1. CMP consumable: Pad
Classes of Pad

2. 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

3. 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

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

5. 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

6. 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

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

8. 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

9. Pad thickness

10. 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.

11. 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”

12. Base Pad

13. 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

14. 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

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

16. 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