Papers by Author: Hyun Seop Lee

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Authors: Yong Chang Guo, Young Kyun Lee, Hyun Seop Lee, Hae Do Jeong
Abstract: Groove pads are used quite widely in chemical mechanical polishing (CMP), and groove size plays an important role in CMP characteristics. This study focuses on the investigation of the groove size effect using X-Y groove pads which are different with pitch and width. The first experiment shows the size effect on the polishing characteristics including material removal rate (MRR), within wafer non-uniformity (WIWNU) on 4 inch oxide blanket wafers for 60 seconds. The second experiment verifies the reason why MRR and WIWNU are different, by the calculation of slurry duration time (SDT) resulting from the change of friction force. All experimental results indicated that a significant difference of slurry flow attributed to groove width and pitch has an impressive influence on friction force, finally the MRR and WIWNU are affected by the groove size.
Authors: Hyun Seop Lee, Boum Young Park, Sung Min Park, Hyoung Jae Kim, Hae Do Jeong
Abstract: Chemical mechanical polishing (CMP) has become the preferred technology to achieve global planarization of wafer surfaces. Especially in oxide CMP, mechanical factors have a greater effect on the removal rate than chemical factors. So, the effects of mechanical parameters in CMP can be expressed as friction force and heat caused by friction. The friction force can be evaluated by a CMP friction force monitoring system and process temperature can be obtained by an infrared rays (IR) sensor. Furthermore, friction energy can be calculated from the friction force monitoring system. In this paper, research on the correlation between frictional and thermal characteristics of SiO2 slurry and CMP results was conducted. This data, which was obtained by using integrated monitoring system for CMP, will lead to the efficient prediction of CMP results.
Authors: Ho Jun Lee, Boum Young Park, Hyun Seop Lee, Suk Hoon Jeong, Heon Deok Seo, Suk Bae Joo, Hae Do Jeong, Hyoung Jae Kim
Abstract: Silicon carbide (SiC) is a wide band gap semiconductor being developed for high temperature, high power, and high frequency device applications. For the manufacturing of SiC to semiconductor substrate, many researchers have studied on the subject of SiC polishing. However, SiC faces many challenges for wafer preparation prior to epitaxial growth due to its high hardness and remarkable chemical inertness. A smooth and defect free substrate surface is important for obtaining good epitaxial layers. Therefore, hybrid process, chemical mechanical polishing (CMP) has been proposed to achieve epi-ready surface. In this paper, the material removal rate (MRR) is investigated to recognize how long the CMP process continues to remove a damaged layer by mechanical polishing using 100 nm sized diamond, and the authors tried to find the dependency of mechanical factors such as pressure, velocity and abrasive concentration using single abrasive slurry (SAS). Especially, the authors tried to get an epi-ready surface with mixed abrasive slurry (MAS). The addition of the 25nm sized diamond in MAS provided strong synergy between mechanical and chemical effects resulting in low subsurface damage. Through experiments with SAS and MAS, it was found that chemical effect (KOH based) was essential and atomic-bit mechanical removal was efficient to remove residual scratches in MAS. This paper concluded that SiC CMP mechanism was quite different from that of relatively soft material to achieve both of high quality surface and MRR.
Authors: Han Chul Cho, Young Min Kim, Hyun Seop Lee, Suk Bae Joo, Hae Do Jeong
Abstract: Cu (copper) has been widely used for interconnection structure in integrated circuits because of its properties such as a low resistivity and high resistance to electromigration when compared with aluminum [1, 2]. Damascene process for the interconnection structure utilizes 2-steps CMP (chemical mechanical polishing). After 2-steps CMP process, many abrasive particles leave on the wafer surface, which should be removed in post-Cu CMP cleaning process. Cleaning efficiency affects directly on the subsequent process and device yield [3]. Therefore, cleaning of abrasive particles is the critical issue in semiconductor manufacturing.
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