Nihon Pall Ltd.

Ibaraki, Japan

Nihon Pall Ltd.

Ibaraki, Japan
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Takakura T.,Nihon Pall Ltd. | Tsuzuki S.,Nihon Pall Ltd.
IEEE International Symposium on Semiconductor Manufacturing Conference Proceedings | Year: 2017

As part of the study to investigate filter performance in the actual conditions, particle removal efficiency evaluation method of filters in isopropyl alcohol was developed. Three kinds of particles which exhibit each different charged state in the chemical, and the sizes of which are around 10 nm, were selected as test particles for the evaluation. Pall 10-nm-rated surface-modified PTFE membrane filter was evaluated with the particles. The result was compared with the removal efficiency in deionized water. Also, the effect of adsorption on the removal efficiency in the system was discussed. © 2016 IEEE.

Umeda T.,Nihon Pall Ltd | Daikoku S.,Nihon Pall Ltd | Tsuzuki S.,Nihon Pall Ltd | Murakami T.,Nihon Pall Ltd
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2017

OK73 thinner and cyclohexanone, both of which were spiked with metals were passed through Nylon 6,6 filter, varying flow rate, which include the conditions of both point-of-use and bulk filtrations. The influent and effluent metal concentrations were measured using ICP-MS for metal removal efficiency of the filtration. As a result, removal efficiency for some metals descended depending on the flow rate, while others maintained. Slower flow rate is recommended to maintain low metal concentration in bulk filtration based on the result. Metals in cyclohexanone were reduced at higher efficiency than in OK73 thinner, agrees with a metal removal model of hydrophilic adsorbent in organic solvent, evidenced in our previous paper. Further, metal reduction on 300 mm φ Si wafer after coating organic solvents with Nylon 6,6 filtration was evidenced with TREX analysis. © 2017 SPIE.

Umeda T.,Nihon Pall Ltd. | Takakura T.,Nihon Pall Ltd. | Tsuzuki S.,Nihon Pall Ltd.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2016

In this paper, we presented the filtration effects on block copolymers (BCP) that are commonly used in directed self-assembly lithographic (DSAL) imaging schemes. Specifically we focused on filtration effects on micro-contaminants such as metal ions and metal induced gels. Gel removal efficiency studies carried out with HDPE, Nylon and PTFE filters pointed out that Nylon 6,6 membrane is the most effective in removing gels in block copolymer (BCP) solutions. Metal removal efficiency studies were conducted using multistep filtrations such as repetitive filtration of single membrane material and combination of different type of membranes. Results showed that a combination of Nylon-6,6 and ion-exchange filters is highly effective in reducing metals such as Li, Mg and Al to > 99.99% efficiency. The mechanism of metal removal efficiency is discussed in detail. © 2016 SPIE.

Umeda T.,Nihon Pall Ltd. | Tsuzuki S.,Nihon Pall Ltd.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

The typical performance index of microelectronics-grade filter products is based upon mechanical sieving. However, adsorption also plays a critical role for reducing certain defects. To provide a more accurate metric, a complementary adsorption performance index is introduced for lithography process filters. In this study, heptylamine-substituted palladium nanoparticles were used to simulate the adsorptive characteristics of microbridge defect precursors. Adsorption kinetic parameters were calculated for Nylon 6,6 and HDPE filters that were challenged with the simulation particles. Nylon 6,6 media quantitatively demonstrated superior adsorptive retention characteristics. The new index is expected to guide both filter product development and filter recommendation for next generation lithography processes. © 2013 SPIE.

Umeda T.,Nihon Pall Ltd | Tsuzuki S.,Nihon Pall Ltd
Journal of Photopolymer Science and Technology | Year: 2014

Gel particle is a primal defect in block copolymer (BCP) layer in directed self assembly lithography(DSAL). We studied gel removal performance for various lithography process filters and found that nylon 6,6 membrane outperformed other membrane materials exerting adsorption performance similarly to the conventional chemical amplified resist (CAR) filtration. Contrary to the CAR, BCP is synthesized using metal polymerization initiator and the metal in the resist layer should be removed to prevent potential impact to the device integrity failure or the yield loss. We also studied metal reduction from the BCP solution using ion exchange filter and particle removal filters. As a result, ion exchange filter effectively reduced metals from BCP solution as expected. In addition, unexpectedly, nylon 6,6 membrane best reduced some metal species in the BCP solution. © 2014SPST.

Umeda T.,Nihon Pall Ltd. | Tsuzuki S.,Nihon Pall Ltd.
Journal of Photopolymer Science and Technology | Year: 2013

In order to study the filterability of block copolymer solutions (BCP) with 2 nm to 20 nm rated lithography process filters, the determination of hydrodynamic diameter by dynamic light scattering (DLS), block copolymer concentration determination using UV-Vis spectroscopy and molecular weight distribution measurement using gel permeation chromatography (GPC) were conducted. Hydrodynamic diameters by DLS were sufficiently small and this indicates filtration is feasible. And consistency of BCP concentration by UV-Vis spectroscopy and molecular weight distribution by GPC confirmed that HDPE 5, 2 nm rated filters and Nylon 6,6 20, 10 nm rated filters provided desired filtration without sacrificing critical performance of BCP solution. Based on the results, these filters are recommended for defect reduction in DSAL process which provides 1 X nm patterns. © 2013SPST.

Tsuzuki S.,Nihon Pall Ltd.
2015 Joint e-Manufacturing and Design Collaboration Symposium, eMDC 2015 and 2015 International Symposium on Semiconductor Manufacturing, ISSM 2015 - Proceedings | Year: 2015

Since the scale of semiconductor devices are continuously reducing, the control level of size and numbers of particles are also becoming stricter during the manufacturing process; the role of filtration is of great importance for the control of particle level. Thus, it is a critical issue to use an appropriate filter in each process tool. A criterion for selecting an appropriate filter is the removal rating, which claims the size of particles to be removed by the filter. The rating of the filters used for semiconductor device manufacturing is performed in the deionized water (DIW) at ambient temperature [1]. In the actual manufacturing process, however, the filters are used in various chemical and temperature, and in such condition, it is empirically known that removal efficiency of the filters differs from that in the standard atmosphere (i.e. DIW at ambient temperature). Thus, it is important to know the actual particle removal efficiency (PRE) in the actual chemical. In the semiconductor cleaning process, high temperature sulfuric acid is commonly-used chemical, and there are some studies on PRE evaluation of filters in the chemical: One is in 120 °C sulfuric acid using a liquid particle counter (LPC) which can detect 60 nm and larger particles [2], and another is in 150 °C sulfuric acid using a LPC which can detect 40 nm and larger [3]. However, the measurement ranges of these LPCs are coarser than the filter rating used for the leading-edge semiconductor processes (< 20 nm), and finer measurement range would be preferred. In this study, we conducted PRE evaluation of filters in high temperature sulfuric acid using a LPC with sensitivity of 30 nm which is the currently finest one available in the chemical, and discussed the effect of the measurement range difference on PRE. Also, an effect of flow rate on the PRE was studied. © 2015 Taiwan Semiconductor Industry Association.

Umeda T.,Nihon Pall Ltd. | Tsuzuki. S.,Nihon Pall Ltd.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

It is known that DUV resist filtration using Nylon 6,6 membrane significantly reduces microbridge defects. Previous work has described a method to determine an adsorption performance index using modified metal nanoparticles, which simulate interactions with microbridge defect precursors. In this paper, the effects of filter grade, filter material, and solvent type on adsorptive retention are explored. The adsorption rate in Nylon 6,6 40 nm filter was observed to be greater in both lower-LogPow and lower-viscosity solvents, possibly providing a direction for improved filtration performance based on the solvent properties. The complementary adsorption kinetics parameters give a more accurate suggestion for the filter performance in lithography applications combined with the conventional sieving filter ratings. © 2014 SPIE.

Umeda T.,Nihon Pall Ltd. | Morita A.,Dainippon Screen Manufacturing Co. | Shimizu H.,Dainippon Screen Manufacturing Co. | Tsuzuki S.,Nihon Pall Ltd.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

Wet particle reduction during filter installation and start-up aligns closely with initiatives to reduce both chemical consumption and preventative maintenance time. The present study focuses on the effects of filter materials cleanliness on wet particle defectivity through evaluation of filters that have been treated with a new enhanced cleaning process focused on organic compounds reduction. Little difference in filter performance is observed between the two filter types at a size detection threshold of 60 nm, while clear differences are observed at that of 26 nm. It can be suggested that organic compounds can be identified as a potential source of wet particles. Pall recommends filters that have been treated with the special cleaning process for applications with a critical defect size of less than 60 nm. Standard filter products are capable to satisfy wet particle defect performance criteria in less critical lithography applications. © 2014 SPIE.

Sumiya M.,Nihon Pall Ltd.
ICPT 2014 - Proceedings of International Conference on Planarization/CMP Technology 2014 | Year: 2015

The objective of this study is to propose a laboratory test method for confirming LPC (large particle count) reduction by porous membrane filters, which are generally thought to have higher particle removal performance than melt-blown filters. CMP slurries were filtered by porous membrane filters and a nonwoven depth filter. Then LPC reduction of the filtrates was estimated by a particle counter in conjunction with control membrane test, in which pressure drop increase of a filter (a control membrane) was an indicator of LPC. Difference of LPC for filtrates from each type of filter was small by the particle counter and significant by the control membrane method, but with the porous membrane filter exhibiting lower LPC by the both methods. The results demonstrate that a combination of particle counter and control membrane method can reveal difference of filter performance in LPC reduction with confidence. Further, to show pressure drop increase could be an indicator of LPC, pressure drop increase of the control membrane enhanced by large particles was examined. © 2014 IEEE.

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