Chemical-Mechanical Polishing of Low Dielectric Constant Polymers and Organosilicate Glasses: Fundamental Mechanisms and Application to IC Interconnec

ISBN-13: 9781461354246 / Angielski / Miękka / 2014 / 229 str.

Christopher Lyle Borst; William N. Gill; Ronald J. Gutmann

Opis

As semiconductor manufacturers implement copper conductors in advanced interconnect schemes, research and development efforts shift toward the selection of an insulator that can take maximum advantage of the lower power and faster signal propagation allowed by copper interconnects. One of the main challenges to integrating a low-dielectric constant (low-kappa) insulator as a replacement for silicon dioxide is the behavior of such materials during the chemical-mechanical planarization (CMP) process used in Damascene patterning. Low-kappa dielectrics tend to be softer and less chemically reactive than silicon dioxide, providing significant challenges to successful removal and planarization of such materials. The focus of this book is to merge the complex CMP models and mechanisms that have evolved in the past decade with recent experimental results with copper and low-kappa CMP to develop a comprehensive mechanism for low- and high-removal-rate processes. The result is a more in-depth look into the fundamental reaction kinetics that alter, selectively consume, and ultimately planarize a multi-material structure during Damascene patterning.

Spis treści

Preface. Acknowledgements. 1: Overview of IC Interconnects. 1.1. Silicon IC BEOL Technology Trends. 1.2. SIA Roadmap Interconnect Projections. 1.3. Low-kappa Requirements and Materials. 1.4. Need for Low-kappa CMP Process Understanding. 1.5. Summary. 1.6. References. 2: Low-kappa Interlevel Dielectrics. 2.1. Fluorinated Glasses. 2.2. Silsesquioxanes. 2.3. Organosilicate Glasses. 2.4. Polymers. 2.5. Fluorinated Hydrocarbons. 2.6. Nanoporous Silica Films. 2.7. Other Porous Materials. 2.8. References. 3: Chemical-Mechanical Planarization (CMP). 3.1. CMP Process Description. 3.2. CMP Processes with Copper Metallization. 3.3. CMP of Low-kappa Materials. 3.4. CMP Process Models. 3.5. Langmuir-Hinshelwood Surface Kinetics in CMP Modeling. 3.6. References. 4: CMP of BCB and SiLK Polymers. 4.1. Removal Rate in Copper Slurries. 4.2. Surface Roughness. 4.3. Surface and Bulk Film Chemistry. 4.4. Effect of Cure Conditions on BCB And SiLK Removal. 4.5. Effect of CMP and BCB and SiLK Film Hardness. 4.6. Comparison of BCB and SiLK CMP with Other Polymer CMP. 4.7. Summary. 4.8. References. 5: CMP of Organosilicate Glasses. 5.1. Surface Roughness. 5.3. Surface and Bulk Film Chemistry. 5.4. Copper Damascene Patterning with OSG Dielectrics. 5.5. Summary. 5.6. References. 6: Low-kappa CMP Model Based on Surface Kinetics. 6.1. Isolation of the Chemical Effects in SiLK CMP. 6.2. CMP with Simplified 'Model' SiLK Slurries. 6.3. Phenomenological Model for CMP Removal. 6.4. Five Step Removal Model Using Modified Langmuir-Hinshelwood Kinetics for SiLK CMP. 6.5. Two Step Removal Model Using Heterogeneous Catalysis for SiLK CMP. 6.6. Extendibility of Model to Describe the CMP of Other Materials. 6.7. References. 7: Copper CMP Model Based Upon Fluid Mechanics and Surface Kinetics. 7.1. Flow Model. 7.2. Copper Removal Model. 7.3. Model Results. 7.4. Copper CMP Experiments with Potassium Dichromate Based Slurry. 7.5. Summary. 7.6. References. 8: Future Directions in IC Interconnects and Related Low-&kgr; ILD Planarization Issues. 8.1. Planarization of Interconnects with Ultra Low-&kgr; ILDs. 8.2. Alternatives for the Post-Copper/Ultra Low-&kgr; Interconnect Era. 8.3. 3D Wafer-Scale Integration using Dielectric Bonding Glues and Inter-Wafer Interconnection with Copper Damascene Patterning. 8.4. Summary and Conclusions. 8.5. References. Appendices: A: Experimental Procedures and Techniques. B: XPS Depth-Profile Data. C: CMP Data for Anomalous SiLK Removal Behavior. Index.