CMP consumable: Pad Classes of Pad

Class I. Felts and polymer impregnated Classes of Pads Class I. Felts and polymer impregnated Representative; PellonTM, SubaTM Class II. Microporous synthetic leathers Representative; PolitexTM Class III. Filled polymer films Representative; IC1000 Class IV. Unfilled textured polymer films Representative; OXP3000

Slurry loading capacity ;Medium Typical applications PellonTM, SubaTM Felts and polymer impregnated ;continuous channels between fibers Slurry loading capacity ;Medium Typical applications ; Si stock polish, Tungsten CMP Surface Cross section

PolitexTM , SurfinTM , UR100TM Microporous synthetic leathers ; Vertically oriented, open pores Slurry loading capacity ; High Typical applications ; Si final polish, Tungsten CMP, Post CMP buff

Microporous polymer sheet Slurry loading capacity ; Low IC1000TM , IC1400TM Microporous polymer sheet ;Closed cell foam Slurry loading capacity ; Low Typical application ;Si stock, ILD CMP, STI metal damascene CMP Surface Cross section

Non-porous polymer sheet with surface macrotexture OPX3000TM, IC2000TM Non-porous polymer sheet with surface macrotexture Slurry loading capacity ; Minimal Typical application ;ILD CMP, STI CMP, metal dual damascene Cross section

Control of pad properties through pad geometry Pad thickness Groove Designs Base Pads

Pad thickness Polishing pads used for CMP are typically about 1.3mm -> 2.0 mm Above about 5mm, polishing uniformity may suffer because of the inability of the pad to comform to variations in global wafer flatness Stiffness is less dependent on the grooved thickness, which is removed during pad use. Unfilled pads will planarize more effectively than filled pads

Pad thickness

Groove design To prevent hydroplaning of the wafer being polished across the surface of the polishing pad. To ensure that slurry is uniformly distributed across the pad surface and that sufficient slurry reaches the interior of the wafer. To control both the overall and localized stiffness of the polishing pad. To act as channels for the removal of polishing debris from the pad surface.

Base Pad Best planarity is achieved with no base pad. However, polishing uniformity across the wafer is poor caused by imperfect wafer flatness and thickness Using a base pad compromises planarity but improve uniformity across the wafer by reducing the impact of the other problems. Other problems are so-called “edge effect”

Base Pad

Type 1 Type 2 Type 3 Type 4 Structure Felted fibers impregnated with polymeric binder Porous film coated on a supporting substrate Microporous polymer sheet Non-porous polymer sheet with surface macrotexture Microstructure Continuous channels between fibers Vertically oriented, open pores Closed cell foam None Slurry loading capacity Medium High Low Minimal Pad examples PellonTM, SubaTM PolitexTM, SurfinTM, UR100TM, WWP300TM IC1000TM, IC1010TM, IC1400TM, FX9TM, MHTM OXP3000TM, IC2000TM Compressibility Very Low Stiffness Very High Hardness Typical applications Si stock polish, Tungsten CMP Si final polish, Tungsten CMP, post-CMP buff Si stock, ILD CMP, STI, Metal damascene CMP ILD CMP, STI, Metal dual damascene

Fixed abrassive pad - Reduction of Dishing & Erosion (Source: ROHM Co.) - Achievement in Removal Rate comparing with Conventional CMP Dishing in case of conventional pad Dishing in case of fixed abrasive pad

Manufacturing of Fixed abrassive pad Abrasive Mixer of Binders Printer Side View of Pad Fixed Abrasive Pad Pattern UV Curing Printing of Binder

Viscoelastic Measured pad properties Viscoelastic behavior of each pad Pad’s behavior measuring equipments & program Instantaneous deformation characteristics of pads (1st modulus of pad – E1) - IC 1000TM > IC 1400TM > SUBA 800TM > SUBA 400TM • Time dependent creep characteristics of pads (2nd modulus of pad – E2) - IC 1400TM > IC 1000TM > SUBA 800TM > SUBA 400TM Viscoelastic behavior of each pad Measured pad properties