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Inashiki, Japan

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.

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.

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.

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.

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