Nanoimprint lithography is one of the candidates for NGL. Recently, the "S-FIL TM" (Step and Flash Imprint Lithography) has been developed by MII (Molecular Imprints, Inc.). Accordingly, it is necessary to build next-generation devices and study unit processes without delay. Because of good resolution, CD uniformity and LER, nanoimprint lithography is attractive. However, nanoimprint lithography (S-FIL) involves risks. In order to judge whether the S-FIL is applicable to the study of unit processes and test device fabrication, we had studied the feasibility of S-FIL technology.As a result of previous work, we obtained the results of basic evaluation and confirmed the applicability of nanoimprint lithography for unit process study and basic test device fabrication.However, application of nanoimprint lithography to various test devices requires the template resolution of 22nmHP, OL accuracy on multilayer resist, and defect density for various patterns. Therefore, in order to judge whether the S-FIL application is extendable to various test devices, we studied the characteristics of S-FIL.As a result of this work, we confirmed that the nanoimprint application is extendable to fabrication of various test devices. And as a result of basic evaluation, improvement of template resolution is confirmed and the value of 22nmHP is obtained. We confirmed the robustness of the alignment process. The defect density is related in pattern density and spread time. Thus, reduced DD without throughput loss is required.

This paper concerns the readiness of extreme ultraviolet lithography (EUVL) for high-volume manufacture based on accelerated development in critical areas and the construction of a process liability (PL) test site that integrates results in these areas. The overall lithography performance was determined from the performance of the exposure tool, the printability obtainable with the resist, mask fabrication with accurate critical dimension (CD) control, and correction technology for mask data preparation. The EUV1 exposure tool can carry out exposure over the full field (26 mm × 33 mm) at a resolution high enough for 32-nm line-and-space patterns when Selete Standard Resist 3 (SSR3) is used. Thus, the test site was designed for the full-field exposure of various pattern sizes [half-pitch (hp) 32-50 nm]. The CD variation of the mask was found to be as good as 2.8 nm (3σ); and only one printable defect was detected. The effect of flare on CD variation is a critical issue in EUVL; so flare was compensated for based on the point spread function for the projection optics of the EUV1 and aerial simulations that took resist blur into account. The accuracy obtained when an electronic design automation (EDA) tool was used for mask resizing was found to be very good (error ≤ ±2 nm). Metal wiring patterns with a size of hp 32 nm were successfully formed by wafer processing. The production readiness of EUVL based on the integration of results in these areas was evaluated by electrical tests on low-resistance tungsten wiring. The yield for the electrically open test for hp 50 nm (32-nm logic node) and hp 40 nm (22-nm logic node) were found to be over 60% and around 50%, respectively; and the yield tended to decrease as patterns became smaller. We found the PL test site to be very useful for determining where further improvements need to be made and for evaluating the production readiness of EUVL.

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Nanoimprint lithography has advantages such as good resolution, CD uniformity and LER. However, nanoimprint lithography involves risks. In particular, defectivity is the most critical issue for nanoimprint lithography. Above all, the "non-fill defects" dominate such defects for UV nanoimprint.At the filling process of imprint resist, the capillary force that occurs between an imprint-resist and surface of template plays an important role. Our experience, suggests there is a relationship between the filling characteristics and pattern size of template. We also think the resist properties and the environmental conditions such as atmosphere pressure play important roles in the filling process. This paper explains the filling process dependency on the properties mentioned above.We analyzed the filling process using fluid simulation. At first, we assumed several pattern sizes with the same pattern height. Then, the filling times were estimated for each pattern size with various resist properties and the environmental conditions. An important attribute of our simulation model is the consideration accorded to the dissolution of gas between the template and imprint resist.As a result, the filling time of smaller pattern was found to be shorter than that of larger pattern. The assumed patterns are space and via on template ranging in size from 22nm width to 1000nm-width. The pattern height is 60nm.In this paper, we studied characteristics of filling mechanism by using fluid simulation. The relations between CD and filling time were obtained. We found that the gas dissolution rate is the dominant parameter for filling time.

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