Kuninori Nishizawa

Advanced mask rule check (MRC) tool

As patterns on photomasks are getting more complex due to RET technologies, mask rule check (MRC) has become an essential process before manufacturing photomasks. Design rule check (DRC) tools in the EDA field can be applied for MRC. However, photomask data has unique characteristics different from IC design, which causes many problems when handling photomask data in the same way as the design data. In this paper, we introduce a novel MRC tool, SmartMRC, which has been developed by SII NanoTechnology in order to solve these problems and show the experimental results performed by DNP. We have achieved high performance of data processing by optimizing the software engine to make the best use of mask datas characteristics. The experimental results show that only a little difference has been seen in calculation time for reversed pattern data compared to non-reversed data. Furthermore, the MRC tool can deal with various types of photomask data and Jobdec in the same transparent way by reading them directly without any intermediate data conversion, which helps to reduce the overhead time. Lastly it has been proven that result OASIS files are several times smaller than GDS files.

IP protection of mask data by rebuilding the design hierarchy using OASIS format

In this paper we present new development of intellectual properties(IP) protection software using OASIS format. By taking advantage of repetition presentation of OASIS, it becomes possible to express arrayed patterns without any generation of new cells, which also brings less overhead and further compaction of the result file. As a result, we could rebuild the hierarchy without cell generation and reduce the output file size. The experimental results show that there are no redundant cells generated and the file size has become 5 to 8 times smaller than conventional methods.

Effective IP protection method of mask data using OASIS format

We have been developing intellectual properties (IP) protection software using OASIS format. In the Photomask Technology 2004 we presented that by taking advantage of repetition presentation of OASIS, it becomes possible to express arrayed patterns without any generation of new cells, which also brings less overhead and further compaction of the result file. As a result, we could rebuild the hierarchy without cell generation and reduce the output file size. In this paper, additionally we have applied a unique compression function CBLOCK defined in OASIS format. CBLOCK can compress any part of OASIS file. The experimental results show that there are no redundant cells generated and the file size has become approximately 20 times smaller than conventional methods.

EPL mask data conversion system EPLON

EPLON is the name of a system that we have been developing as a data conversion system for EPL masks in order to meet the requirements of EPL stencil masks. In our paper we presented in PMJ2002, we proved that our system could convert the whole chip data. However we still had some problems to overcome, one of which is a problem of conversion time and another issue is a data volume problem. This paper presents the features of our multi process computation method and the data compaction with building a hierarchy from the flattened data.

From GDSII to OASIS : Practical support tools for data processing flow transition

OASIS format has begun to be accepted in the field of mask data processing gradually. Major EDA venders have announced their support of OASIS format and new versions of EDA tools which can handle with OASIS files have been shipped one by one. Still, there are great difficulties to convert all the data processing flow from old GDSII to new OASIS. One of the major issues is a problem of verification. Since all the tools have not been completely stable and reliable, there should be a method to verify whether the data is converted to OASIS without any problems. In addition to that, the integrity of the OASIS files itself have to be checked. In general, OASIS has two aspects for the mask industry. One is a role as a new replacement of GDSII. The other is OASIS.VSB, which is a unified format defined for the description of fractured EB data. SII NanoTechnology has been developing a new software package called SmartOASIS. SmartOASIS provides lots of practical functions to enable easy transition of data processing flow from conventional GDSII or EB formats to OASIS.

New placement algorithm of contact layer patterns for NGL stencil complementary masks

The contact layer has been said to be the first application of NGL technologies such as EPL or LEEPL, in which stencil masks are used. Since the computation time depends on the number of edges of patterns, contact layer data which contains many rectangles takes very long time to process. Actually it has been reported that the complementary split of the contact layer patterns take longer time than any other layer like metal layer or poly line layer due to the numerous small rectangle patterns in the contact layer. This paper presents a new innovative algorithm, called gravity point method, to dispatch contact patterns very quickly onto complementary masks. The results show that the new gravity point method algorithm is effective for the huge size of contact layer data.

EPL data conversion system EPLON

We have developed the EPL mask data conversion system EPLON. It provides comprehensive capabilities necessary for the data conversion of EPL masks. This paper presents the features of each function and the evaluation result of data conversion with actual data on a full chip level. The result shows that the whole data conversion is possible within reasonable time for huge data. We also propose a new format for describing EPL mask data to deal with the huge size of EPL mask data after conversion. The format is called the EPLM format and it contains one main file and multiple subfield files.