Effects of slurry filter size on the chemical mechanical polishing (CMP) defect density

Generation of Pad Debris during Oxide CMP Process and Its Role in Scratch Formation

“…However, most of the particles were detected in the range of 0.2-0.3 lm, and some of the large particles were detected in the range of 20-300 lm. 1,7,15,[23][24][25]27 At this condition, there may be a permanent flattering of the pad asperities, and also the reduction of surface roughness would occur. Figures 3a-3c show the SEM images of pad debris at magnifications of  300,  500, and  20,000, respectively.…”

“…Figure 13 shows the number of scratches formed on the oxide wafer after each CMP process. 7,9,10,23 It should be noted that the pad debris generated during the process would also play a critical role in the scratch formation, and it is necessary to understand the mechanism of scratch formation caused by the pad debris. It could be concluded that the pad debris generated during the CMP process plays a key role in forming the scratches.…”

“…[4][5][6][7] One of the major concerns during this process is defect formation. 7 Possible sources in generating these scratches are agglomerated particles, pad debris, and hard defects coming from the wafer bulk. These consequences can severely affect the manufacturing process of semiconductor chips.…”

Retreatment of silicon slurry by membrane processes

“…The adjustment with the concentrated slurry is made in the mixing tank and the amount is determined by the ratio of dissolved chemical compounds described in Section 2.1. A step of post filtration at 1 m (12) is performed to remove any residue that may damage the wafers [16,17]. Then the re-treated slurry can supply CMP polisher through a pressurized loop with continuous recirculation and extraction towards the polisher identical to the industrial ones.…”

Effects of conditioning temperature on polishing pad for oxide chemical mechanical polishing process

“…CMP performances can be optimized by several process parameters such as equipment variables (table and head speed, down force, and slurry flow rate) and consumables (pad, backing film and slurry) [6][7][8][9]. Among the consumables for CMP process, especially, pad and slurry play very important roles in the removal rates and within-wafer nonuniformity (WIWNU%) for global planarization ability of CMP process [10].…”