Study on the Development of Resource-Saving High Performance Slurry - Polishing/CMP for Glass Substrates in a Radical Polishing Environment, Using Manganese Oxide Slurry as an Alternative for Ceria Slurry

Abstract

While investigating polishing mechanism of glass substrates with ceria abrasives (CeO2), we found its oxidizing properties worked effectively for the polishing. This finding has inspired us to speculate about the possibility of the manganese oxide abrasives as an alternative for ceria as they also have oxidizing properties. Therefore, focusing on the valence of the manganese, we have experimentally manufactured MnO, MnO2, Mn2O3 and Mn3O4 abrasives, and conducted a comparison study of the characteristics obtained with ceria slurry and manganese oxide slurries. As a result, the surface roughness of below Ra 0.8nm obtained with Mn2O3 slurry was found better than that with the conventional ceria slurry, on top of which, its removal rate was as good as or equal to that of ceria. Using a novel, closed type CMP (Chemical Mechanical Polishing) machine, we conducted another glass polishing experiment with ceria and manganese oxide slurries. The inside of the CMP machine was filled with high-pressure gases such as oxygen, air and nitrogen and kept at 500kPa to make the polishing environment radical. Through this experiment, we found an effective polishing method for high-quality surface. The removal rates were several times better than that of the conventional polishing performed in an open CMP machine.

Effects of Changes in Gas Type and Partial Pressure on Chemical Mechanical Polishing Property of Si Substrate

“…It needs to be noted that in 500kPa air atmosphere, as N 2 existing in the air bears most partial pressure, thus the solubility of O 2 in the slurry is affected and the material removal rate in such atmosphere is lower than that in pure O 2 high-pressure atmosphere. 17,[23][24][25] Through analysis of the experimental results mentioned above, it can be concluded that the Si substrate material removal rate of CMP can be increased by changing the processing atmosphere (gas pressure and gas componenents) and the main influential factor is the increase of O 2 partial pressure, which can cause the concentration of DO in the slurry to increase. and high-pressure O 2 atmosphere respectively for 24-hour dissolution test.…”

“…Therefore, to design and develop CMP techniques that are suitable for these new materials has become a focus of the researchers, and outstanding achievements have been made through extensive researches. For example, Professor Doi et al used high-speed equipment in conjunction with high-pressure device to polish power semiconductor materials at high speed in order to increase the processing efficiency mechanically, the material removal rate was improved significantly and high-quality z E-mail: yintaoyy120@gmail.com surface was obtained; 13,14 Professor Babu and Yin et al employed the chemical efficiency-increasing method, in which strong oxidant was added to corrode the copper substrate and the silicon carbide substrate, and the processing quality and efficiency were improved significantly; [15][16][17][18][19][20] Professor Lee used multicrystalline diamond slurry to process the sapphire substrate, and the material removal rate was improved significantly while ensuring the processing quality. 21,22 However, for those methods mentioned above, almost all CMP processes were carried out in open environments and the impact of processing environments on the entire CMP process was neglected.…”

Mn2O3 Slurry Achieving Reduction of Slurry Waste

“…As manganese oxide has been revealed to have some interesting characteristics, several corresponding studies have been performed. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Some of these studies reported that manganese oxide slurry polishes several materials such as tungsten, copper, SiO 2 , and low dielectric constant materials.…”

Effect of Mn-Based Slurries on Chemical Mechanical Polishing of SiC Substrates

“…10,11 DOI and SESHIMO developed a CMP/plasmachemical vaporization machining (CMP/P-CVM) method that significantly increased the removal efficiency and surface quality of SiC substrates. 12,13 Wang et al used femtosecond-laser-irradiationassisted CMP to improve material removal by destabilizing surface crystals. 14 Yuan et al used UV-TiO 2 -photocatalysis-assisted CMP to increase the material removal rate and surface quality of 4H-SiC wafers.…”