TEA Systems Products Critical Feature and Process Tuning Software Weir PW Weir PSFM Calibration Weir PSFM Fixed-Focus 65 Schlossburg St. Alburtis, PA (+1) LithoWorks Weir DM Weir DMA Ver: 19-Dec-2005

TEA Systems 2006TEA Systems Products 2 OutlineOutline Products from TEA Systems Products from TEA Systems – Weir PW – LithoWorks PEB – Weir PSFM Calibration – Weir PSFM Fixed Focus – Weir DM and Weir DMA Product Features Applications –Addressed by each product System Requirements License Basis Sample Wafer Plots Products from TEA Systems Products from TEA Systems – Weir PW – LithoWorks PEB – Weir PSFM Calibration – Weir PSFM Fixed Focus – Weir DM and Weir DMA Product Features Applications –Addressed by each product System Requirements License Basis Sample Wafer Plots

TEA Systems 2006TEA Systems Products 3 Modeled Analyses for the Semiconductor Process Weir PW Process Windows and much more. Critical feature,overlay, registration,electrical and film models for simulator calibration, process setup, control and characterization LithoWorks PEB Post Exposure Bake and other thermal studies Correlate On-Wafer and Sensarray temperature data to Weir PW analyses for a true analysis of thermal uniformity. IsoFocal Analysis PEB Thermal Energy vs Resist

TEA Systems 2006TEA Systems Products 4 Modeled Analyses for the Semiconductor Process Weir PSFM Calibration Phase Shift Focus Monitor and other linear of exposure-tool focus to specialized test structures. Works with Benchmark PSFM, CANON Zspin, AMD Phase-Grating, ASML Focal, Toshiba Phase Gratings, End-of-Line Shortening and other reticle patterns Models the calibration-derived focal-plane of the exposure tool to derive reticle and tool focus budget. Weir PSFM Fixed Focus Analysis of full-field, wafer and lot focus-uniformity data. Use Weir PSFM Calibration templates to convert measured offset data to Focus Model the flatness of films, wafers, reticles, reticle scanners and lens perturbations. PSFM Calibration Focus Uniformity

TEA Systems 2006TEA Systems Products 5 Modeled Analyses for the Semiconductor Process Weir DM Daily Monitor, two-click automation Any Weir PW or PSFM analysis using user-created Macros Trend charts, password protection, graphic displays Weir DMA Daily Monitor Automated External program-callable Macros Automated alarms and output User selected output formats and variables Weir DM Macro Setup Interface

TEA Systems 2006TEA Systems Products 6 Running Weir DM The Weir DM is a “stand-alone” program that can also be called from the Weir Engineering interface. The analysis for a calibration uses the layout specified in the template. Current DM Templates Files in the data directory. Sorted alphabetically. Starts the calibration. “One-Click” Analysis pre-selected templates in drop- down listings Data files, sorted and pre-selected in a drop-down listing.

TEA Systems 2006TEA Systems Products 7 Astigmatism Trend Chart on Weir DM Astigmatism, also sensitive to lens heating, is shown to settle after the 8 th wafer.

TEA Systems 2006TEA Systems Products 8 Outline: Product Features Products from TEA Systems General Product FeaturesGeneral Product Features – Data Import – Graphics Features – 2D Graphics – 3D Graphics – General Analyses – Data Tools – Retention & Reporting Applications –As addressed by each product System Requirements License Basis Products from TEA Systems General Product FeaturesGeneral Product Features – Data Import – Graphics Features – 2D Graphics – 3D Graphics – General Analyses – Data Tools – Retention & Reporting Applications –As addressed by each product System Requirements License Basis

TEA Systems 2006TEA Systems Products 9 Data Import Features Import ANY metrology –If we don’t have the import now, we will create it Focus-Exposure excel spreadsheets Overlay, film-thickness, profile, Cdsem, electrical test, etc. Open data format –Microsoft Excel Workbooks A unique Weir Workbook is created for each dataset Any number of variables Any size dataset Weir imports data from any ASCII, Binary or database. After import, data is converted into a standard Weir format Excel Workbook. Workbook Stores –Intermediate analysis data, –analysis reports, –Graphics –Derived datasets HTML delivery –Weir Worksheets can be saved as HTM or HTML files for internet display Weir imports data from any ASCII, Binary or database. After import, data is converted into a standard Weir format Excel Workbook. Workbook Stores –Intermediate analysis data, –analysis reports, –Graphics –Derived datasets HTML delivery –Weir Worksheets can be saved as HTM or HTML files for internet display

TEA Systems 2006TEA Systems Products 10 Graphics Features Drill-down graphics Any graphic: –Easy user modification Mouse selected graphics –View sub-plots –Save to spreadsheet data from sub-sections –Cull specific data points/sites or areas of data. Single-click access to graphs, sub-graphics, data selection and culling.

TEA Systems 2006TEA Systems Products 11 Viewing variations across wafer diameter Use mouse to drag and outline a section. Plot graphic by x column position Notice astigmatism and how it increases at wafer’s edge. Xfocus Yfocus and Average

TEA Systems 2006TEA Systems Products 12 Graph Editor Graphic interface modification Point-click adjustments Graphs are mouse sensitive to show and highlight individual points

TEA Systems 2006TEA Systems Products 13 2D Graphs Histograms –1 & 2 variable XY Plots –Line and scatter plots –BoxPlots, Fitted Curves and notes can be added to any plot BoxPlots –Can be added to ANY XY plot Population Density Plots Field & Wafer Contour Radial Variation Range Plots 1D and 2D Vector Plots Variable Covariance plots Plus all Excel –based graphics Raw Photoresist Thickness from Ellipsometer

TEA Systems 2006TEA Systems Products 14 3D Graphs Field 3D surface graphics General response surface graphics

TEA Systems 2006TEA Systems Products 15 General Analyses Plots and statistics –For Raw, Modeled and Residual data. Reticle data at true(4x) and final (1x) size –Mask Error Function (MEF) plotting –Removal of Reticle data from wafer for true process response Optimum or “Best Focus” –From PSFM and other specialty reticles –From variable Feature profiles for reticle design & simulator validation Automated Precision & Error Budget calculation Automated variable Covariance

TEA Systems 2006TEA Systems Products 16 Data Tools View raw, modeled and residual data Model any wafer, field,lens, slit and scan systematic errors –For any variable –View individual wafer, field, slit,etc modeled, residual data Multiple field models –Weir custom and scanner vendor emulated View data as astigmatic, average, max/min data variations. –Field Mean, max, minimum, MinMax, IFD, Range MEF etc. Stepper as well as scanner oriented models –Also hotplate, etch symmetric and asymmetric models Exposure Layouts –Across wafer & Lot variations for Focus, Dose, Numeric Aperture, Partial Coherence, Scan Direction are stored with data. –Layouts can be imported from the data –Graphic, mouse-driven utility for easy manual entry of the layout –Layout library is maintained for easy updating of new datasets with a single click of the mouse

TEA Systems 2006TEA Systems Products 17 Data Retention Data is imported and stored in an open format –Easily adapted to other software analyses or user analysis using Excel – native tools Data is stored in the same workbook for: –Raw data –Recipe and measurement notes –Site locations –Analysis reports and graphics –All intermediate modeling surfaces –All calculated data surface

TEA Systems 2006TEA Systems Products 18 Outline: Applications Products from TEA Systems Product Features Applications (Automated by Weir DMA) –Exposure Tool setup & Characterization –Photomask Process Control –Reticle RET Qualification –Thermal Process setup –Metrology validation –LER, ARC and Resist evaluation –Process Setup & Control –Modeled Production Gating –Simulation validation –Focus optimization System Requirements License Basis Products from TEA Systems Product Features Applications (Automated by Weir DMA) –Exposure Tool setup & Characterization –Photomask Process Control –Reticle RET Qualification –Thermal Process setup –Metrology validation –LER, ARC and Resist evaluation –Process Setup & Control –Modeled Production Gating –Simulation validation –Focus optimization System Requirements License Basis

TEA Systems 2006TEA Systems Products 19 Exposure Tool Setup & Characterization Weir PW –spatial feature & process window models –Calculate component precision and their contributions to feature distortion. –Remove reticle & average field data enhanced exposure tuning and scan-and-slit performance mapping. –Classic lens aberrations and their influence on feature size. –Classic process windows PLUS Across entire field for any number of variables. –Model Films, BARC, TARC, swing curve etc. behavior –Wafer-edge and field-edge aberrations. –Scan region sensitivity –Dose Uniformity –Derive Reticle sizes from wafer data –Lens and reticle heating during exposure. –Map DoF uniformity –Simulate tool performance “What if” Weir PSFM (Focus) –Map aerial image, focal plane uniformity –Model whole–wafer autofocus stability –Map wafer flatness and derive the influence of substrate films on autofocus sensitivity. –Model lens-slit and reticle-scan static and dynamic performance signatures. –Extract wafer-edge and edge-bead effects. –Calculate classic lens aberrations through their influence on feature focus.

TEA Systems 2006TEA Systems Products 20 BottomCD vs Focus Up + SCAN Down - SCAN Scanner AScanner "B" Isofocal region on Scanner A vs B

TEA Systems 2006TEA Systems Products 21 Photomask Process Control Weir PW –Metrology from any data source or manual entry –Process Windows, Bossung Plots etc. –Model etch uniformity from scatterometry –Model feature profiles and etch depth Correlate to wafer response across the process window –Encapsulate data standard format for the wafer-fabrication engineer Provides a valuable commodity by giving the wafer engineer a reticle signature library entry for: –Reticle design qualification –Reticle use re-validation –Wafer process setup thru reticle signature removal –Tool setup for thermal bake and exposure-tool reticle bending

TEA Systems 2006TEA Systems Products 22 MoSiON Fingerprint MoSiON uniformity across Reticle –1D vector plot (top left) –Contour (top right) –3D Contour bottom left

TEA Systems 2006TEA Systems Products 23 Reticle RET Qualification Qualify Reticle Enhancement Techniques Weir PWWeir PW –Use Focus or Focus-Dose Matrices –Calculate true reticle size Weir automatically removes wafer, film and focus errors as well as dose perturbations Sub-nanometer accuracy from CDsem or Scatterometry Works with all RET methods –Correlate to measured reticle variables Optimize reticle etch depth for RET –Calculate Depth-of-Focus uniformity for each scanner/stepper –Calculate Best Focus for this RET design –Qualify simulator responses –Determine simulator variable values Reticle signature and damaged site

TEA Systems 2006TEA Systems Products 24 CD-SEM Reticle MEF+ = Optimized BCD from Wafer Nanometrics Reticle MEF+ = Calculated & measured Reticle Size

TEA Systems 2006TEA Systems Products 25 Thermal Process setup LithoWorks PEB –Import Thermal probe data from any commercial system –Visualize and model thermal flow, cycles, uniformity. –Calculate energy delivered to segments of the substrate. –Align and correlate thermal energy and model data to spatial models of critical feature elements across the wafer and bake plate. Weir PW –Correlate wafer-spatial model response to thermal response variables LithoWorks PEB Thermal Probe Plot

TEA Systems 2006TEA Systems Products 26 PEB 7; Thermal energy variation Energy variation around the average temperature. Represents the area “under the curve” –Variations below the mean wafer temperature at each slice are considered negative (deg- sec) –Right side of wafer receives less themal energy

TEA Systems 2006TEA Systems Products 27 Thermal range and transitions: PEB 8

TEA Systems 2006TEA Systems Products 28 Bake versus Feature correlations Photoresist Thickness

TEA Systems 2006TEA Systems Products 29 Metrology validation Weir PW –Validate scatterometry model range and repeatability –Calculate metrology tool precision –Determine the limits of metrology tool variation

TEA Systems 2006TEA Systems Products 30 Metrology: Variable Covariance Understanding the covariance of thresholds and measured values is critical. Below is a covariance matrix of multiple features measured in the data set. The plot shows the covariance of two selected variables Graph selections are easily made using the drop-down and check-boxes provided. Top & bottom die sites

TEA Systems 2006TEA Systems Products 31 LER, ARC and Resist evaluation Weir PW –Use with 4-point probe, electrical or scatterometry data –Calculate swing curves from normal product data or focus–dose matrices –LER from any CDsem or other linewidth tool mapped to wafer/field position Calculate covariance with other metrology variables –ARC thickness and Photoresist optimization Bottom or Top ARC’s Determine thickness changes with focus/dose Calculate changes in optimum focus with ARC type and dose Compare to other brands for process window, influence on DoF, optimum focus etc.

TEA Systems 2006TEA Systems Products 32 Process Setup & Control Weir PW –Standard Process Windows Independent / simultaneous rectangular and elliptical windows –Full-field process window models Needed for sub-90 nm nodes Any number of features and field-sites. –Full-field Depth-of-Focus –Removal of wafer tilt and bow prior to modeling –User and automated data culling –Swing curve fitting from production or dose matrix data sets. –Thickness-loss curve fitting –Film uniformity monitors –Visual, whole-wafer and whole field mapping of process window. –Wafer radial and edge-bead analysis. –Exposure tool dose uniformity evaluations. Weir PSFM –Aerial Image, full-field and wafer focus modeling –Flatness & Tilt control Only software capable of calculating wafer tilt –Focus uniformity –Edge influence on auto- leveling and auto-focus –Edge bead analysis

TEA Systems 2006TEA Systems Products 33 Scatterometry Process Window Dose= Focus Process Window Exposures 193nm litho process for 100nm features –AT1100 scanner, 0.75NA with annular illumination –90nm gratings at 1:1 with full field coverage –240nm resist on 78nm Barc on Si OCD metrology: NI, rotating polarized light (Nano9030) diffractive optical metrology (scatterometry) - outputs spectral intensity changes of 0 th order diffracted light intensity ?Weir PW Software from TEA Systems

TEA Systems 2006TEA Systems Products 34 Metrology & Process Independent Characteristics Focus Uniformity Depth of Focus Uniformity

TEA Systems 2006TEA Systems Products 35 Process Window Setup Interface

TEA Systems 2006TEA Systems Products 36 Process Window - center of field

TEA Systems 2006TEA Systems Products 37 Spatial comparison of parameters Examine and compare systematic variations across the wafer Provides information of process sensitivity Systematic errors can be removed from data to enhance analysis resolution. Data shown as 1D vector & contour plot (lower right) SWA PResist thickness CD Threshold ARC Coat SWA v Wafer Radius

TEA Systems 2006TEA Systems Products 38 Best Focus

TEA Systems 2006TEA Systems Products 39 Report Best Focus Portion of a Weir Data Workbook report on BCD vs Dose response when Focus errors are removed

TEA Systems 2006TEA Systems Products 40 Modeled Production Gating Weir PW –Model profile variation across the field and wafer –Pass/fail wafers for redo loops or control based on modeled results Results in fewer wafers rejected when compared to “mean+3 sigma” gating tests –Model film thickness, profiles, Side-wall-angle (SWA), CD size, etc.

TEA Systems 2006TEA Systems Products 41 Simulation validation Weir PW –Evaluate film thickness and feature profiles –Correlate data with outputs from Prolith, Sigma C etc. –Calculate simulator variables to improve simulations –Determine influence of the full process window on simulators

TEA Systems 2006TEA Systems Products 42 Focus optimization Weir PW –Derive focus and dose uniformity from feature focus-matrices and line-end-shortening. –Calculate "Best Focus" across field (IFD) and Focal-plane uniformity from any Critical Feature metrology set, Line-End-Shortening –Determine Dose response from focus-error-free data Weir PSFM –Calibrate Phase Shift Focus Monitor (PSFM), Phase Grating( PGM), End-of-Line, and Z-spin Reticles. –Apply reticle calibrations to whole-wafer focus uniformity analyses. –Calculate both wafer and field tilt, bow and random errors –Calculate the effects of thermal heating during exposure –Effects of film, trench-etch, wafer and and scanner stage –Wafer edge-bead and edge-die influence –Measure wafer flatness. –Analyze ASML FOCAL focus dataASML FOCAL with raw or modeled full-field analyses

TEA Systems 2006TEA Systems Products 43 Focus Slit Profile Focus uniformity across lens (slit) Field-modeled piston and tilt have been removed. PGMPSFM160PSFM180FOCAL

TEA Systems 2006TEA Systems Products 44 X-Slit Astigmatism Artemis (from 3/2002) Annular (0.85/0.55) PGM FOCAL PSFM 180 PSFM 160 Shape of curve for Z5 Artemis coefficient and the Focal Astigmatism plot is good –Field tilt is included in the FOCAL data Magnitude of the plots is off Also recall that the FOCAL data is from a ring-aperture setting.

TEA Systems 2006TEA Systems Products 45 Tool Programmed Offsets “Mean” focus is plotted Tool focus set to –0.1 –Median effective focus = Offsets follow programmed values (above) very closely. –-0.24 field is shown by arrow for orientation Background focus, no offsets

TEA Systems 2006TEA Systems Products 46 Relative Measured Field Offsets Restricted analysis wafer diameter to 85 mm radius Removed mean field Relative offsets of each field is clearer

TEA Systems 2006TEA Systems Products 47 Recommended System Requirements Minimum recommended system: –Windows 2000 or XP Professional –Microsoft Excel version 9 or later –Pentium IV, 1.2 Gigahertz CPU –256 Megabytes of RAM –Monitor 1024x780

TEA Systems 2006TEA Systems Products 48 License Basis License formats –Licenses are software locks that are keyed to the hardware upon which it is installed. –Licenses can be input manually or delivered via text files. –License periods can be set from 1 to 365 days or as a permanent license –Demonstration, lease and permanent licenses are available. Single-user node-locked license –License is locked to a computer’s disk –Only one user, on the target computer may use the license Floating node license –License is locked to a computer’s disk –Any user on the network can access and use the software –Only one user at a time may use the software –Software image shuts-down after 30 minutes of non-use Thereby freeing the license for the next user.

TEA Systems 2006TEA Systems Products 49 Summary of Weir PW Any metrology data can be imported –Weir PW contains a layout optimizer and basic metrology analysis capabilities –Any user-defined variable names may be used –Data is stored in Microsoft Excel® worksheet and workbooks Multiple data sets can be combined and data sub-sets selected for analysis –Point-and-click mouse interaction for data viewing and culling “Metrology” analysis –Automated metrology covariance –Automated error-budget analysis. Spatial analysis of variables –Provides information on variation with scan direction and film thickness variation –Point-and-click drill down capability for sub-field graphics, data viewing and analysis –Remove critical systematic components to see the true exposure performance Process Window analysis and more! –Extend beyond the single feature/family analysis. –Examine process window performance variation across the full field of exposure. Automation –Weir DM can be used to automate process-monitor points for any variable series.

TEA Systems 2006TEA Systems Products 50 Extra Wafer Maps of 6 th order parameter variation (next section) These slides illustrate the variation of measured feature size across the wafer and field. More importantly, they illustrate that feature sizes can be modeled as systematic errors across each. Note that when these systematic errors are removed, the residuals track the variation of underlying film thickness (such as.anti-reflective coatings) and thermal-variation (Post Exposure Bake) across the wafer during processing. Slide 34 is a good example. Weir therefore provides a direct method of measuring both feature and film- variation influence on feature size.

TEA Systems 2006TEA Systems Products 51 PhotoresistPhotoresist All terms4 th & 6 th only Residuals to all terms

TEA Systems 2006TEA Systems Products 52 ARCARC Residuals to Wafer Model Mean Field Removed Wafer ModelResiduals to all Wafer Coefs

TEA Systems 2006TEA Systems Products 53 CD 95% Threshold Wafer model; 4 th & 6 th order only Wafer ModelResiduals to Wafer Model; mean field removed.

TEA Systems 2006TEA Systems Products 54 SWASWA