Reticle SEM specifications required for lithography simulation

Kariya, Mitsuyo; Yamanaka, Eiji; Tanaka, Satoshi; Ikeda, Takahiro; Yamaguchi, Satoru; Itoh, Masamitsu; Kobayashi, Haruo; Kawashima, Tsukasa; Narukawa, Shogo

doi:10.1117/12.617130

Cited by 3 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Consequently, the mask quality assurance method requires hotspots management in addition to conventional management, such as management of global and local CD variation and defects. The "hotpot-based mask guarantee" method had been presented as "flexible mask specification" 2 , "dose-MEF based hotspot selection strategy" 3 and "requirement for hotspot mask SEM images" 4 . However, simulation accuracy is at present insufficient to realize hotspot-based mask quality assurance.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of lithography simulation model accuracy for hotspot-based mask quality assurance

et al. 2007

Self Cite

View full text Add to dashboard Cite

Mask topography has effects on important components of optical image formation at 45nm node and beyond 1 , and therefore, the lithography simulation model required for hotspot-based mask quality assurance has to incorporate mask topography effects. Since calculation of mask topography effects involves physical phenomena different from those encountered in resist processes, we propose the concept of the mask & resist dual fitting method that splits the general experimental model into the experimental resist model and the experimental mask model. To realize mask & resist dual fitting, we have developed an experimental mask model, namely, the mask topography approximate model. The mask & resist dual fitting method can improve model fitting accuracy and improve prediction accuracy at hotspots.

show abstract

Section: Introductionmentioning

confidence: 99%

Evaluation of lithography simulation model accuracy for hotspot-based mask quality assurance

et al. 2007

Self Cite

View full text Add to dashboard Cite

show abstract

“…For quality assurance of mask pattern, a metrology of complicated 2D OPC patterns has been required. In our previous report (1) (2) (3) , we proposed a lithography simulation based on edge extraction from a fine pixel SEM image of an actual photomask. This method is a very effective one to evaluate quality of 2D OPC mask patterns.…”

Section: Introductionmentioning

confidence: 99%

Fine pixel SEM image for EUV mask pattern 3D quality assurance based on lithography simulation

et al. 2010

Self Cite

View full text Add to dashboard Cite

Optical proximity correction (OPC) is still an essential technology for critical dimension (CD) control in Extreme Ultra Violet (EUV) lithography. For quality assurance of EUV mask pattern, a metrology of complicated two-dimensional (2D) OPC patterns is important. Moreover, the side wall angle management of a mask pattern becomes important in EUV lithography because exposure light is diagonally incident on a mask pattern. The quality assurance of EUV mask pattern requires the pattern edge extraction including the side wall angle. We had developed an SEM which is one of the key factors of this three-dimensional (3D) quality assurance method. The high accuracy measurement of a side wall angle using Tilting and Moving Objective Lens (T-MOL) is most feature of this SEM. Employing this SEM, we will add the side wall angle information to the system for guaranteeing 2D OPC patterns before shipping the mask to a wafer factory. In this paper, we report the study about the management of the side wall angle of an EUV mask pattern. And then we report the evaluation results of the side wall angle measurement system with a tilted fine pixel SEM image that satisfies the requirement of the management.

show abstract

Virtual lithography system to improve the productivity of high-mix low-volume production

et al. 2007

Self Cite

View full text Add to dashboard Cite

This paper proposes a new virtual lithography system to improve the productivity of high-mix / low-volume production. In the case of the conventional technique, product mask and wafer are used to determine a focus-exposure-matrix (FEM) exposure condition. The conventional technique is a "send-ahead" process involving exposure, metrology and data analysis that decreases productivity of manufacturing. In the case of low-volume/high-mix ASIC manufacturing, such a send-ahead process is particularly time-consuming and costly. Moreover, the exposure condition setting imposes a huge workload that is desirable to be avoided from the viewpoints of cost and TAT. Thus, a new methodology to determine exposure dose conditions for each mask in high-mix / low-volume production is required. In this paper, we propose a virtual lithography system to eliminate send-ahead exposure. Firstly, to improve wafer CD prediction accuracy, we rebuild the system, thereby transforming it from a training-based system to a simulation-based system. To make simulation models, we use a golden mask, which is not a product mask. Secondly, exposure conditions are determined by considering 2D patterns including hotspot patterns. Thirdly, the lithography simulation is carried out for each exposure tool. Using the golden mask, we calibrate simulation models for each exposure tool 1-3 . Various patterns including hotspots likely to become fatal errors for circuit reliability due to process proximity effects are considered. The virtual system provides optimal exposure parameters according to product and layer, considering longterm variation of exposure tool conditions. By developing this system, TAT and cost for the determination of exposure parameters will be improved. Elimination of send-ahead wafers can reduce TAT from mask delivery to exposure condition setup in high-mix / low-volume production. Drastic cost reduction is realized in high-mix / low-volume production.

show abstract

Reticle SEM specifications required for lithography simulation

Cited by 3 publications

References 0 publications

Evaluation of lithography simulation model accuracy for hotspot-based mask quality assurance

Evaluation of lithography simulation model accuracy for hotspot-based mask quality assurance

Fine pixel SEM image for EUV mask pattern 3D quality assurance based on lithography simulation

Virtual lithography system to improve the productivity of high-mix low-volume production

Contact Info

Product

Resources

About