP60um------SEMI STANDARD FOR 150mm (SEMI M1 AND M11)CSMC现有平整度规范举例常用硅片STIR数值举例上图为各厂家上图为各厂家STIRSTIR均值中的均值中的MAXMAX、、MEANMEAN、、MINMIN比较比较工艺过程硅片平整度变化擦片后、一次/牺牲氧化（900C）后、SIN（700C）后采用光 刻PENKIB1设备进行平整度测量，每片的平整度三次测量结论：数值差异不大 平整度有增大的趋势聚焦异常Flatness Values测量TTVTIR Best FitSFPD Best FitBow Best FitWarp Best Fit S1 Defocus5.6201.943-0.271- 0.73 6.16S2 Defocus6.9552.443-0.241-20.6142.14S3 Defocus5.2332.363+0.314-17.0035.77S233.0301.600-0.292+ 0.51 7.31S25 OK2.8681.793-0.297-17.8238.35EPI Not Proc 3.0651.801-0.224------异常与TTV相关聚焦异常Flatness Values测量SFQD Site Best Fit CurrentSBID Back RefSFLD Front Ref Best FitSF3D Front Ref 3 Point S1 Defocus-0.271-1.311-0.940-0.966S2 Defocus-0.241-1.649-1.204-1.262S3 Defocus+0.314-1.502-1.151-1.184S23-0.292-0.757-0.951-1.012 S25 OK -0.297-1.043-0.940-1.035EPI Not Proc-0.224-0.565-0.744-0.730Defocus does not correspond to site flatness, such as SFQD,SBID, SFLD, and SF3D.。