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FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 1 Collaborative Platform, Tool-Kit, and Physical Models for DfM FLCC Pre-Presentation Feb 12th, SPIE March 1, 2007 Andy Neureuther, Wojtek Poppe, Juliet Holwill, Eric Chin, Lynn Wang, Jae-Seok Yang, Marshal Miller, Dan Ceperley, Chris Clifford Jihong Choi, Dave Dornfeld UC Berkeley, Koji Kikuchi, Sony Visiting Industrial Fellow John Hoang, Jane Chang U.C. Los Angeles Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 2 Need for Design for Manufacturability (DfM): Parametric Yield Loss Increasing to 25% Yield σ: ±5% Yield σ: +5% to -50% Random 100 90 Process-Related Systematic Reticle-Related (RET impact) 80 Nominal Yields (%) Systematic 70 60 50 Leakage Power, Delay & Cross-Talk Design-Related (leakage, performance, power) 40 30 20 10 0 0.35µm 0.25µm 0.18µm 0.13µm Feature Dimension 90nm Source: IBS Discussion courtesy of Nickhil Jakatdar Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN DfM Requirements: Context-based, Adaptive Model Resolution In the Design Increased model resolution for optimizing critical and sensitive paths In the Flow Adaptive model resolution and speed-accuracy tradeoff to match abstraction level RTL Synthesis Prototyping Physical Synthesis Nets/Paths Routing Regions Optimization Sign-off Slide courtesy of Nickhil Jakatdar, Cadence Copyright 2007, Regents of University of California Model Resolution 3 FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 4 Technology Advances to Integrate into DfM Slide courtesy Martin van den Brink, Photomask 06 Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 5 Opportunities in DfM Platforms Broad Reach to encompass all contributions to complexity New Collaborations (Process, Device, Design) supporting viewpoint of each with the intuitive terminology of each New Functionalities for Visualization and Assessment Physical Models Very Fast and first-cut accurate Complete set of processes: to Integrate Complexity Litho, CMP, Etch, Device, Metrology Complete set of interactions between processes: Litho-CMP Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 6 Key Leverage Point for DfM: Express nonidealities at the mask plane /NA) /NA) Defocus Spherical Mask phases • yellow = 0° • green = 90° • red = 180° HO Spherical /NA) Coma /NA) /NA) HO Coma Move nonidealities to the mask plane for visualization and quantification early in Design Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 7 Lithography Network: Tools and Concepts defocus Aberration Monitors TEMPEST •90° •0° •180° •270° Pattern Matching Pattern (coma) IFT Mask Layout Collaborative Platform for DFM Pattern Matcher Aerial Image Simulator Module 1 Processing BSIM model SPLAT Match Location(s) Module 3 Circuit Standardized BSIM Model Output Copyright 2007, Regents of University of California Module 2 Device FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 8 Feature Level Compensation and Control: Industry and UC Discovery Collaboration SVTC Copyright 2007, Regents of University of California 17 Supporters 2 Contributors 3 Former FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 9 FLCC: Modeling and Characterization Litho Etch Metrology and Control oxide poly-Si CMP oxide Device Collaborative Experiments Toppan & Photronics Cypress & ASML AMD CMP Drain 1 Cypress Cypress Poly Cypress Poly Block Fab. Wafer Block ON Metrology Contact Metal Active Center Poly DuPont Cypress DDLI DDLI Cypress Block Mask Block Drain 2 ON ON ON Quasar OPC Poly Annular OPC Poly Corner Poly ON Source 1 Copyright 2007, Regents of University of California Source 2 FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 10 Process Aware EDA Toolkit Lateral Image Effects Robustness Metrics Tool Kit Interactions & Placement Crosstalk Interconnect Delay Move polygon with mouse Easy to find optimal solution Module 1 Processing BSIM model Module 3 Circuit Standardized BSIM Model Output Module 2 Device Original proximity effect As polygon moves, hotspots disappear and appear Collaborative Platform for DfM Drag-and-Drop Hot Spot Fixer Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 11 Collaborative Platform for DfM:Concept Wojtek Poppe Parametric Yield Simulator Transistor Modeling Simulation Process Simulation Collaborative Platform for DFM Experiment Circuit Simulation 65nm Testchips SolutionsCopyright across2007, disciplines rather than within disciplines Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 12 Collaborative Platform for DfM: Implementation Module 1 Processing Viewpoint Rosetta Stone BSIM model Module 3 Circuit Standardized BSIM Model Input Module 2 Device Intuitive Parameters Circuit Simulation across characterized process window Copyright 2007, Regents of University of California Non-rectangular transistors FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 13 Collaborative Platform for DfM: Implementation SPLAT Module 1 Processing Viewpoint BSIM Rosetta Stone BSIM model Module 3 Circuit Standardized BSIM Model Input HSPICE Module 2 Device Intuitive Parameters Circuit Simulation across characterized process window Copyright 2007, Regents of University of California Non-rectangular transistors FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 14 Collaborative Platform for DfM: Use Circuits Design Evaluation Implementation on Design Side Processing Incremental Improvements Module 1 Processing BSIM model Module 3 Circuit Standardized BSIM Model Output Module 2 Device CAD Create robustness metrics for process aware timing and power analysis Copyright 2007, Regents of University of California Device Use standard BSIM model Modeling non-rectangular transistors FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 15 Collaborative Platform for DfM: Validation Six contributors from five research areas FLCC Enhanced Transistor Electrical CD Metrology Made possible Feature Level Compensation Copyright 2007, Regentsby of University of California and Control (FLCC) FLCC Pre-Presentation of SPIE DFM-PI 07 ARN Process Aware EDA Toolkit Wojtek Poppe Lynn Wang Eric Chin Juliet Holwill Jae-Seok Yang Robustness Interconnect Lateral Image Metric Delay Interactions & Placement Crosstalk • quantifying the circuit performance robustness of layout snippits with an indexing metric • control of leakage through maximizing optical image quality of drivers/buffers, • mitigating optical spillover effects and optimizing robustness metrics in placement, • visualizing chip level effects on delay variation, and • checking robustness closure through estimating variations in interconnect. Copyright 2007, Regents of University of California 16 FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 17 Drag-and-Drop Hot Spot Fixer Move polygon with mouse Easy to find optimal solution Original proximity effect As polygon moves, hotspots disappear and appear • • • Problem hotspot identified in layout on left. Drag and Drop Hotspot Fixer on right shows how a designer can drag a polygon with a mouse and have real-time hotspot re-evaluation as the polygon moves. Hotspot severity is color coded, green means hotspot free. Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 18 Visualization of Focus Effects at Layout Juliet Holwill Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 19 Image Behavior with Focus and Coma Intensity Vs Distance at a range of coma levels for 0.193 NA = 0.5, defocus = 0.01 Intensity Vs Distance at a range of coma levels for 0.193 NA = 0.5, defocus = -0.01 0.9 Intensity versus Distance for a range of focus values with Lambda = 0.193 NA = 0.5 0.8 0.7 1.6 0.6 Intensity 1.4 1.4 1.2 0.5 0.4 0.3 1.2 0.2 1 0.1 -0.04 Defocus 1 -0.04 coma 0 0 Defocus 0.02 Defocus 0.6 0.04 Defocus Intensity Intensity 1 -0.02 Defocus 0.8 1.05 1.1 1.15 1.2 1.25 Distance (um ) 1.3 -0.02 Coma 0 Coma 0.8 0.02 Coma 0.04 Coma 0.6 0.4 0.4 0.2 0.2 0 0 0 0.5 1 1.5 2 2.5 3 3.5 0 0.5 1 2 2.5 3 3.5 Distance (um) Distance Cutline 1.5 The intensity change with focus generally increases regardless of the sign, whereas the intensity of coma changes sign with the sign of coma. Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN Pattern Matching Accuracy: Line End Shortening (LES) 20 Line End Shortening 0.06 I L dL dI LES Line End Shortening (um) 0.05 0.04 Coma 0.03 0.02 0.01 0 -0.05 -0.04 -0.03 -0.02 -0.01 0 0.01 0.02 0.03 0.04 0.05 0.04 0.05 Coma Amount (waves RMS) Aberration Level Line End Shortening 0.085 Defocus LES LES can be modeled using the product of the match factor times the aberration level. For Coma, LES is linear For Defocus, LES is parabolic Line edge shortening (um) 0.08 0.075 0.07 0.065 0.06 0.055 0.05 0.045 Juliet Make 0.04 LES = Line End Shortening -0.05 -0.04 -0.03 -0.02 -0.01 0 0.01 0.02 Defocus Amount (waves RMS) Aberration Level Copyright 2007, Regents of University of California 0.03 FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 21 Phase-Shifting Mask Spillover Trends Mask Type Slope Coma MF ΔL Splat ΔL PM Focus (0.02 Coma) MF (0.02 Coma) ΔL Splat (0.04 Focus) Binary 6.95 0.075 4nm 0.309 38nm Att. PSM 0.094 2nm 0.318 27nm 7.933 Alt. 9.083 0.150 18nm 0.342 30nm PSM The Pattern Match Factors and spillover light increases with the additional light Cutline through the mask but the impact on edge placement is partially mitigated by the increase in image slope. Copyright 2007, Regents of University of California ΔL PM (0.04 Focus) FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 22 Off-Axis Illumination Trends: Mutual Coherence Mask Functions Tophat Illumination Quadrupole Illumination Annular Illumination Dipole Illumination Mutual coherence functions taken from “Resolution Enhancement Techniques in Optical Lithography”, Alfred Wong. Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 23 Polarization Trends Radial periodic grating focuses high-NA effects into center Ez(center) = (- j 2 Ex NA) 2 cos() 0 = Ez(null, L=S) 2 sin() (unpolarized light) Intensity (CF) Maximum signal at = 90 1.0 0.66 0.33 0.4 0.6 Copyright 2007, Regents of University of California 0.8 Make Andy NA 1 FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 24 Assessment of Gate Layout Effects: Approach The pattern matcher is a fast tool for searching layouts for locations with the highest similarity to a given image. The input patterns are chosen to be the most sensitive to a particular aberration or illumination error. The snippets from these locations can then be simulated, rather than the whole layout The match factor is a measure of similarity of a layout geometry to a pattern at a particular location It is calculated as the 2D discrete Juliet Make convolution Copyright 2007, Regents of University California Range = of[-1,+1] FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 25 Assessment of Gate Layout Effects: Results Match Factor Vs Intensity Change with Coma MF I 2 Intensity Change 0.15 The match factors returned for a given layout may be used to predict the expected intensity change in the presence of coma -0.05 -0.10 Match Factor 0.25 The match factors returned for a given layout may be used to predict the expected intensity change in the presence of coma Changing pitch and additional ‘kickers’ give this layout snippet a high match factor Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 26 DRC Compatible Monitors and Calibration Many modifications are possible, and each will be tested for sensitivity. These are some examples of constructed patterns that might be produced. Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 27 Going where “Design Rules Do Not Reach” Coma proximity effect • Function is about 5 feature sizes in diameter and easily reaches across cell or compaction boundaries. • By computing influence functions for diffraction limited proximity Z1, Defocus Z4 and Coma Z7 it is possible to quickly assess image changes through the process window and along a scanner slit. Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 28 Standard Cell Interactions: Approach Boundary Lynn Wang Adjacent cells increase Match Factors and hence variation through focus MF = 0.3 Cell i Copyright 2007, Regents of University of California Cell j FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 29 Standard Cell Interactions: Accuracy Delta L delta L vs. PMF 90 nm Defocus -0.3 -0.2 0.03 0.025 0.02 0.015 0.01 0.005 0 -0.1 -0.005 0 -0.01 -0.015 0.1 R2 = 0.7131 0.2 PMF Copyright 2007, Regents of University of California 0.3 0.4 FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 30 Standard Cell Interactions: Results Cell Interaction Chracterization 90 nm Library: Metal Layer 1 Defocus Cell 1 Cell 3 Cell 2 Cell 3 Cell 3 Cell 3 Cell 1 Cell 2 Cell 2 Cell 2 Cell 3 Cell 2 Cell 1 Cell 1 Cell 2 Cell 1 Cell 3 Cell 1 0.3 0.28 0.24 0.22 0.2 0.18 0 1 2 3 4 5 6 7 8 9 10 Cell Distance Characterization 90 nm: Metal Layer 1 Defocus Cell # 0.35 0.3 Greatest Range= 0.1 Smallest Range= 0.01 0.25 PMF PMF 0.26 0.2 0.15 0.1 0.05 0 0 0.2 0.4 0.6 Distance (um) Copyright 2007, Regents of University of California 0.8 1 1.2 FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 31 CMP Variation Assessment: Physical Model STI process simulation: HDPCVD and CMP HDPCVD Jihong Choi Dave Dornfeld Characterization: Cell 1 Cell 2 HDPCVD CMP Cell 3 Topography map z z2 z1 CMP α ( x, y ) d z pad z3 Pad Asperity z ( x, y ) Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 32 CMP Variation Assessment: Chip Model Chip Layout Pattern density Line width Line space HDP-CVD Deposition Model CMP Input Thickness CMP model Evolution Copyright 2007, Regents of University of California Nitride thinning FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 33 Etch Variation Assessment: Physical Model UCLA Jane Chang John Hoang High density plasma, with O2 in Cl2 Low DC ratio High DC ratio 161 264 275 164 86.9º 136 189 70.5º 247 208 82.5º 293 137 226 85.6º 270 130 72.9º 74.1º 164 High density plasma, O2 in Cl2, low DC ratio Low substrate High substrate bias bias 89 363 161 264 300 86.9º 136 189 33.7º 181 69.8º 247 195 250 82.5º 293 87.7º 320 130 74.1º 71.4º 137 Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 34 Etch Variation Assessment: Layout Chip Field Layout Etcher Iouter Iinner Ws Coil Power Ws Cl2 N2 O2 Pressure Substrate Bias Couple W feature-profile simulations with tool-scale models and plasma ion energy models (Graves and Lieberman at UCB) Identify factors in profile model that have feature level and pattern density dependencies Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 35 Interconnect Variation Assessment: Concept Major Physical Contributors to Variation: - Lithography (Focus, Overlay, Aberrations, …) - CMP (Density, …) - Etch (Sidewall Angle, …) Delay Variation = f(local layout, layout in layers above and below, die location, wafer position) Key idea: Predict interconnect delay variations by tracing Pattern Matches through circuits and adjusting extracted RCs. Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 36 Interconnect Variation Assessment: System Pattern Matcher Parasitic Extraction Predict Geometrical Variations Netlist Backannotation Estimate Changes in R, C Timing Analysis Copyright 2007, Regents of University of California Fast-CAD Techniques: 1) Focus solely on critical paths to improve runtime 2) Pre-characterize libraries to model geometrical variations for different match factors. FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 37 Interconnect Variation Assessment: Result Structure: Array Above Ground Plane Resistance Calculation: L R WH eff 3 cm 110nm 110nm M1 175nm Capacitance Extraction: 450nm ILD0 κ=3.4 Synopsys Raphael: 2D Field Solver C total Cbottomgp 2Ccoupling Nominal CMP Erosion Linewidth (nm) 110 98 122 110 98 122 Values from ITRS 90nm Technology Node GP Delay of a 1mm M1 interconnect (array) Pitch=220nm Space (nm) Height (nm) Ct (fF/mm) R (Ohm/mm) Delay (ps) Error 110 175 180.724 1558.44 97.17 0.00% 122 175 166.61 1749.27 100.55 3.48% 98 175 197.65 1405.15 95.82 -1.39% 110 158 171.39 1726.12 102.06 5.04% 122 158 158.185 1937.48 105.74 8.82% 98 158 187.181 1556.34 100.50 3.43% Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 38 Cross-Talks Variation Assessment: Concept Particle AGGRESSOR AGGRESSOR VICTIM VICTIM AGGRESSOR AGGRESSOR < Designed Layout > Jae-Seok Yang Driver variation - Non-linear rectangle poly(Litho) - Spatial correlation (Drivers are close) Focus correlation Interconnect variation -Width/Spacing(Litho, Etch) -Height(CMP) CD(Victim Driver) distance Dose correlation - CD(poly) + CD(Poly) Target window 1 Crosstalk verification over the process window focus 1 focus Correlation factor(β) Correlation factor (α) < Manufactured Layout > - CD + CD Target window CD(Aggressor Driver) is bound dose distance Copyright 2007, Regents of University of California dose FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 39 Cross-Talk Variation Assessment: Result 65nm Vdd=1.2V Peak Noise over the process windows (mV) AGGRESSOR 100nm VICTIM AGGRESSOR Defocus: -40nm Defocus: 0nm Defocus: 40nm Defocus: 100nm Dose: 10% 243.1 237.2 238.3 234.9 Dose: 0% 242.3 237.5 234.4 231.2 Dose: -10% 234.8 233.5 232.7 230.8 100um 5.3% noise variation over the process window Proposed flow for variation aware SI verification Layout (Full-chip) OPC / Arerial image sim. RC extraction Xtalk analysis critical condidate nets in terms of Xtalk noise Real critical nets for DOF/dose margin Repeat for the next ED condition P&R Arerial image sim. ( poly ) ED constraints considering spatial correlation for poly layer Arerial image sim. ( metal ) ED constraints for metal RC extraction Xtalk analysis Failure criterion No Failure Save as a critical net Yes Copyright 2007, Regents of University of California Repeat for the next critical condidate nets FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 40 Photomask Edge Effect: Physics & Impact Form of Cherenkov radiation =193nm Ey (TE) n=1 Difference field = actual – vertical propagation field Air 39.7o n=1.563 Front Glass Intensity imbalance IEDM 1992 Alfred Wong Cherenkov radiation SPIE 2001 Costas Adam Domain decomposition (edge sources) SPIE 2002 Costas Adam PSM only 180 degrees for one pitch BACUS 2006 Gleason Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 41 Photomask Edge Effect: Characterization Real Imy CER CEI Marshal Miller Sqrt(I2) 0.01 Koji Kikuchi Dan Ceperle y Imy Both Real and Imy Edge Effects Real Duty Cycle 50% Plot Sqrt(I) vs Duty Cycle Adjusting Phase Etch Depth adds Purple to cancel Yellow Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 42 Photomask Edge Effect: Characterization Sqrt(I2) 0.01 Imy 50% Real 3 5 5 5 deg 10 Copyright 2007, Regents of University of California Duty Cycle FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 43 CEI CER Photomask Edge Effect: Characterization TM Cross Talk TE Period in Plot CER and CER vs mask period Large periods give edge parameters Small periods show cross-talk effects Copyright 2007, Regents of University of California Period in FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 44 EUV Defect/Mask Interactions: Modeling Absorber Pattern Specifications Incident Wave Absorber Layout Simulator Defect and Multilayer Specifications FT{ Near Field Multilayer Simulator } Plane Wave Near Field FT{ Near Field } Absorber Layout Simulator Final Result RADICAL: Rapid Absorber Defect Interaction Computations for Advanced Lithography Mask with Buried Defect Refractive Indices of Simulation Domain Resulting Image Plot of AerialAerial Image for NA: 0.45 0.7 1 0 Chris Clifford Defect No Defect 0.99 50 0.6 0.98 100 Defect 0.5 0.97 Y-Axis (nm) 0.96 200 0.95 250 0.94 Intensity (E2) 150 0.4 0.3 300 0.93 350 0.2 0.92 0.1 400 0.91 450 0 50 100 150 200 250 300 X-axis (nm) 350 400 450 500 0.9 0 160 180 Copyright 2007, Regents of University of California 200 220 Distance (nm) 240 260 280 FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 45 EUV Defect/Mask Interactions: Assessment Defect Projector for DFM Characterize buried defect and mask pattern separately Use fast methods to determine: Effect of defect for various layouts Layout mask blank interactions Characterize Defect Defect Library Ray Tracing Multilayer Simulator Possible Layouts and Defect Locations Fast Interaction Simulator Based on RADICAL Copyright 2007, Regents of University of California Severity of Pattern Variation FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 46 RTL Synthesis Prototyping Physical Synthesis Nets/Paths Routing Model Resolution Conclusion: Nature of DfM Optimization Regions Sign-off DfM requires complexity management (beyond human comprehension) new modes and multiple viewpoints for collaboration to integrate process, device and circuit very fast first-cut accurate models complete scope across processes and their interactions circuit performance assessment (power, delay, cross-talk) Designers add complexity management skills to process and device understanding and should be invited to collaborate. Thanks to DARPA, SRC, Industry and U.C. Discovery Copyright 2007, Regents of University of California FLCC Pre-Presentation of SPIE DFM-PI 07 ARN 47 Conclusion: Strategies & Prototypes Module 1 Processing BSIM model Module 3 Circuit Standardized BSIM Model Output Module 2 Device Many nonidealities of manufacturing can be moved to the mask plane and visualized/quantified early. Pattern Matching and Perturbation Modeling have both exceptional speed and adequate accuracy Prototype DfM tools and methodologies were shown for Parametric Yield Simulation process/device/circuits, Visualization/quantification at the mask level Thanks to DARPA, SRC, Industry and U.C. Discovery Copyright 2007, Regents of University of California