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I NV E N TIV E CONFIDENTIAL Is Co-existence Possible? David White Virtual Manufacturing Use Model Prediction Step Calibration Step Fabricate Test Wafer (ECP/CMP) Test Wafer Design Layout File Data from ECD & CMP Processing Measurement Results ECD/CMP Virtual Mfg Process Library Data From Test Wafer Geometry Extraction Calibrate Model Product Design Layout File Geometry Extraction Predict New Design Full-Chip Prediction Semi-Physical Model Tailored to Specific Process 2 July 18, 2015 ECD/CMP Virtual Mfg Process Library Cadence Confidential: Cadence Internal Use Only Tailored to Customer’s Process & Design Topographical Analysis What Are Pattern-Process Interactions Structures with Same Line widths, Same Local Density, and Same Polish Conditions Have Very Different Cu Loss Memory Analog IP Blocks Rotated IP Block High CPU Block Thickness Low IITC 2005, Nagaraj NS: “Copper and Low k Scaling Challenges: A Design Perspective” 3 July 18, 2015 Cadence Confidential: Cadence Internal Use Only Accounting For Variation in Design Process Actual Thickness +20% Systematic & Random Thickness Manufacturing Variation Guardband Systematic Thickness Manufacturing Variation Guardband -20% Current “2D” Methodology is Conservative Full Chip Guardband for Both Systematic and Random Thickness Variation (+- 20%) +10% Actual Thickness -10% Random Thickness Manufacturing Variation Guardband Cadence “3D” Methodology Eliminates Systematic Guardband Leaving Only a Relatively Small Random Thickness Variation (+- 10%) 4 July 18, 2015 Cadence Confidential: Cadence Internal Use Only Experimental Results: CMP Aware Routing Normalized Variation CMP variation 1 0.98 0.96 0.94 0.92 0.9 0.88 0.86 0.84 • On average 7.5% reduction • Up to 10.1% reduction ibm01 ibm03 ibm05 BoxRouter ibm07 ibm09 Wire density Normalized timing Timing 1 0.98 0.96 0.94 0.92 0.9 0.88 0.86 0.84 • On average 7% reduction • Up to 10% reduction ibm01 ibm03 BoxRouter 5 July 18, 2015 ibm05 ibm07 Wire density Cadence Confidential: Cadence Internal Use Only ibm09 [Cho et al, ICCAD’06] Rules versus Models as Function of Pattern-Process Dependent Interaction MORE (Volumes) Non-linear, multi-dimensional process or system HIGH Complexity LESS LOW LOCAL 6 July 18, 2015 Value of Models Value of Rules Complexity Process Interaction Cadence Confidential: Cadence Internal Use Only GLOBAL Deficiencies with Pure Rules Based Approach Results in Loss of Accuracy Characterization of Pattern-Process Behavior Pattern Geometries Design Rules Little Value Back to Manufacturing Manufacturing Customer Capturing all meaningful interactions into rules Violations & Scoring Metrics Local versus global interactions Design Customer 7 July 18, 2015 Cadence Confidential: Cadence Internal Use Only Design Tools Deficiencies with Pure Model Based Approach Significant Value Back to Manufacturing Characterization of Pattern-Process Behavior Speed? Pattern Geometries Process Models Manufacturing Customer Volumes of Data (width and thickness dimensions) No Filtering of Data Design Tools e.g. 25M thickness values Why does speed have question mark? To be addressed later Results in Speed and Data Issues 8 July 18, 2015 Cadence Confidential: Cadence Internal Use Only Design Customer What to do with Data? How does it impact my design? Rules and Models Not Mutually Exclusive Significant Value Back to Manufacturing Characterization of Pattern-Process Behavior Manufacturing Customer Global Pattern Geometries Speed Volumes of Data Process Models Local Pattern Geometries Accuracy (width and thickness dimensions) Design Rules Violations & Scoring Metrics Design Customer 9 July 18, 2015 Cadence Confidential: Cadence Internal Use Only Design Tools 65nm Rule Deck Example • Ran three separate 65nm rule decks on 65nm production design • 96% of operation counts are done with 0 halo size • Density rules using 100 micron window size are less than 1% of overall operations but 5% of overall execution time 100% 90% 80% 100% 70% 90% 60% 50% 80% % Operation Counts 70% % Execution Time 40% 60% 30% 50% 20% 40% % Operation C % Execution Ti 30% 10% 20% 0% Halo Size 10 July 18, 2015 Cadence Confidential: Cadence Internal Use Only dw sz 3 28 28 113 .3 .2 1 56 41.5 .6 1 69 .8 84 .9 198 .1 11 2 3. 26 2 .4 14 25 1. 4.7 5 28 16 3 9. d 8 w sz 19 8. 1 22 6. 4 25 4. 7 0 84.9 .6 0% 56 .3 28 0 10% Backup / Q&A 11 July 18, 2015 Cadence Confidential: Cadence Internal Use Only Models Complement Rules Design Rules Say OK, Models Say Its Not Acceptable Metal 4 Copper Density Metal 4 Copper Loss 0.70 1200A 0.70 2500A • • Both Areas Have 70% Average Density But Very Different Copper Loss 1200A 12 July 18, 2015 Cadence Confidential: Cadence Internal Use Only 2500A Process for Forming Interconnect (Wires) Features Defined Through Lithography and Etch dielectric copper ECD Copper Plating Step 1: Copper Plating dielectric Copper CMP (Bulk) Step 2: Bulk Polish Copper CMP (Touchdown) Step 3: Copper Clear or Touchdown Copper CMP (Barrier) Step 4: Barrier Removal 13 July 18, 2015 Cadence Confidential: Cadence Internal Use Only Rules versus Models as Function of Uncertainty in Process Characterization MORE (Volumes) Non-linear, multi-dimensional process or system HIGH Value of Models Value of Rules LESS LOW POORLY CHARACTERIZED UNSTABLE PROCESS 14 July 18, 2015 Process Maturity Cadence Confidential: Cadence Internal Use Only WELL CHARACTERIZED STABLE PROCESS Chemical Mechanical Polishing Force Modern polishing heads have separate rings where the force can be radially adjusted Table with Pad Rotating Within-Chip Variation: dominated by layout, pad and slurry interaction Within-Wafer Variation: dominated by pressure zone apportionment in carrier and relative velocities of carrier and table 15 July 18, 2015 Cadence Confidential: Cadence Internal Use Only Interconnect Variation Wafer Level Variation • • • Within-Chip Variation is Huge! – Thickness Variation: 10% to 30% – Width Variation: 10% to 30% Due to Design Impact on Manufacturing – Varying Feature Density – Varying Feature Widths Variation Leads to Over-Compensation in Design – Timing Failures – Decreased Performance – Increased Power Consumption Within-Chip Variation Oxide Loss Dishing Isolated Isolated Thin-Lines Wide-Lines 16 July 18, 2015 Total Copper Loss Dense Array Thin-Lines Dense Array Wide-Lines Cadence Confidential: Cadence Internal Use Only Wafer Surface Chip Surface 17 July 18, 2015 Cadence Confidential: Cadence Internal Use Only