Curvilinear mask is getting more widely used as a key technique for resolution enhancement with the progress of feature size shrinkage and multi-beam mask writers (MBMW) adoption. However, it is challenging to print curvilinear pattern accurately, which makes mask process correction (MPC) indispensable for curvilinear mask data preparation. It is known that pattern fidelity degrades at high curvature region by process blur. This degradation leads to various issues such as curvature loss and poor CD quality on printed curvilinear masks. Furthermore, due to anamorphic lithography systems, high-NA mask data is likely to contain patterns with higher curvatures compared to 0.33NA mask. Therefore, improving the accuracy of MPC on high curvature region is becoming more important. In this paper, we present a novel MPC method which deforms shape of high curvature region of any curvilinear pattern aggressively to achieve good fidelity. Using simulation and printed results of ellipse patterns with various curvatures, we will show that this MPC technique can improve pattern fidelity in regions of high curvature.
Since the design nodes gradually decreased and EUV production became reality, the data volume is continuously increasing due to Hard OPC & Flare Correction. Multi-Beam Mask Writers (MBMW) enabled mask exposures with curvilinear and circle pattern that have not been possible before. This soon led to an increase in the number of vertexes of design data and an increase in Mask Data Preparation turnaround times (MDP TAT). A data flow based on the newly developed MBW-2 file format was developed jointly with Nippon Control System and IMS nanofabrication and significantly improved MDP TAT. The effect was confirmed by verifying it with actual data using large-volume data and curvilinear data EUV masks exposed on MBMW. In addition, the MDP TAT was further improved by studying file write method. In this paper, we introduce the concept and application of the new data flow. Furthermore we will present the results on TAT and output file sizes. Finally, we will discuss each step in the data flow in detail.
KEYWORDS: Photomasks, Extreme ultraviolet, Information technology, Data processing, Data conversion, Data storage, Extreme ultraviolet lithography, Data corrections
The semiconductor industry's migration to EUV for the leading-edge nodes provides significant advantages and poses new challenges for the mask writers. The mask quality requirements for the leading-edge process technology call for ILT (Inverse Lithography Technology) and curvilinear patterns to improve the attainable resolution on wafers and extend the process windows. While single-beam writers cannot handle writing arbitrary curvilinear patterns without throughput penalty, multi-beam mask writers (MBMW) can easily print such patterns without degrading their throughput5,6. However, the transition to the curvilinear mask ILT significantly increases the layout complexity, posing a challenge for data transfer and storage systems as the file sizes increase substantially1. Traditionally, multi-beam-writers have been using a mask data input format derived from OASIS P44, namely OASIS.MBW 1.0/1.2, leading to multi-terabyte layouts. We present OASIS.MBW 2.1 as an efficient data format for curvilinear ILT masks. OASIS.MBW 2.1 enables a dramatic reduction in file size and vertex-density and preserves the qualities of OASIS.MBW 1.1/1.2 as well as quick and easy adaptability for the end-users. This is achieved by allowing the use of the OASIS P39 POLYGON RECORD in addition to the other OASIS.MBW 1.x properties, creating a hybrid format between OASIS P39 and P44 that provides a minimal file size comparable to OASIS P39 for pre- and post-fracture data operations at the fabs. Consequently, OASIS.MBW 2.1 provides the optimal combination of minimized file size and minimized required CPU time, thus enabling fast processing as well as a fast transfer for all applications.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.