The effect of slurries on lapping performance of fixed abrasive pad for Si₃N₄ ceramics

Abstract

In this paper, a series of experiments were carried out to explore the effect of slurry pH on materials removal rate (MRR) and surface quality in lapping of Si3N4 ceramics wafers with fixed abrasive pad (FAP) using different slurries with different pH. Then, the scanning electron microscope was employed to detect the microtopography and abrade smooth of FAP for exploring the effect of slurries pH on self-conditioning of pad. Experimental results demonstrated that the roughness of wafers increase with the increasing of slurry pH value. The surface of wafers is the best when the pH = 1 and the worst When the pH = 13. The MRR decreases firstly and then decreases with the increasing of the pH. The MRR reaches the lowest when slurry pH = 7, and reaches the highest when slurry pH = 13. These results further suggest that the soften layer of SiO2 could be formed due to the reactions between water and materials on wafer surface, which facilitates increasing material remove rate and improving the surface quality. The hydrogen ion and triethanolamine in slurry could react with the copper in fixed abrasive pad, which also could enhance the materials remove rate and affect the surface quality.

Tribological glazing evolution of fixed abrasive pad under different polishing solution conditions

“…A research conclusion was proposed that the self-dressing performance of the pad had limited effect on its surface-glazed phenomena which was also occurred after a longer using time. Wang et al (2020aWang et al ( , 2020b researched the surface characteristics of FAP with selfconditioning ability using Si 3 N 4 ceramic sheet polishing experiment under different solution pH values condition. The experimental results showed that a certain degree of wear and glazed phenomenon on the FAP surface was also existed in the CMP process.…”

“…Lee et al (2017) investigated the effect of self-dressing property of fixed abrasive pad with sapphire substrate on its glazed phenomenon. A research conclusion was proposed that the self-dressing performance of the pad had limited effect on its surface-glazed phenomena which was also occurred after a longer using time Wang et al (2020a, 2020b…”

“…The above-mentioned conclusions have indicated that the surface-glazed phenomenon of polishing pad is existed in CMP process, which has important effect on the CMP performance. Thus, the diamond conditioners (Zhou et al, 2008;Wang et al, 2020aWang et al, , 2020b, high pressure micro jet (Tsai and Yang, 2012;Kim et al, 2005) and other technologies (Shin et al, 2016) were proposed for solving this problem of polishing pad. The experimental results have showed that these technologies can remove the glazed layer on the pad surface, which improves the material removal ability of the polishing pad.…”