• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2007.06a
• /
• pp.667-668
• /
• 2007

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1999.05a
• /
• pp.29-29
• /
• 1999

• Proceedings of the Korean Vacuum Society Conference
• /
• 2004.02a
• /
• pp.109-109
• /
• 2004

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2009.06a
• /
• pp.95-96
• /
• 2009

• Proceedings of the KIEE Conference
• /
• 2006.10a
• /
• pp.101-102
• /
• 2006

PZT thin films, which are the representative ferroelectric materials in ferroelectric random access memory (FRAM), have some serious problem such as the imprint, retention and fatigue which ferroelectric properties are degraded by repetitive polarization. BL T thin film capacitors were fabricated by plasma etching, however, the plasma etching of BLT thin film was known to be very difficult. In our previous study, the ferroelectric materials such as PZT and BLT were patterned by chemical mechanical polishing (CMP) using damascene process to top electrode/ferroelectric material/bottom electrode. It is also possible to pattern the BLT thin film capacitors by CMP, however, the CMP damage was not considered in the experiments. The properties of BLT thin films were changed by the change of polishing pressure although the removal rate was directly proportional to the polishing pressure in CMP process.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.10 no.4
• /
• pp.309-317
• /
• 2000

Langasite is a promising new piezoelectric material for SAW filter application. Little was known until recently about the methods needed to mechanically polish and chemically polish/etch this material. In this experiment, polishing, slurry chemistry and chemical wet etching for langasite is described. Conventional quartz and LN ($LiNbO_3$) polishing methods did not produce satisfactory polished surfaces, and polishing with a colloidal silica slurries has shown to be most effective. The optimum condition was investigated by changing the slurry chemistry. As the planarization effect is very important in SAW filter applications, the examination of the effective particle number effect and the particle size effect was carried out. Z-cut langasite surface which had been polished with the colloidal silica slurries was etched in a variety of etchants. Conventional quartz etchants destroyed the polished surface. Other etchants formed a thin film on the surfaces. In this experiment, the reaction between langasite and a few etching solution was analysed. And an appropriate selective etchant solution for analyzing the defects was synthesized.

• Transactions on Electrical and Electronic Materials
• /
• v.12 no.2
• /
• pp.56-59
• /
• 2011

The characterization of the chemical mechanical polishing (CMP) process for undensified phophosilicate glass (PSG) film is reported using design of experiments (DOE). DOE has been used by experimenters to understand the relationship between the input variables and responses of interest in a simple and efficient way, and it typically is beneficial for determining the appropriatesize of experiments with multiple process variables and making statistical inferences for the responses of interest. The equipment controllable parameters used to operate the machine consist of the down force of the wafer carrier, pressure on the back side wafer, table and spindle speeds (SS), slurry flow (SF) rate, pad condition, etc. None of these are independent ofeach other and, thus, the interaction between the parameters also needs to be understoodfor improved process characterization in CMP. In this study, we selected the five controllable equipment parameters the most recommendedby process engineers, viz. the down force (DF), back pressure (BP), table speed (TS), SS, and SF, for the characterization of the CMP process with respect to the material removal rate and film uniformity in percentage terms. The polished material is undensified PSG which is widely used for the plananization of multi-layered metal interconnects. By statistical modeling and the analysis of the metrology data acquired from a series of $2^{5-1}$ fractional factorial designs with two center points, we showed that the DF, BP and TS have the greatest effect on both the removal rate and film uniformity, as expected. It is revealed that the film uniformity of the polished PSG film contains two and three-way interactions. Therefore, one can easily infer that process control based on a better understanding of the process is the key to success in current semiconductor manufacturing, in which the size of the wafer is approaching 300 mm and is scheduled to continuously increase up to 450 mm in or slightly after 2012.

• Transactions on Electrical and Electronic Materials
• /
• v.12 no.3
• /
• pp.115-118
• /
• 2011

Process characterization of the chemical mechanical polishing (CMP) process for undensified phosphosilicate glass (PSG) film is reported using design of experiments (DOE). DOE has been addressed to experimenters to understand the relationship between input variables and responses of interest in a simple and efficient way. It is typically beneficial for determining the adequate size of experiments with multiple process variables and making statistical inferences for the responses of interests. Equipment controllable parameters to operate the machine include the down force (DF) of the wafer carrier, pressure on the backside of the wafer, table and spindle speed (SS), slurry flow rate, and pad condition. None of them is independent; thus, the interaction between parameters also needs to be indicated to improve process characterization in CMP. In this paper, we have selected the five controllable equipment parameters, such as DF, back pressure (BP), table speed (TS), SS, and slurry flow (SF), most process engineers recommend to characterize the CMP process with respect to material removal rate (RR) and film uniformity as a percentage. The polished material is undensified PSG. PSG is widely used for the plananization in multi-layered metal interconnects. We identify the main effect of DF, BP, and TS on both RR and film uniformity, as expected, by the statistical modeling and analysis on the metrology data acquired from a series of $2^{5-1}$ fractional factorial design with two center points. This revealed the film uniformity of the polished PSG film contains two and three-way interactions. Therefore, one can easily infer that the process control based on better understanding of the process is the key to success in semiconductor manufacturing, typically when the wafer size reaches 300 mm and is continuously scheduled to expand up to 450 mm in or little after 2012.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.65-65
• /
• 2007

Microstructure and surface roughness of the sensing materials should be improved to use them in advanced sensor applications because the uneven surface roughness degrades the light reflection, pattern resolution, and devices performance. Chemical mechanical polishing (CMP) processing was selected for improving the surface roughness of $CeO_2$ which is one of the well known materials for the oxygen gas sensors. Surface roughness and removal rate of spin coated $CeO_2$ thin films were examined with a change of CMP process parameters such as down force and table speed. The optimized process condition, reflected by the surface roughness with the hillock-free surface as well as the excellent removal rate with the good uniformity, was obtained. The effects of the improved surface roughness on the sensing property of $CeO_2$ thin films were also confirmed. The improved sensitivity of $CeO_2$ thin films for oxygen sensors were obtained after CMP process by the improved surface characteristics. Therefore, we conclude that sensing property of $CeO_2$ thin film is strongly dependent on the surface roughness of $CeO_2$ thin films by using CMP process.

• Journal of the Korean Society of Safety
• /
• v.23 no.5
• /
• pp.43-48
• /
• 2008

The magnetic polishing is the useful method to finish some machinery fabrications by using magnetic power. This method is one of the precision polishing techniques and has an aim for clean technology in the transportation of the pure gas in the clean pipes. The magnetic abrasive polishing method is not so common in the field of machine that it is not known to widely. There are only few researchers in this field because of non-effectiveness of magnetic abrasive. Therefore, in this paper deals with development of the magnetic abrasive using Ba-Ferrite. In this development, abrasive grain GC and CBN has been made by using the resin bond fabricated at low temperature. And magnetic abrasive powder was fabricated from the Ba-Ferrite which was crushed into 200 mesh. The XRD analysis result shows that only GC, CBN and Ba-Ferrite crystal peaks were detected, explaining that resin bond was not any more to contribute chemical reaction. From SEM analysis, we found that GC, CBN abrasive and Ba-Ferrite were strongly bonding with each other.