Mask data preparation (MDP) is a complicated process because many kinds of EB data files and jobdeck data files are used in mask manufacturers and EB data files continue to become bigger. Therefore we have developed unified mask data formats for Variable-Shaped-Beam (VSB) EB writers with efficient data compaction. The unified mask data formats are composed of a pattern data format for EB writers named "NEO" and a layout format named "MALY". We released NEO and MALY on April 2003. To evaluate NEO and MALY, we have made a prototype system of MDP such as a converter from design data to NEO/MALY and converters from NEO/MALY to each EB data. We have evaluated about functions and performance of the MDP flow using real design data in device manufacturers. As a result, some improvements in NEO and MALY were achieved and we have revised the specification of NEO and MALY as the final version. We have confirmed that NEO and MALY can be used for a set of unified mask data formats among VSB EB writers and can reduce complexity of mask data handling in mask manufacturers. They will be put to practical use in MDP flow.
Mask data preparation is a complicated process because many kinds of EB data files and jobdeck data files are used in mask manufacturers and EB data files continue to become bigger. Therefore we have started to develop new mask data format with efficient data compaction and unification among Variable-Shaped-Beam (VSB) EB mask writers. We have proposed the unified mask pattern data format for EB writers named "NEO"<sup>1</sup> in the 22nd annual BACUS symposium. We have proposed the unified mask layout format named "MALY" 2 and the high-compression data processing system3 for NEO in Photomask Japan 2003, too. Then we have decided to develop an enhanced mask data preparation system using NEO<sup>4</sup> and MALY<sup>5</sup>. This system has common MDP functions not to be related to each EB writer. That would be effective in reducing mask data handling cost. In this paper we introduce the abstract of NEO and MALY and new mask data preparation system using NEO and MALY.
Recently as the node size gets smaller into deep sub-micron, both chip designers and mask manufacturers have faced great problems as follows: (1) Explosion of the data size; (2) Further data complexity due to OPC or PSM; (3) Increasing numbers of data formats. Since these problems directly lead to the increase of the mask costs, we have thought that they need to be overcome from the viewpoint of data processing as well. Selete have made a proposal of a next generation EB handling format, called 'NEO', in order to cope with these issues. The greatest feature of NEO is its compaction capability of the data description and it is expected that the chip data size could be reduced far smaller than in any other existing EB formats. We have been working on the NEO project in cooperation with Selete and developed a new system 'GDS2NEO', which converts the conventional layout data described in GDSII to the NEO-formatted data. We also investigated the compaction efficiency of NEO with several sets of actual layout data using GDS2NEO. As the result, we have proved that NEO has an excellent efficiency of data compaction and GDS2NEO has achieved a satisfactory performance of data conversion. In this paper we present the concept of NEO format, the data processing flow and the basic algorithm of GDS2NEO, the experimental results and the future plans.
Mask data preparation is a complicated process because many kinds of pattern files and jobdeck files flow into mask manufacturers. This situation has a significant impact on data preparation operations especially in mask manufacturers. In this paper, we propose a solution to this problem: use of unified mask data formats for EB writers and a model of data preparation flow from a device manufacturer to an EB writer. The unified formats consist of pattern data format named "NEO", and mask layout format named "MALY".
NEO is a stream format which retains upper compatibility to GDSII and has higher compression rate than GDSII. NEO is intended to be a general input format of Variable-Shaped-Beam (VSB) mask writers in principle, not particularly designed for any specific equipment or software. Data conversion process between mask writers being taken into account, NEO requires some constraints for VSB mask writers, such as removal of overlapping figures. Due to many differences in jobdeck syntax and functions among mask writers, it is a complicated task to edit or modify a jobdeck, and convert it into another format. MALY is a text-based format whose purpose is to standardize mask layout information among mask writers. This unification of mask layout information optimized for EB writers is expected to reduce workload of mask data preparation significantly. Besides the information described in MALY, some other information specific to the target EB writer, such as drawing parameters, has to be prepared separately. This paper illustrates a model of data flow and benefits of using these unified formats. The format and the data flow are effective in reducing data handling cost, providing flexible data handling solution. Applying the handling flow using NEO and MALY would result in reducing the load on mask manufacturers. Moreover, device manufacturers would be freed from the need to specify the mask writer to be used when ordering masks to mask manufacturers.
Proc. SPIE. 4889, 22nd Annual BACUS Symposium on Photomask Technology
KEYWORDS: Data compression, Data modeling, Manufacturing, Data processing, Software development, Photomasks, Optical proximity correction, Data conversion, Electronic design automation, Standards development
Mask data preparation (MDP) systems are becoming more and more complicated due to increasing demand for higher resolution, and more commonly adopted technique of optical proximity correction (OPC). Conventionally, as a standard format to describe mask patterns, GDSII has been widely used in the EDA field as well as in the mask production field. These days, however, GDSII is revealing its disadvantage in terms of efficiency in data compaction. On the other hand, mask pattern data in a variety of formats, including GDSII, are flowing into mask manufacturers, and this is making their process extremely complicated.
In this paper, we propose a unified format, tentatively named "GDSII-NEO." GDSII-NEO is designed to retain GDSII upper compatibility in consideration of the utilization of existing GDSII data and to have several times higher compression rate than GDSII. GDSII-NEO can be seen as a multi-purpose format used widely in the EDA and mask field. An intended use, among others, of this format is to describe the pattern data fed into Electron Beam (EB) mask writers.