Hyun-joon Kim

Multi-Sensor Monitoring System in Chemical Mechanical Planarization (CMP) for Correlations with Process Issues

In this paper, three different sensors were used to measure multi-scale phenomena in chemical mechanical planarization. A piezoelectric force sensor, Hall effect sensor and acoustic emission sensor (AE) were installed in CMP equipment and the signals were measured simultaneously during the polishing process. The results showed that the sensors measuring frictional behaviour, such as the Hall effect sensor and force transducer, produced a clear end point signal in the case of the friction characteristics are distinguishable for each material. Also, if there is difference in hardness between materials, then a sharp end point signal is detected with the AE sensor even though the friction characteristic is similar between the two materials. Therefore, using multi-sensors having different bandwidths is complementary for not only process monitoring but also end point detection.

Synthesis and characterization of Group 4 metallocene complexes with two disiloxanediyl bridges

Group 4 metallocene complexes with two disiloxanediyl bridges [μ,μ-(Me 2 SiOSiMe 2 ) 2 (C 5 H 3 ) 2 ]ZrCl 2 ( 3 ) and [μ,μ-(Me 2 SiOSiMe 2 ) 2 (C 5 H 3 ) 2 ]HfCl 2 ( 4 ) have been prepared by the reaction of MCl 4 (M=Zr, Hf) with distannylated bis(cyclopentadienes), while the zirconium complex, 3 , was subjected to a single-crystal X-ray diffraction study. The reaction of TiCl 4 with two equivalents of doubly disiloxane bridged distannylated bis(cyclopentadienes) gives rise to the formation of the doubly bridged dinuclear titanocene [μ,μ-(Me 2 SiOSiMe 2 ) 2 (C 5 H 3 ) 2 ][TiCl 3 ] 2 ( 5 ) . Methylation and benzylation of the complex 3 results in [μ,μ-(Me 2 SiOSiMe 2 ) 2 (C 5 H 3 ) 2 ]ZrMe 2 ( 6 ) and [μ,μ-(Me 2 SiOSiMe 2 ) 2 (C 5 H 3 ) 2 ]-Zr(CH 2 C 6 H 5 ) 2 ( 7 ), respectively, without complications. Furthermore, the dibridged zirconium compound 3 polymerizes ethylene very efficiently in the presence of methylaluminoxane with an activity of 5 ton of PE/[Zr] mol h atm.

Copolymerization of styrene and ethylene with mononuclear and dinuclear half-titanocenes

With mononuclear half-titanocenes such as CpTiCl3, IndTiCl3, and Me5CpTiCl3, as well as the constrained geometry catalyst (CGC) and a new dinuclear hexamethyltrisiloxanediylbis(cyclopentadienyltitanium trichloride) (TSDT), the copolymerization of styrene and ethylene was examined. The thermal properties and structure of copolymerization products were investigated with differential scanning calorimetry and 13C-nuclear magnetic resonance. In addition, the raw polymer was separated into homopolymer and copolymer with an extraction method and cross fractionation chromatography. With the above analysis, it was concluded that the raw polymer obtained with CpTiCl3 and IndTiCl3 was a mixture of syndiotactic polystyrene and polyethylene homopolymers with 10–30 wt % copolymer, whereas that produced by Me5CpTiCl3 and TSDT was a homopolymer mixture with a negligible amount of copolymer. Only CGC produced the copolymer of styrene and ethylene perfectly.

Organic carrier supported metallocene catalyst for olefin polymerization

The organic carrier supported metallocene catalyst of the present invention is prepared by preparing a ligand complex of a silicone compound having at least one halogen, an alkyl group and a cycloalkane dienyl group, activating styrene polymer or styrene/divinylbenzene copolymer with a strong base including a metal atom such as Li, Na, K or Mg, reacting the activated polymer or copolymer with the ligand complex of a silicone compound so that the ligand may be supported on the activated polymer or copolymer, and reacting the organic carrier supported ligand with a compound of a transition metal of Group IVb of the Periodic Table or Lanthanides of Atomic Number 58-71. The styrene polymer or styrene/divinylbenzene copolymer may be alkylated by Friedel-Crafts alkylation before they are activated with a strong base.

Improvement of LDI BUMP Stripping Process by Development of Room Temperature PR Stripper

Bump process using gold bump led to many cleaning problems like polymer residues, metal and polyimide consumption after stripping process. First of all, stripping process of bump photoresist is one of the difficult technologies since thickness of PR pattern of bump is thicker than that of general metal line at least 100 times. We investigated the improvement of LDI BUMP stripping Process at 25 with new chemical. We found that the wettability may be improved when the additive was added to the chemical and it improves the stripping ability. It was found that new chemical was superior to commercial chemical in terms of chemical stability, removal efficiency of polymer residue and decrease in metal and polyimide consumption. Also, we could obtain removal mechanism of photoresist pattern by measured Raman equipment and enhancement of yield in mass production line of semiconductor.

Development of a 3D Motion Sensor Module

This paper presents a development of a 3D motion sensor IC which detects inertial movements and earths magnetic fields for a compass heading. It consists of a 3-axis accelerometer, a 2-axis geomagnetic sensor, and a microcontroller. An automatic calibration and measurement system is developed to reduce test lead time. For the geomagnetic sensor part, an accuracy of plusmn5 degrees, a resolution of plusmn1 degrees, and a linearity of plusmn1% in full scale range have been achieved. The accelerometer has a full measurement range of plusmn2g. Both sensitivity of 819 count/g with a 12-bit analog-to-digital converter and a linearity of plusmn0.5% in full scale have been achieved. While driving voltage can operate between 2.7 and 3.3 V, current consumption is 3.2 mA at 2.8 V. Thorough reliability test is performed and the sigma level of geomagnetic sensor heading accuracy is 5.6, and that of accelerometer sensitivities are 4.6, 5.6, and 4.5 for x, y, and z axis respectively. The dimension of a packaged chip is 8.3 mm X 5.3 mm X 1.5 mm.