Chap 11 Chemical mechanical planarization1 18 Chemical Mechanical

Chap 11. Chemical mechanical planarization(1)

18. Chemical Mechanical Planarization

18. Chemical Mechanical Planarization etchback reflow Spin-on CMP

18. Chemical Mechanical Planarization WIWNU WTWNU Oxide CMP RTA Metal CMP Slurry

18. Chemical Mechanical Planarization Porous PU EPD Post CMP Cleaning

18. Chemical Mechanical Planarization STI LI ILD Tungsten Copper

Chemical Mechanical Planarization Introduction • What is CMP? • Necessity of CMP • Applications of CMP Equipment Configuration Consumables • Slurries • Pads • Brushes and Conditioner Process Issues • Removal rate • Selectivity • Dishing and Erosion Post CMP Cleaning Summary

Introduction What is CMP is mechanically enhanced chemical etching or chemically enhanced mechanical grinding CMP is able to planarize surfaces by removal of material such that topography is eliminated or material is left at defined areas CMP provides local and global planarity CMP enables indirect patterning due to an adjustable polish selectivity between different materials Necessity of CMP Photolithography resolution R = k 1 / NA To improve resolution, NA or DOF = �k 2 /(NA)2, both approaches to improve resolution reduce DOF Planarization is inevitable for lithography for the 0. 25 µm node and below Applications of CMP STI formation Tungsten plug formation Deep trench capacitor Cu dual damascene

Via Contact source: chihiwu@cc. ee. ntu. edu. tw

Equipment configuration Polishing Head Slurry Dispenser Pressure Membrane Wafer Retaining Ring Polishing Pad Platen Slurry

Pad and conditioner Slurry Dispenser Polishing Head Polishing Pad Conditioner

472 tool

Polishing head Vacuum Chuck Downforce Pressure Retaining Ring Positioning Carrier Chamber Retaining Ring Membrane Wafer Uniformity Control