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Diamond disks are indispensable for dressing CMP pads. However, due to the leveling requirement, only a few percents of diamond grits can penetrate the pad. As these few crystals are worn out, the plastic deformation of the pad becomes large relative to the amount of pad is cut. Consequently, the pad becomes highly deformed and loaded with dirt. The polishing rate will then decline; and the scratch rate, increase. A novel technique has been developed to identify the cutting tips and their dulling process. The cutting paths become widen and shallow with more and more deformed pad material. Eventually, fewer and fewer scratch lines are present with most touching diamond pushing deformed pad around. Because there are only a handful of diamond grits that are engaged in cutting pad, the number of working crystals can increased substantially by improving the leveling of diamond tips. This improvement can increase the longevity of diamond disks that paves the way for future CMP of 18 inches wafers scheduled to make the debut in 2012.

A mosaic design of diamond disks that incorporates different cutting characteristics of diamond grits can allow faster polishing of wafers with less pad consumption. Larger diamond grits can make pad asperities with large peak to valley ratios for achieving high polishing rate. On the other hand, Sharp grits can shave the pad effectively as to eliminate the glazed layer. The conventional diamond disks employ similar type of diamond grits across the entire disk. These grits cannot dress and cut the pad with optimization. By combining different types of diamond grits in a cocktail combination, the pad asperities can be controlled to enhance removal rates of the wafer. The glazed layer may also be removed cleaner so wafer defectivity is minimized.

Diamond disks are indispensable for dressing CMP pads in the manufacture of semiconductors. Conventional diamond disks contain one type of diamond grits, with the aim to achieve two different functions, viz. glaze shaving and asperities grooving. Cocktail diamond disks are made by assembling brazed diamond pallets that contain different types of diamond crystals. Thus, the pad can be dressed clean, and at the same time, asperities may polish wafers fast without damaging.

Due to the continual improvement of CMP technologies, and the need for polishing delicate wafers at high speed, graphite impregnated pads (GiP) dressed by brazed organic dia mond disks (BODD) can double the throughput of wafer-pass at the reduced cost of ownership (CoO). The increased polishing rate is due to the act of nano graphite particles that absorb slurry. The nano graphite particles coated with chemical and abrasive can achieve high removal rate without causing scratches on the wafer. In addition, nano graphite particles do not stick to wafer surfaces, so they can be cleaned easily. BODD can uniquely dress GiP to create slurry channels so the pore free pad is not bottlenecked by slurry supply. This paper also demonstrated the low stress polishing by applying ultrasound during the CMP process.

All conventional pad conditioners dress the CMP pad with discrete diamond grits of random orientation. With the advent of polycrystalline diamond (PCD) dressers, the pad conditioning can be performed with an unprecedented regularity. The result is a total elimination of "killer asperities" that may scratch the soft copper layer or porous dielectric layer. Moreover, the PCD dressers may be constructed to form a blade shaver so pad disruption during conditioning can be minimized. As a result, the original pad polymers can be preserved for polishing wafers. This ultimate diamond disk (UDD) has transformed stick slipping pad destruction to smooth shaving pad construction. UDD is particularly suitable for dressing CMP pads for polishing 22 nm interconnects, in particularly, with the anticipated debut of 450 mm pancake wafers scheduled for 2012.

All pad conditioners used for CMP today are made by attaching discrete diamond grits on a flat substrate. Polycrystalline diamond (PCD) was wire-EDM cut to form blades with different designs of cutting tips. These blades were assembled to form the so-called ultimate diamond disk (UDD). The pad asperities formed with UDD were compared with conventional diamond disks. It was confirmed that UDD dressed pad asperities were more uniform than that for polishing IC wafers today. The UDD dressed pads were also used to polish tungsten (W) IC layer deposited on 300 mm wafers. As the surface of PCD contains only merged diamond grains that are corrosion immune, UDD was dressing in-situ, by immersing in the acid slurry. The wafer uniformity so polished was comparable to that of ex-situ CMP pad dressing with metallized diamond disks. The in-situ dressing can boost the CMP throughput by deglazing the pad in real time while the wafer is being polished. After 15 hours, the wafer profiles for this in-situ dressing were sustained without decay.

Instead of attaching individual diamond grits to a metal substrate, Advanced Diamond Disk (ADD) are manufactured by Electro Discharge Machining (EDM) of sintered Polycrystalline Diamond (PCD) to form cutting pyramids of a designed shape. This is not possible with single crystal diamond grits that possess obtuse solid angles for dressing plastic pads. The test data confirmed that ADD can dress pad more effectively than conventional pad conditioners with discrete diamond grits. Moreover, the service lives of ADD and pad can both be lengthened due to the much milder dressing action. These unique features of ADD can reduce significantly the Cost of Consumable (CoC) of Chemical Mechanical Planarisation (CMP) for the manufacture of advanced semiconductors.