JungChan Kima, HyunJo Yanga, JooKyoung Songa, DonGgyu Yima, JinWoong Kima, Toshiaki Hasebeb, Masahiro Yamamotob
aMemory Research & Development Division, Hynix Semiconductor Inc., Korea
bNGR Inc., Japan
The downscaling of the feature size and pitches of the semi-conductor device requires the improvement of device characteristics and high yield continuously. In lithography process, RET techniques such as immersion and polarization including strong PSM mask have enabled this improvement of printability and downscaling of device. It is true that optical lithography is approaching its limit. So other lithographic technique such as EUV is needed but the application is not yet available. In this point of view, the realization of lithography friendly layout enables good printability and stable process. And its scope is being enlarged and applied in most semi-conductor devices. Therefore, in order to realize precise and effective lithography friendly layout, we need full chip data feedback of design issue, OPC error and aberration and process variables.
In this paper, we report the results of data feedback using new DFM verification tool. This tool enables full chip inspection through E-beam scan method with fast and accurate output. And these data can be classified with each item for correction and stability check through die to database inspection. Especially in gate process, total CD distributions in full chip can be displayed and analyzed for each target with simple method. At first we obtain accuracy data for each target and CD uniformity from hundreds of thousands of gate pattern. And second we detect a delicate OPC error by modeling accuracy and duty difference. It is difficult to get from only measurement of thousands pattern. Finally we investigated specific pattern and area for electrical characteristic analysis in full chip. These results should be considered and reflected on design stage.
Key words: DFM, OPC, Design, Die, Database