Photomask Japan最新文献

{"title":"Study of high-transmission PSM for lithographic performance and defect control","authors":"K. Matsui, Naoto Yonemaru, Y. Kojima, Tatsuya Nagatomo, M. Yamana","doi":"10.1117/12.2601771","DOIUrl":"https://doi.org/10.1117/12.2601771","url":null,"abstract":"ArF lithography is still applied to the majority of critical layers, even with increasing of extreme ultraviolet lithography in leading-edge production. As wafer design shrinks, conventional 6% phase shift mask (PSM) becomes hard to meet the ArF lithography requirements especially for array dot on mask (hole on wafer). Therefore, transmission dependency was evaluated by mask 3D simulation, and it was found that 30% transmission has the best lithographic performances for array dot. Based on these results, mask blank and mask making process for new 30% PSM were developed. Wafer printability test using negative tone development demonstrated that new 30% PSM has better process window and mask error enhancement factor (MEEF) than conventional 6% PSM for array dot (hole on wafer). To investigate further application of new 30% PSM, lithography performances of various patterns were evaluated by mask 3D simulation and aerial image measurement system (AIMSTM). The results indicated that new 30% PSM has larger lithography margin than 6% PSM for iso dot, iso line and logic pattern. Additionally, wafer printability test demonstrated that new 30% PSM has better process window than 6% PSM for iso dot. Defect control is also an important factor in high volume manufacturing. Therefore, it is necessary to evaluate the repairability and printability of the defects on new 30% PSM. We repaired various types of defects by electron-beam repair tool and confirmed the repairability by AIMS. And the defect printability of new 30% PSM and 6% PSM to critical dimension (CD) on wafer was evaluated by program defect mask that has pin dot, extrusion and intrusion defects.","PeriodicalId":138407,"journal":{"name":"Photomask Japan","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121856033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrogen damage and cleaning evaluation of Mo/Si multilayer using high-power EUV irradiation tool","authors":"T. Harada, Ayato Ohgata, Shinji Yamakawa, Takeo Watanabe","doi":"10.1117/12.2601080","DOIUrl":"https://doi.org/10.1117/12.2601080","url":null,"abstract":"At EUV lithography, an EUV mirror can be easily contaminated with carbon. This carbon contamination causes the reflectance drop of the Mo/Si multilayer mirror. For the carbon-contamination cleaning, hydrogen gas is introduced at a pressure of a few Pascal in the EUV exposure tool. However, during this process, the hydrogen damage would be caused on a Mo/Si multilayer, which would decrease EUV reflectance of the multilayer. The cleaning rate and damage threshold of hydrogen pressure and EUV dose were not well known. Therefore, an EUV irradiation tool in hydrogen atmosphere is developed and installed at the BL09 beamline of the NewSUBARU synchrotron light facility to evaluate the irradiation durability and cleaning effect of the Mo/Si multilayer under these conditions. The EUV-irradiation intensity was up to 6 W/cm2, and hydrogen pressure was up to 70 Pa. The contamination was occurred at the low-hydrogen-pressure conditions from 0 to 5 Pa. The contamination was not occurred at the high-hydrogen-pressure condition of 20 and 68 Pa. In addition, the sample with many particles on the surface was damaged by the EUV-induced plasma.","PeriodicalId":138407,"journal":{"name":"Photomask Japan","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126338428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stereophonic projection lithography using parabolic mirrors","authors":"T. Horiuchi, Hiroshi Kobayashi","doi":"10.1117/12.2597232","DOIUrl":"https://doi.org/10.1117/12.2597232","url":null,"abstract":"Stereophonic lithography applying a magic-mirror optics composed of faced parabolic mirrors is proposed. In the magic mirror system, a real image of an object placed on the base of the lower mirror is formed at the aperture center of upper mirror as if an actual object is floating in the air. The image is formed by illuminating the object by the downward light supplied through the upper mirror aperture. In the new optics originated in this research, a lower mirror with an aperture similar to the upper mirror is used, and the object held at the center of the lower mirror aperture is illuminated obliquely by the upward light supplied through the lower mirror aperture. At first, using reflective objects, image formations were demonstrated. When an object was placed at various height of the optical axis, an image almost similar to the object was projected successfully in a wide height range of the object. The size and the height position of the image were almost regularly changed according to the axial height shift of the object. However, image contrasts sufficiently high for the lithographic patterning were not obtained. For this reason, transparent objects were tried next, and the illumination light was adjusted as most of the light rays hit the middle parts of the upper mirror surface. As a result, considerably high-contrast images were formed. Although some distortions were observed in image shapes, feasibility of the new stereophonic projection system was confirmed. The new technology is prospective.","PeriodicalId":138407,"journal":{"name":"Photomask Japan","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129809202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proposal of new style defect quality assurance for flat panel display photomask","authors":"Shinya Hamasuna, Taichi Ozaki, Kenichi Kanaya","doi":"10.1117/12.2598157","DOIUrl":"https://doi.org/10.1117/12.2598157","url":null,"abstract":"Since the mid-2010s, mobile organic light emitting diode (OLED) panels have increased the demand for increased resolution in Flat Panel Display (FPD) photomasks [1]. In response to this demand, a 1.5 um Line and Space target exposure system for 800ppi OLED panels ware released in the mid-2010s. In addition, exposure system manufacturers are developing 1.2um Line and Space target exposure systems to produce ultra-high-definition OLEDs in the 800-1000ppi range [2]. While photomask manufacturers are required to have defect assurance capabilities for the next generation design, there is no standard industry roadmap in the field of FPD lithography. We believe that what is really necessary for the OLED panels manufacturer is to ensure that the pattern on the photomask is transferred to the OLED panel without any problems. Instead of the assurance based on the size of the defect on the photomask, we propose a new type of photomask assurance, which is the assurance for the pattern transfer to the OLED panel by the photomask maker. In this report, we will report on our new type FPD photomask assurance proposal.","PeriodicalId":138407,"journal":{"name":"Photomask Japan","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116749835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The application of reticle analyzer in DRAM fab","authors":"Asei Chou, Wenhao Hsu, Andy Lan, Jason Fang, Claire Lu, Harper Yu, Zeyu Lei, Catherine Li, Steven Liu, V. Tolani","doi":"10.1117/12.2598020","DOIUrl":"https://doi.org/10.1117/12.2598020","url":null,"abstract":"In modern advanced IC fabs, reticle management is essential for process control and yield management, since any reticle issue can potentially impact thousands of wafers, resulting in a huge economic loss. For reticle caused issues, the possibility of human mistakes made in defect disposition has dramatically increased as the defects on reticles become more complicated. The difficulty in defect disposition originates from smaller critical dimension (CD) and complex pattern designs like aggressive OPC and SRAF. Conventionally, defect disposition after reticle inspection is done by operators or engineers, and defects are evaluated based on engineers’ experience or AIMS tool, which are high risk and time-consuming methods. Use of automated defect disposition solutions has been reported in some photomask shops, but in DRAM fabs, an efficient and accurate defect disposition system is not yet present. In collaboration with KLA, Changxin Memory Technology (CXMT) accessed and utilized KLA’s Reticle Analyzer (RA), an intuitive web-based analysis interface that integrates Automatic Defect Classification (ADC), Lithographic Printability Review (LPR), and Defect Progress Monitor (DPM) to overcome reticle defect disposition difficulties. The comprehensive analytics tool systematically disposes all defects detected by KLA reticle inspection systems, eliminating human error in defect classification and providing 99.5% accuracy without under-classifying any defects. Furthermore, CXMT studied the LPR solution for multiple critical layers with programmed-defect masks, then verified the simulated LPR results in CD error (CDE). The correlation between LPR results and wafer printing results shows accurate CDE prediction in high volume production. Additionally, DPM was used to generate statistical process control like charts for reticle defectivity. This study shows that the integrated RA software offers a modern solution for wafer fabs that automates reticle defect management and shortens time to decision for engineers.","PeriodicalId":138407,"journal":{"name":"Photomask Japan","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116427513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanoimprint performance improvements for high volume semiconductor device manufacturing","authors":"R. Tanaka, Mitsuru Hiura, Yukio Takabahashi, Atsushi Kimura, Hiroshi Morohoshi, Y. Suzaki, Takahiro Matsumoto, N. Roy, Anshuman Cherala, Jin Choi","doi":"10.1117/12.2599713","DOIUrl":"https://doi.org/10.1117/12.2599713","url":null,"abstract":"Imprint lithography is an effective and well-known technique for replication of nano-scale features. Nanoimprint lithography (NIL) manufacturing equipment utilizes a patterning technology that involves the field-by-field deposition and exposure of a low viscosity resist deposited by jetting technology onto the substrate. The patterned mask is lowered into the fluid which then quickly flows into the relief patterns in the mask by capillary action. Following this filling step, the resist is crosslinked under UV radiation, and then the mask is removed, leaving a patterned resist on the substrate. The technology faithfully reproduces patterns with a higher resolution and greater uniformity compared to those produced by photolithography equipment. Additionally, as this technology does not require an array of wide-diameter lenses and the expensive light sources necessary for advanced photolithography equipment, NIL equipment achieves a simpler, more compact design, allowing for multiple units to be clustered together for increased productivity. Previous studies have demonstrated NIL resolution better than 10nm, making the technology suitable for the printing of several generations of critical memory levels with a single mask. In addition, resist is applied only where necessary, thereby eliminating material waste. Given that there are no complicated optics in the imprint system, the reduction in the cost of the tool, when combined with simple single level processing and zero waste leads to a cost model that is very compelling for semiconductor memory applications. DRAM memory is challenging, because the roadmap for DRAM calls for continued scaling, eventually reaching half pitches of 14nm and beyond. For DRAM, overlay on some critical layers is much tighter than NAND Flash, with an error budget of 15-20% of the minimum half pitch. For 14nm, this means 2.1-2.8nm. DRAM device design is also challenging, and layouts are not always conducive to pitch dividing methods such as SADP and SAQP. This makes a direct printing process, such as NIL and attractive solution. The purpose of this paper is to review the performance improvements related to overlay and introduce edge placement error analysis for NIL. Improvements in overlay include an extension in the range for high order distortion correction and improvements in control methods such as imprint force, mask to wafer tip/tilt and wafer zone pneumatics near the wafer edge. We also introduce the pattern transfer scheme used to etch features with half pitches below 20nm.","PeriodicalId":138407,"journal":{"name":"Photomask Japan","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134313127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient VIA position optimization for yield enhancement","authors":"Hsi Min Liu, Yen Po Tseng, Chia Chien Lee, Chun-Sheng Tsai, Xiang Fang, Shou-Yuan Ma, H. Liao, Ling-Chieh Lin, A. Pearson, Manish Khanna","doi":"10.1117/12.2597680","DOIUrl":"https://doi.org/10.1117/12.2597680","url":null,"abstract":"We introduce a new algorithm (DFM Via Shift) to reposition vertical interconnect access (VIA) design patterns, considering the retargeted metal (both upper and lower layer) pattern, the user-defined max-shifting range, and the VIA design rule, for the purpose of achieving maximum metal coverage of VIAs. The DFM Via Shift algorithm considers VIAs that interact with each other based on spacing rules as a VIA cluster. All VIAs in a cluster are co-optimized, allowing for fully-covered VIAs with good positioning to be shifted to allow other, more critical VIAs to be optimized in some scenarios. We present the results of our research showing that the overall metal coverage of VIAs in 25nm node test chips can be significantly improved with repositioning. Nearly 95% of VIAs exposed out of metal after retargeting can be optimized to new, fully-covered positions in one of the test cases of the advanced node.","PeriodicalId":138407,"journal":{"name":"Photomask Japan","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115017542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stability of CD off-target: analysis","authors":"P. Nesládek, F. Schurack, Olga Hortenbach, Michael Finken","doi":"10.1117/12.2599510","DOIUrl":"https://doi.org/10.1117/12.2599510","url":null,"abstract":"Narrowed CD specifications coupled with very tight cycle time requirements have resulted in search for improvement opportunities in CD stability and tuning options for mask fabrication unit processes, including pattern generation, resist development and etch, which may yield narrower scattering band of CD off-target (CDO) of final products. Targeting models are already in productive use at AMTC, accounting for different mask and blank types, clear field, resist type, pattern type and many other parameters. This targeting model is static however, and changes in the CD performance of contributing factors must be adjusted manually when CD drift inevitably occurs. In the past, several approaches to introduce time-based corrections were pursued. Correction of step function of the resulting CDO caused by e.g. resist lot change is the easier task, due to the fact that such factors can be closely analyzed prior to productive use by test, and offset accounting for the individual factor can be introduced. More troubles cause factors, whose effects on CDO is smooth and can be observed as long-term drift in the CDO. The CD drift is frequently of very different origin and effects of several factors are overlapping in time. By measuring the final CD on the products, we can see only the ‘envelope’ of all the effects. To target such factors, we need to identify their root cause and ideally an easy-to-monitor indicator. In this paper we show an analysis approach to identify the most significant and vital indicators to process bias. Analysis of production data covering several manufacturing steps including metrology over more than three years was performed. Using machine learning methods, a “big data” set is reduced, and the most appropriate model is selected using statistical methods. Criteria for selection of factors were significance level in analysis of variance and the distribution of residuals was used for model comparison. Based on these factors a model of the etch contribution to the CD was established, describing the variation of the etch process for a virtual mask with constant clear field, resist sensitivity and absorber composition and thickness. This model is based on the process data collected at the etch process during processing of each mask processed with the same recipe. Monitoring this time trend of the “modelled etch bias” gives very fast feedback about the stability of the etch process and evolution of the etch contribution to CD. This data is used to trigger appropriate corrective actions to further stabilize the manufacturing process.","PeriodicalId":138407,"journal":{"name":"Photomask Japan","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123477129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Model-driven rule-based mask process correction","authors":"W. Kwok, Johnny Yeap, Sebastian Munoz, Seurien Chou, Tokiharu Sekiya, Hari Konnanur","doi":"10.1117/12.2601035","DOIUrl":"https://doi.org/10.1117/12.2601035","url":null,"abstract":"MPC has been a technology enabler since 32nm technology node, and the number of mask layers receiving MPC increases as technology node advances. Model-based Mask Process Correction (MB-MPC) has evolved from correction based on short-range Gaussian to full Machine Learning (ML) based model and correction. Model-based MPC has demonstrated efficacy in reducing mask error on advanced nodes, but often requires extensive computing resource to achieve the stringent mask fidelity and Critical Dimension (CD) requirements. On the other hand, rule-based Mask Process Correction (RB-MPC) has the advantage of fast turn-around time. This paper presents an approach to rule-based MPC that seeks to extract the maximum benefits of model-based MPC. The rules cover critical geometrical ‘building blocks’ such as lines, contacts, line-ends, notches. Derivation of the rules is guided by a mask process model. The goal of RB-MPC is to mitigate the long runtime of MB-MPC while minimizing loss in patterning fidelity. We will describe the methodology of rule derivation, implementation, and verification of RB-MPC. The RB-MPC approach meets accuracy requirements for 32-22nm technology nodes. For more advanced technology nodes, a hybrid RB-MB-MPC recipe is proposed to achieve both high accuracy and fast runtime.","PeriodicalId":138407,"journal":{"name":"Photomask Japan","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116850057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of high throughput EUV mask pattern inspection technologies using multi e-Beam optics","authors":"Tadayuki Sugimori, R. Ogawa, H. Takekoshi, John G. Hartley, David J. Pinckeny, A. Ando, K. Ishii, Chosaku Noda, N. Kikuiri","doi":"10.1117/12.2598235","DOIUrl":"https://doi.org/10.1117/12.2598235","url":null,"abstract":"High volume manufacturing of semiconductors using extreme ultraviolet lithography (EUVL) is off to a good start, and development of high-NA EUVL tool has started; however, EUV mask pattern inspection, one key technology supporting EUVL, is still not ready in terms of fully satisfying customers' major requirements, such as 1) defect sensitivity, 2) throughput, and 3) cost of ownership (CoO). There are three tool candidates that have the potential of meeting these requirements: optical inspection, actinic inspection, and e-beam inspection. The resolution of the optical inspection tool has almost reached its limit. The actinic inspection tool satisfies both defect sensitivity and throughput requirements, but the cost is high and it needs to support D2DB inspection capability. The e-beam tool has high resolution and sensitivity, but its low throughput which is a key issue. With this background, NuFlare has optimized its multi e-beam optics system to inspect EUV masks, and has made progress in verifying a POC tool as well as develop new image processing technology. From these verifications, the development has moved on to the feasibility study of inspecting EUV mask pattern defects with D2D and D2DB for the 5nm node and beyond. In this paper, we will present our technology for EUV mask inspection as well as our latest results.","PeriodicalId":138407,"journal":{"name":"Photomask Japan","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124878486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}