• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.854-857
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• 2000

Chemical Mechanical Polishing(CMP) has been accepted as one of the essential processes for VLSI fabrication. However, as the polishing process continues, pad pores get to be glazed by polishing residues, which hinder the supply of new slurry. This defect makes removal rate decrease with a number of polished wafer and the desired within-chip planarity, within wafer and wafer-to-wafer nonuniformity are unable to be achieved. So, pad conditioning is essential to overcome this defect. The eletroplated diamond grit disk is used as the conventional conditioner, And alumina long fiber, the .jet power of high pressure deionized water and vacuum compression are under investigation. But, these methods have the defects like scratches on wafer surface by out of diamond grits, subsidences of pad pores by over-conditioning, and the limits of conditioning effect. To improve these conditioning methods. this paper presents the Characteristics of Ultrasonic conditioning aided by cavitation.

• Journal of the Semiconductor & Display Technology
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• v.3 no.1
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• pp.15-20
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• 2004

Through shallow trench isolation (STI) chemical mechanical polishing (CMP) tests, we investigated the dependence of pad surface temperature on the abrasive and additive concentrations in ceria slurry under varying pressure using blanket film wafers. The pad surface temperature after CMP increased with the abrasive concentration and decreased with the additive concentration in slurries for the constant down pressure. A possible mechanism is that the additive adsorbed on the film surfaces during polishing decreases the friction coefficient, hence the pad surface temperature gets lower with increasing the additive concentration. This difference in temperature was more remarkable for the higher concentration of abrasives. In addition, in-situ measurement of spindle motor was carried out during oxide and nitride polishing. The averaged motor current for oxide film was higher than that for nitride film, meaning the higher friction coefficient.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.886-891
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• 2018

Colloid silica using as abrasive for polishing sapphire has been extensively studied, which mechanism has also been deeply discussed. However, by the requirement of application enlargement and cost reduction, some new problems appear such as silica service life time, particle diameter mixing, etc. In this paper, several influences of colloid silica usage on sapphire CMP are examined. Results show particle diameter and concentration, pH value, service life time, particle diameter mixing heavily influence removal rate. Further analysis discloses there are two main effect aspects which are quantity of hydroxyl group, contact area for abrasive density stacking between abrasive and sapphire. Based on the discussions, a dynamic process of sapphire polishing is proposed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.211-213
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• 1999

In this paper, we documented the controlling oxide removal amount on the pattern wafer using removal rate and removal thickness of blanket wafer. There was the strong correlation relationship for both(correlation factor:0.7109). So, we could confirm the repeatability as applying for STI CMP process from the obtained linear formular. As the result of repeatability test, the difference of calculated polishing time and actual polishing time was 3.48 seconds based on total 50 lots. If this time is converted into the thickness, it is from 104$\AA$ to 167$\AA$. It is possible to be ignored because it is under the process margin.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.12a
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• pp.122-125
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• 2003

We investigated the effect of the abrasive and additive concentrations in Nano ceria slurry on the pad surface temperature under varying pressure through chemical mechanical polishing (CMP) test using blanket wafers. The pad surface temperature after CMP increased with the abrasive concentration and decreased with increase of the additive concentration in slurries for the constant down pressure. A possible mechanism is that the additive adsorbed on the film surface during polishing decreases the friction coefficient, hence the pad surface temperature gets lower with increase of the additive concentration. This difference of temperature was more remarkable for the higher concentration of abrasives. In addition, in-situ measurement of spindle motor was carried out during oxide and nitride polishing. The averaged motor current for oxide film was higher than that for nitride film, which means the higher friction coefficient.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.193-194
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• 2005

By the high-temperature pad conditioning process: The slurry residues in pores and grooves of the polishing pad were clearly removed. These clear pores and enlarged grooves made the slurry attack the oxide surface. The changed slurry properties by high-temperature pad conditioning process made the oxide surface hydro-carbonate to be removed easily.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.5
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• pp.976-985
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• 2002

The purpose of this paper is that the roughness(Rrms = 31$\AA$, Rp-v = 270$\AA$) of ITO thin film deposited by sputtering method for OELD is improved to Rrms $\leq$ 10$\AA$, Rp-v $\leq$ 80$\AA$ by chemical mechanical polishing(CMP). First, ITO thin films are polished with a variety of consumables (Pads, Slurries) to choose proper some for the roughness improvement and the CMP mechanism of ITO thin films is demonstrated on the ground of the experiment results. Henceforth, the CMP characteristics (Removal rate, Non-uniformity) of chosen consumables are evaluated according to processing conditions (Polishing pressures, Table velocities) and suitable conditions for ITO film CMP are selected. Finally, the electrical and optical properties (Sheet resistance, Transmittance) of ITO thin films are investigated to verify whether or not ITO thin film are still suitable for OELD after polished.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.235-239
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• 2001

In recent years, as Chemical Mechanical Planarization(CMP) has been routinely utilized in integrated circuit(IC) fabrication, the consumption of slurry, main consumable in a CMP process, is greatly increased. Thus the reprocess of CMP slurries has been actively considered in the industry to reduce cost-of-consumable (COC). The main purpose of this study was to recycle the used oxide slurry using filters as a new method. As a result, Ultra Fine(UF) Filter could distinguish silica from the used oxide slurry and Reverse Osmosis(RO) Filter could distinguish Deionized(DI) Water and chemistry from chemistry solution. The tetraethylorthosilicate removal rate was almost the same as the number of recycle polishing was increased, when it was modified by slightly adding new SS-12 slurry. The microscratch didnt found as the number of recycle polishing was increased.

• Transactions on Electrical and Electronic Materials
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• v.7 no.3
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• pp.108-111
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• 2006

The oxidizer-induced corrosion state and microstructure of surface passive metal-oxide layer greatly influenced on the removal rate of tungsten film according to the slurry chemical composition of different mixed oxidizers. In this paper, the actual polishing mechanism and pH-potential equilibrium diagram obtained from potentiodynamic polarization curve were electrochemically compared. An electrochemical corrosion effect implies that slurries with the highest removal rate (RR) have the high dissolution rate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.4
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• pp.309-313
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• 2006

Pad surface characteristics such as roughness, groove and wear rate of pad have a effect on the within wafer non-uniformity(WIWNU) in chemical mechanical polishing(CMP). Although WIWNU increases as the uniformity of roughness(Rpk: Reduced peak height) becomes worse in an early stage of polishing time, WIWNU decreases as non-uniformity of the Rpk value. Also, WIWNU decreases with the reduction of the pad stiffness, though original mechanical properties of pad are unchanged by the grooving process. In addition, conditioning process causes the inequality of pad wear during in CMP. The profile of pad wear generated by the conditioning process has a significant effect on the WIWNU. These experiments results could help to understand the effect of pad surface characteristics in CMP.