Weir PSFM Focus uniformity calculations for lens aberrations, stage & scan characterization and reticle-platen tuning Weir PSFM Weir PSFM and the Benchmark PSFM/PSG reticle form a wavefront engineering toolset unique in the industry for critical focal-plane element analysis, Tool control calculation, yield estimation, behavioral visualization and automated modeling for capability optimization. TEA Systems Corp. 65 Schlossburg St. Alburtis, PA

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -2- Weir PSFM/ Highlights Program Weir PSFM/PSG Operation Mode Engineering – analytical tools Manufacturing – Daily Monitor templates Automation – APC model engine Platform Window 2000, XP etc. Data Input Any overlay or registration metrology Automated input. Data Storage Microsoft Excel workbooks. Organization “Open” system with easy access to data and analysis results Applications Metrology verification and setup Reticle verification Exposure tool ?setup and analysis of lens, reticle-platen and wafer chuck ?Lens matching ?uniformity analysis ?Sub-system precision calculation ?focus budget optimization Process ?Optimization ?Error budget analysis ?Yield estimation

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -3- Agenda Weir PSFM Overview Data acquisition & setup The three modes of operation ?PSFM & PGM Reticle Calibration ?Lens aberrations in the “Best Focus” field ?Fixed Focus analysis Wafer and Field Modeling Example: Astigmatism and wafer model Resolution of topographic steps Tool Precision calculation Analysis Automation with Weir DM Summary

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -4- Weir Data Import manual data import ?Data is selected from the Weir Analysis import screen Weir can import Binary, ASCII or Excel data formats ?The data is stored in an Excel spreadsheet. ?Weir uses user-defined variable names from the raw data set. “Test” numbers correlate to information shown on the “Sites” spreadsheet. The information sheet contains additional setup parameters Therma-Wave Optiprobe CD Supports any metrology data including overlay, CD, thickness etc.

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -5- Layout optimizer Provides ?Layout fine tuning for centering and parameter updates. Point-and-click updates of scan, NA, focus, dose coherence etc. ?Basic metrology with statistics and visualization graphics such as histograms, XY- scatter, wafer, field plots, contour and 3D plots ?Exposure tool library maintenance and selection ?Access to Weir focus, process window and daily monitor modules.

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -6- Operational Modes Weir Calibration ?lens aberrations ?calibration templates for reticles ?tuning Weir Software Suite PSFM Reticle Patterns ?Perform isolated –feature based analysis PGM or PSG Patterns ?Analyze performance for dense-packed features Weir Fixed-Focus ?Wafer stage performance ?Slit & scan characterization ?tuning Weir DM ?Calibration, fixed focus & raw data ?Trend charts ?Lot analysis

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -7- Analysis Flow - Reticle Calibration Import and layout data Calibrate the PSFM Reticle Optional: Calculate the “Best Focus” Aerial Image response Save the calibration to a Calibration Template Save the calibration to a Calibration Template Reticle Calibration Reticle Calibration/ Template Generation: Perform one-time for a given Reticle and NA/Sigma Template Library Templates are needed for each unique Reticle, NA & Sigma value used

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -8- Automated calibration of every site 1.Field object shows site layout 2.Calibration can be restricted by layout variable setup. 3.Set automated range & sigma data culling, press calibrate and every site on the reticle is calibrated. 4.Calibrations are displayed and stored in the spreadsheet. 5.Accuracy ( = 193nm) PSFM < 12 nm focus PSFM < 1.5 nm - 3 sigma

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -9- Best Focus – the lens Aerial Image 1.Most accurate calculation of lens aberrations Piston, Tilt, Astigmatism, Curvature 2.Focus budget: Astigmatism: um After tilt & bow are accounted for Tilt;loss of um Curvature:0.017 um -9nm in X, +9 nm in Y Residuals0.143 um Residuals are also contributing to astigmatism. 3.Best Focus Setting The best focus Tool setting is at –0.042 um. “What if” Simulations

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -10- Analysis Flow for Fixed Focus Import and layout data Calibrate the PSFM Reticle Optional: Calculate the “Best Focus” Aerial Image response Save the calibration to a Calibration Template Save the calibration to a Calibration Template Reticle Calibration Reticle Calibration/ Template Generation: Perform one-time for a given Reticle and NA/Sigma Import and layout data Go to Focus uniformity Analysis Window Select the proper Calibration Template Fixed-Focus Analysis Fixed-Focus Analysis: Perform daily or as needed. Select the Conversion Option. “All-Sites” is default. Select the Conversion Option. “All-Sites” is default. Press “(re)Calculate” command button to convert overlay to Focus Optional: select data sub-set of wafer, dose, NA, PC etc values Wafer Graphic will appear to show you the focus data selected Select “Analysis” tab to continue FOCUS analysis Template Library Templates are needed for each unique Reticle, NA & Sigma value used

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -11- Fixed Focus: Wafer & Field Modeling Wier’s Zernike wafer analysis clearly resolves the 10 urad of chuck tilt (shown here as a correction of – 10 urad) and 15 urad of reticle tilt. Modeled results are stored in the excel spreadsheet along with the data (see below).

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -12- Astigmatic variation Top – View of wafer modeled tilt & bow Bottom, view of horizontal focus, systematic errors. Previous Horizontal Feature plot Note baseline focus drift

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -13- Residuals re-plotted Slit & scan by column

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -14- Modeled Residuals plotted by Column plotted by Rows

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -15- Tool Precision budget 1.Click on the Precision tab to calculate the precision dataset. 1.Values are displayed in “one- sigma” variations. 2.Definitions & method of calculated can be viewed by pressing the F1 key or by going into the help menu. 2.Values in the “Scan” (Y) direction varied more than along the slit (X) 3.Wafer-to-wafer or InterWafer variation is small. 4.InterField variation from stage stepping, leveling and focusing is greater than IntraField, or fixed field variation. 5.Overall lot precision is (64.5, 85.9) nm one-sigma. 6.Results are stored on the “Precision” spreadsheet of the workbook.

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -16- Weir DM: Analysis Automation Any analysis sequence can be automated for implementation in the production environment using the Weir Daily Monitor (DM) Weir DM Setup Screen entered through the Weir Engineer “Tools/Daily Monitor Setup” menu item. Statistics displayed will be specified in the second “Graphics Display” tab. Statistics and trend charts maintained are specified in the “Statistics Display” tab. Any analysis sequence can be automated for implementation in the production environment using the Weir Daily Monitor (DM) Weir DM Setup Screen entered through the Weir Engineer “Tools/Daily Monitor Setup” menu item. Statistics displayed will be specified in the second “Graphics Display” tab. Statistics and trend charts maintained are specified in the “Statistics Display” tab. Reticle data or Component (Mean or Best Focus fields) can be removed.

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -17- 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 Corp. Confidential Nov. 2003Weir PSFM OverviewPage -18- Weir DM Trend Charts The Weir DM software plots one template chart for each data variable selected. Above is shown the data for the “Mean - 3sigma statistic”. Corresponding data for the Best Focus, or data mean is shown on the right Here we observe “Mean” feature settings. Vertical (X) and Horizontal (Y) focus data can also be viewed. Measurement date shown on the abscissa.

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -19- Field Focus Field modeled best focus is changing with wafer number (right). If we look at vertical (slit) focus, we can see the focus drift until about the 6 th wafer. Horizontal (scan) focus remains constant. This is consistent with lens heating effects. Lens (slit) focus Scan focus Average

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -20- Astigmatism Astigmatism, also sensitive to lens heating, is shown to settle after the 8 th wafer.

TEA Systems Corp. Confidential Nov. 2003Weir PSFM OverviewPage -21- Summary of Weir PSFM Any metrology data can be imported ?Weir PW contains a layout optimizer and basic metrology analysis capabilities ?Data is stored in Microsoft Excel® worksheet and workbooks Layout of Dose, Focus, NA, PC and stage/scan direction ?Supported by graphic tools as well as simple point-and-click entry. Modes of operation ?Calibration PSFM/PGM reticle template generation “Best Focus” lens aberration analysis ?Fixed-Focus Stage and wafer-edge performance Average or selected field analysis. User can remove mean-field, best-focus or selected modeled aberrations prior to performing analysis. Modeled wafer and field ?Weir DM Automation of frequently performed Calibration, Fixed-Focus or Raw Data. Automation ?Weir DM can be used to automate process-monitor points for any variable series.