硅片缺陷测试.pdf

Inline PhotoLuminescence High Quality High Speed Inline Imaging Lifetime Calibrated Inline photoluminescence measurement at any processing stage from as cut wafers to finished cells Megapixel images of full 125 or 156 mm wafers High resolution image enable defects detection around grain boundaries and of dislocations Sensitivity of low lifetime areas detection on edge and corner wafers Sensitivity of Edge isolation and shunt defects monitoring on finished cells Flexible wafer classification by either lifetime or PL intensity Effective calibration methodology Calibrated to Semilab QSS PCD or PCD lifetime PL Applications 2 26 20122 3 Photoluminescence Imaging Excitation of charge carriers is carried out by high intensity illumination Charge carriers recombination If no defects present there is a chance of radiative recombination During radiative recombination a photon is emitted which can be detected by an IR camera PL intensity is inversely proportional to defect density and impurity concentration To get quantitative results or wafer to wafer comparison calibration is needed as lifetime measurements Valence band Conduction band PL signal generation PL signal excitation defect 2 26 2012 Capabilities For As Cut Wafers 2 26 20124 Inline PL Inspection For As Cut Wafers Operation MethodOn the fly Reflection Semilab PCDCalibration Wafer Size 125x125 or 156x156 on request mm Image Size1Megapixel Resolution160 m pixel Acquisition Time 1 5 s Detectable DefectionDislocation Crack High contamination density High vacancy density MonoPolyMonocast Use Case As Cut Wafer 2 26 20125 Sensitive to defects of material Grain boundaries Dislocations Speed 250 mm s Fast acquisition1 t 1 s High resolution1 160 m px 1For full 156 mm wafers Use Case As Cut Edge Wafer 2 26 20126 Sensitive to defects of material Grain boundaries Dislocations Edge defect Speed 250 mm s Fast acquisition1 t 1 s High resolution1 160 m px 1For full 156 mm wafers Use Case As Cut Bottom Wafer 2 26 20127 Sensitive to defects of material Grain boundaries Dislocations Speed 250 mm s Fast acquisition1 t 1 s High resolution1 160 m px 1For full 156 mm wafers Use Case Monocast As Cut Wafer 2 26 20128 Sensitive to defects of material Edge contaminations Contaminations dark area High contamination density at the grain bounderies Speed 250 mm s Fast acquisition1 t 1 s High resolution1 160 m px 1For full 156 mm wafers Capabilities For Processed Wafer Finished Cell 2 26 20129 Inline PL Inspection For Process Wafer Finished Cell Operation MethodOn the fly Reflectance Semilab PCDCalibration Wafer Size 125x125 or 156x156 mm Image Size1Megapixel Resolution160 m pixel Acquisition Time 1s Detectable DefectionShunt Edge Isolation Defect Bad Finger Processed WaferFinished Cells Black Heart Sensitive to defects of processed wafer Grain boundaries Dislocations Speed 250 mm s Fast acquisition1 t 1 s High resolution1 160 m px Use Case Processed Wafer 2 26 201210 1For full 156 mm wafers Sensitive to defects of Finished cell Grain boundaries Dislocations Shunts Edge isolation defect Speed 250 mm s Fast acquisition1 t 1 s High resolution1 160 m px Use Case Finished Cells 2 26 201211 1For full 156 mm wafers Sensitive to defects of Finished cell Grain boundaries Dislocations Edge isolation defects Shunts Speed 250 mm s Fast acquisition1 t 1 s High resolution1 160 m px Use Case Finished Cell 2 26 201212 1For full 156 mm wafers Use Case Black Heart Defects 2 26 201213 Good correlation with EL result PL and PCD have the same signature One rout cause of black heart is high vacancy density PL image 1000 ADU 15000 EL image 0 ADU 20001 s6 5 PCDimage Point to point correlation within one wafer R2 99 PL Calibration Methodology 2 26 201214 Build in Semilab standard lifetime calibration module QSS PCD PCD Good correlation between PL and lifetime Coefficient may vary due to Wafer thickness Doping Resistivity Correlation of PL and Lifetime Use Case Multi crystalline Wafer 2 26 201215 Calibrated Inline PL Image 1000 ADU6500 Lifetime Map 0 12 s1 90 Use Case Mono crystalline Wafer 2 26 201216 Calibrated Inline PL ImageLifetime Map Dense dislocations defects was detected by PL Low efficiency of final cell due to dislocation defects Use Case Monocast Wafer 2 26 201217 Wafer PictureCalibrated Inline PL Image Use Case Monocast Wafer 2 26 201218 Wafer PictureCalibrated Inline PL Image Dense dislocations defects was detected by PL Low efficiency of final cell due to dislocation defects PL Classification Methodology 2 26 201219 Flexible classification methodology Could be classified by lifetime Average value standard deviation etc Could be classified by PL intensity Dark area Defect area Dark edge area etc Three groups are classified and sorted Classification was based on average lifetime of whole wafer Group A has qualified efficiency result Group C has efficiency fail issue Use Case PL Classifier 2 26 201220 Group Classifier s Final Result VocIscFFMCell A 10 61788 376678 17216 52 B0 6 10 61328 272177 33016 02 C 0 60 60688 082677 23815 47 Hardware Flexibility 21 ModelDescription PLI 200 Measurement at any processing stage from as cut wafer to finished cell Build in either QSS PCD or PCD system Megapixel image Belt transferring system option Extendibility to wafer inspection sorter ModelDescription PVS 5000 Fully automatic PL inspection system Measurement at any processing stage from as cut wafer to finished cell Build in either QSS PCD or PCD system Megapixel image Extendibility to wafer inspection sorter Flexible hardware configuration to meet all