L. Verstraete, H. Suh, Julie Van Bel, Purnota Hannan Timi, Rémi Vallat, P. Bézard, J. Vandereyken, Matteo Beggiato, A. Tamaddon, C. Beral, Waikin Li, Mihir Gupta, R. Fallica
Owing to photon shot noise and inhomogeneous distribution of the molecular components in a chemically amplified resist, resist patterns defined by extreme ultraviolet (EUV) lithography tend to suffer from stochastic variations. These stochastic variations are becoming more severe as critical dimensions continue to scale down, and can thus be expected to be a major challenge for the future use of single exposure EUV lithography. Complementing EUV lithography with directed self-assembly (DSA) of block-copolymers provides an interesting opportunity to mitigate the variability related to EUV stochastics. In this work, the DSA rectification process at imec is described for both line/space (L/S) and hexagonal contact hole (HEXCH) patterns. The benefits that rectification can bring, as well as the challenges for further improvement are being addressed based on the current status of imec’s rectification process.
{"title":"Mitigating stochastics in EUV lithography by directed self-assembly","authors":"L. Verstraete, H. Suh, Julie Van Bel, Purnota Hannan Timi, Rémi Vallat, P. Bézard, J. Vandereyken, Matteo Beggiato, A. Tamaddon, C. Beral, Waikin Li, Mihir Gupta, R. Fallica","doi":"10.1117/12.2657939","DOIUrl":"https://doi.org/10.1117/12.2657939","url":null,"abstract":"Owing to photon shot noise and inhomogeneous distribution of the molecular components in a chemically amplified resist, resist patterns defined by extreme ultraviolet (EUV) lithography tend to suffer from stochastic variations. These stochastic variations are becoming more severe as critical dimensions continue to scale down, and can thus be expected to be a major challenge for the future use of single exposure EUV lithography. Complementing EUV lithography with directed self-assembly (DSA) of block-copolymers provides an interesting opportunity to mitigate the variability related to EUV stochastics. In this work, the DSA rectification process at imec is described for both line/space (L/S) and hexagonal contact hole (HEXCH) patterns. The benefits that rectification can bring, as well as the challenges for further improvement are being addressed based on the current status of imec’s rectification process.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123253646","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}
Modelling the pattern formation process in photoresist materials for extreme ultraviolet (EUV) lithography in a stochastic and mechanistic manner, with molecular-scale resolution, should enable predicting the effect of variations of material parameters and process conditions, leading to insights into the ultimate resolution limits. In this work, we present the results of the first steps toward that goal. We describe the physics of the development with time of cascades of electrons and holes, created by the stochastic absorption of 92 eV photons, using a kinetic Monte Carlo model with molecular resolution. The thin film material is modelled assuming a cubic array of lattice sites, at a distance that is consistent with the molecular density of the photoresist material that is considered. The simulation of the cascading process is based on the experimental optical energy loss function, extended to include also excitations with momentum transfer. The method allows for including the Coulomb interactions between charges. In contrast to earlier work, within which the high-energy electrons move ballistically until scattering takes place, the trajectories are in our model formed by stochastically determined interconnected molecular sites. In future extensions of the model, this approach will facilitate including in a natural way a transition from delocalized electron transport at high energies to hopping transport of localized electrons at low energies. The simulations are used to study the sensitivity of the average number of degradations per absorbed photon and the average electron blur length on the rates of elastic scattering and of molecular degradation, and on the energy that is lost upon a molecular degradation process.
{"title":"Towards molecular-scale kinetic Monte Carlo simulation of pattern formation in photoresist materials for EUV nanolithography","authors":"Lois Fernandez Miguez, P. Bobbert, R. Coehoorn","doi":"10.1117/12.2658404","DOIUrl":"https://doi.org/10.1117/12.2658404","url":null,"abstract":"Modelling the pattern formation process in photoresist materials for extreme ultraviolet (EUV) lithography in a stochastic and mechanistic manner, with molecular-scale resolution, should enable predicting the effect of variations of material parameters and process conditions, leading to insights into the ultimate resolution limits. In this work, we present the results of the first steps toward that goal. We describe the physics of the development with time of cascades of electrons and holes, created by the stochastic absorption of 92 eV photons, using a kinetic Monte Carlo model with molecular resolution. The thin film material is modelled assuming a cubic array of lattice sites, at a distance that is consistent with the molecular density of the photoresist material that is considered. The simulation of the cascading process is based on the experimental optical energy loss function, extended to include also excitations with momentum transfer. The method allows for including the Coulomb interactions between charges. In contrast to earlier work, within which the high-energy electrons move ballistically until scattering takes place, the trajectories are in our model formed by stochastically determined interconnected molecular sites. In future extensions of the model, this approach will facilitate including in a natural way a transition from delocalized electron transport at high energies to hopping transport of localized electrons at low energies. The simulations are used to study the sensitivity of the average number of degradations per absorbed photon and the average electron blur length on the rates of elastic scattering and of molecular degradation, and on the energy that is lost upon a molecular degradation process.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124209138","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}
The manufacturing process of advanced logic devices has become ever more challenging than before due to continued shrinkage in dimensions from scaling down and increased complexity from the integration of new transistor structures such as gate-all-around (GAA). Underlayers are utilized as a mask to protect targeted device structures while selected areas of deposited metal is removed by wet etchant during replacement metal gate (RMG) process to construct the transistor. Reported studies describing the developmental strategies for such underlayers have been mostly focused on how to strengthen the adhesion towards the substrate with the designed film properties. In this paper, we identify the effect of plasma during dry etching of the RMG process as the factor to be considered in designing of the wet etch resistant underlayer. Physical and chemical properties of organic films after dry etching with plasmas of different gases have been investigated using various analysis techniques, and the subsequent effect of plasma-modification on the film properties such as resistance towards wet chemicals for various films was evaluated.
{"title":"Modification of organic underlayers by plasma during dry etching and its effect on the film properties","authors":"Soojung Leem, Jae Hwan Sim, Youngeun Bae","doi":"10.1117/12.2658118","DOIUrl":"https://doi.org/10.1117/12.2658118","url":null,"abstract":"The manufacturing process of advanced logic devices has become ever more challenging than before due to continued shrinkage in dimensions from scaling down and increased complexity from the integration of new transistor structures such as gate-all-around (GAA). Underlayers are utilized as a mask to protect targeted device structures while selected areas of deposited metal is removed by wet etchant during replacement metal gate (RMG) process to construct the transistor. Reported studies describing the developmental strategies for such underlayers have been mostly focused on how to strengthen the adhesion towards the substrate with the designed film properties. In this paper, we identify the effect of plasma during dry etching of the RMG process as the factor to be considered in designing of the wet etch resistant underlayer. Physical and chemical properties of organic films after dry etching with plasmas of different gases have been investigated using various analysis techniques, and the subsequent effect of plasma-modification on the film properties such as resistance towards wet chemicals for various films was evaluated.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125429642","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}
S. Lewis, Hayden R. Alty, M. Vockenhuber, G. DeRose, D. Kazazis, G. Timco, James A. Mann, Paul L. Winpenny, A. Scherer, Y. Ekinci, R. Winpenny
In this paper, we report on a novel metal organic photoresist based on heterometallic rings that was designed for electron beam and extreme ultraviolet lithography. From initial electron beam lithography studies, the resist performance demonstrated excellent resolution of 15 nm half-pitch (HP) and a silicon dry etch selectivity of 100:1 but at the expense of sensitivity. To improve sensitivity, a 3D Monte Carlo simulation was employed that utilizes a secondary electron generation model. The simulation suggested that the sensitivity could be dramatically improved while maintaining high resolution by incorporating HgCl2 species into the resist molecular design. This considerably improved the resist sensitivity without losing the high resolution, where it was determined that the resist sensitivity was increased by a factor of 1.6 and 1.94 while demonstrating a resolution of 15 nm and 16 nm HP when exposed with electrons and EUV radiation respectively. Using x-ray photoelectron spectroscopy measurements, we show that after exposure to the electron beam the resist materials are transformed into a metal oxyfluoride and this is why the resist demonstrates high resistance to silicon dry etch conditions achieving a selectivity of 60:1 at a resolution of 15 nm HP.
{"title":"Enhancing the sensitivity of a high resolution negative-tone metal organic photoresist for extreme ultra violet lithography","authors":"S. Lewis, Hayden R. Alty, M. Vockenhuber, G. DeRose, D. Kazazis, G. Timco, James A. Mann, Paul L. Winpenny, A. Scherer, Y. Ekinci, R. Winpenny","doi":"10.1117/12.2658324","DOIUrl":"https://doi.org/10.1117/12.2658324","url":null,"abstract":"In this paper, we report on a novel metal organic photoresist based on heterometallic rings that was designed for electron beam and extreme ultraviolet lithography. From initial electron beam lithography studies, the resist performance demonstrated excellent resolution of 15 nm half-pitch (HP) and a silicon dry etch selectivity of 100:1 but at the expense of sensitivity. To improve sensitivity, a 3D Monte Carlo simulation was employed that utilizes a secondary electron generation model. The simulation suggested that the sensitivity could be dramatically improved while maintaining high resolution by incorporating HgCl2 species into the resist molecular design. This considerably improved the resist sensitivity without losing the high resolution, where it was determined that the resist sensitivity was increased by a factor of 1.6 and 1.94 while demonstrating a resolution of 15 nm and 16 nm HP when exposed with electrons and EUV radiation respectively. Using x-ray photoelectron spectroscopy measurements, we show that after exposure to the electron beam the resist materials are transformed into a metal oxyfluoride and this is why the resist demonstrates high resistance to silicon dry etch conditions achieving a selectivity of 60:1 at a resolution of 15 nm HP.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128908053","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}
R. Fallica, N. Mahne, T. Conard, A. Vanleenhove, S. Nannarone
The blur caused by the nonzero mean free path of electrons in photoresist during extreme ultraviolet lithography has detrimental consequence on patterning resolution, but its effect is difficult to measure experimentally. In this work, a modified substrate-overlayer technique was used to evaluate the attenuation of the photoemission spectra produced in thin chemically amplified photoresist films. The inelastic mean free path of electrons was found to be between 1 to 2 nm in the entire range of interest for EUV lithography (20 to 100 eV kinetic energy). At higher kinetic energy, the mean free path increased consistently with well-known behavior. The presence of photoacid generator and quencher did not change the mean free path significantly (within experimental error).
{"title":"Mean free path of electrons in EUV photoresist in the energy range 20 to 450 eV","authors":"R. Fallica, N. Mahne, T. Conard, A. Vanleenhove, S. Nannarone","doi":"10.1117/12.2658310","DOIUrl":"https://doi.org/10.1117/12.2658310","url":null,"abstract":"The blur caused by the nonzero mean free path of electrons in photoresist during extreme ultraviolet lithography has detrimental consequence on patterning resolution, but its effect is difficult to measure experimentally. In this work, a modified substrate-overlayer technique was used to evaluate the attenuation of the photoemission spectra produced in thin chemically amplified photoresist films. The inelastic mean free path of electrons was found to be between 1 to 2 nm in the entire range of interest for EUV lithography (20 to 100 eV kinetic energy). At higher kinetic energy, the mean free path increased consistently with well-known behavior. The presence of photoacid generator and quencher did not change the mean free path significantly (within experimental error).","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129558635","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}
A single-component silsesquioxane (SQ)-based material was developed and investigated for patterning in extreme ultraviolet (EUV) lithography. This negative-tone SQ-material is soluble in the industry standard aqueous alkali developer 2.38wt% tetramethylammonium hydroxide (TMAH). Early experiments using electron beam (EB) lithography showed pattern capability in resolving 18nm line patterns (exposure dose: 2000 μC/cm2). After numerous screening evaluations using EB lithography, one variant was selected for patterning evaluation with EUV lithography. Patterning resolution was confirmed at 19nm line patterns (exposure dose: 200 mJ/cm2), with evidence of pattern modulation down to 15nm. As revealed in these preliminary patterning investigations, low sensitivity is the obvious issue. To understand the reaction mechanisms of this SQ-based material, various analyses were also carried out. Results reveal the occurrence of direct photo-crosslinking (no main scission) of Si-O-Si bonds from the decomposition of Si-OH components on exposure, resulting in insolubility in the developer solution (negative tone). Lastly, to address the sensitivity issue, the application of what we refer to as “Sensitivity Enhancer Unit” was utilized. EB lithography results show an improvement in sensitivity indicating a possible solution to the low sensitivity issue. These results show the potential applicability of the single-component SQ-based patterning material for both EUV and EB lithography.
{"title":"Single-component silicon-based patterning materials for EUV lithography","authors":"J. Santillan, A. Konda, M. Shichiri, T. Itani","doi":"10.1117/12.2657889","DOIUrl":"https://doi.org/10.1117/12.2657889","url":null,"abstract":"A single-component silsesquioxane (SQ)-based material was developed and investigated for patterning in extreme ultraviolet (EUV) lithography. This negative-tone SQ-material is soluble in the industry standard aqueous alkali developer 2.38wt% tetramethylammonium hydroxide (TMAH). Early experiments using electron beam (EB) lithography showed pattern capability in resolving 18nm line patterns (exposure dose: 2000 μC/cm2). After numerous screening evaluations using EB lithography, one variant was selected for patterning evaluation with EUV lithography. Patterning resolution was confirmed at 19nm line patterns (exposure dose: 200 mJ/cm2), with evidence of pattern modulation down to 15nm. As revealed in these preliminary patterning investigations, low sensitivity is the obvious issue. To understand the reaction mechanisms of this SQ-based material, various analyses were also carried out. Results reveal the occurrence of direct photo-crosslinking (no main scission) of Si-O-Si bonds from the decomposition of Si-OH components on exposure, resulting in insolubility in the developer solution (negative tone). Lastly, to address the sensitivity issue, the application of what we refer to as “Sensitivity Enhancer Unit” was utilized. EB lithography results show an improvement in sensitivity indicating a possible solution to the low sensitivity issue. These results show the potential applicability of the single-component SQ-based patterning material for both EUV and EB lithography.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121022636","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}
Wataru Shibayama, Shuhei Shigaki, S. Takeda, Kodai Kato, M. Nakajima, Rikimaru Sakamoto
For EUV high NA lithography, current conventional tri-layer procss has the critical issue both for EUV litho performance & pattern etch transfer. Especially since the latest EUV PR including CAR and MOR is very low film thickness around 10nm, Si containing hard mask (Si-HM) should be around 5nm. In this case, it is too difficult to transfer to SOC and the bottom hard mask layer. In order to prevent this critical issue, we proose new functional surface treatment process and primers (FSTP) on the conventional CVD hard mask or Si-HM. This FSTP is spin coating materials. However it is almost sigle molecular type ultra thin primer (~1nm) for all of the CVD & spin on hard mask (SiON, SiN, TiN, SiO2, SiHM, SOG and so on) not to bother fine pitch pattern transfer. Moreover, this FSTP has high universalithy to EUV PR CAR and MOR to achieve high patterning performance in EUVL. Therefore FSTP has big advantage in EUV litho process and pattern etch transfer for next generation High NA EUV process.
对于EUV高NA光刻，目前传统的三层工艺在EUV光刻性能和图案蚀刻转移方面存在关键问题。特别是由于最新的EUV PR(包括CAR和MOR)的膜厚度非常低，约为10nm，含硅硬掩膜(Si- hm)应在5nm左右。在这种情况下，很难转移到SOC和底层硬掩膜层。为了防止这一关键问题，我们在传统的CVD硬掩膜或Si-HM上提出了新的功能表面处理工艺和底漆(FSTP)。这种FSTP是旋转涂层材料。然而，它几乎是单分子型超薄底漆(~1nm)，适用于所有硬掩膜(SiON, SiN, TiN, SiO2, SiHM, SOG等)上的CVD和自旋，不会影响精细间距图案转移。此外，该FSTP对EUV、PR、CAR和MOR具有较高的通用性，可在EUVL中实现较高的图形化性能。因此，FSTP在EUV光刻工艺和下一代高NA EUV工艺的图案蚀刻转移方面具有很大的优势。
{"title":"New functional surface treatment process and primers for high-NA EUV lithography","authors":"Wataru Shibayama, Shuhei Shigaki, S. Takeda, Kodai Kato, M. Nakajima, Rikimaru Sakamoto","doi":"10.1117/12.2659979","DOIUrl":"https://doi.org/10.1117/12.2659979","url":null,"abstract":"For EUV high NA lithography, current conventional tri-layer procss has the critical issue both for EUV litho performance & pattern etch transfer. Especially since the latest EUV PR including CAR and MOR is very low film thickness around 10nm, Si containing hard mask (Si-HM) should be around 5nm. In this case, it is too difficult to transfer to SOC and the bottom hard mask layer. In order to prevent this critical issue, we proose new functional surface treatment process and primers (FSTP) on the conventional CVD hard mask or Si-HM. This FSTP is spin coating materials. However it is almost sigle molecular type ultra thin primer (~1nm) for all of the CVD & spin on hard mask (SiON, SiN, TiN, SiO2, SiHM, SOG and so on) not to bother fine pitch pattern transfer. Moreover, this FSTP has high universalithy to EUV PR CAR and MOR to achieve high patterning performance in EUVL. Therefore FSTP has big advantage in EUV litho process and pattern etch transfer for next generation High NA EUV process.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134059798","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}
As lithographic techniques advance in their capabilities of shrinking microelectronics devices, the need for improved resist materials, especially for extreme ultraviolet (EUV), has become increasingly pressing. In this work, we study the molecular layer deposition (MLD) of an Al-based hybrid thin film resist, known as “alucone,” extending our previous research that tested the Hf-based hybrid thin film “hafnicone” as an EUV resist. Alucone is grown at 100 ºC using the metal precursor trimethylaluminum and the organic precursor ethylene glycol. Like hafnicone, alucone behaves as a negative tone resist that can resolve 50-nm line widths, though preliminary data suggest that alucone’s line patterns are more sharply defined than those of hafnicone. Whereas hafnicone’s sensitivity is 400 μC/cm2 using 3 M HCl as the developer, alucone’s sensitivity is not yet as good (4800 μC/cm2 using 0.125 M HCl). Our study of alucone offers new insight into structural features of an MLD film that can lead to desired EUV-responsive behavior. This insight may accelerate the development of vapor-deposited inorganic resists for use in electron-beam and EUV lithography.
随着光刻技术在缩小微电子器件能力方面的进步，对改进的抗蚀剂材料的需求，特别是对极紫外(EUV)的需求，变得越来越迫切。在这项工作中，我们研究了al基杂化薄膜抗蚀剂(称为“alucone”)的分子层沉积(MLD)，扩展了我们之前测试hf基杂化薄膜“hafnicone”作为EUV抗蚀剂的研究。铝酮是用金属前体三甲基铝和有机前体乙二醇在100℃下生长的。与hafnicone一样，alucone的行为是一种负色调抗蚀剂，可以分辨50纳米的线宽，尽管初步数据表明alucone的线模式比hafnicone的线模式更清晰。以3 M HCl为显影剂时，hafnicone的灵敏度为400 μC/cm2，而alucone的灵敏度为4800 μC/cm2 (0.125 M HCl)。我们对铝酮的研究为MLD薄膜的结构特征提供了新的见解，可以导致期望的euv响应行为。这一发现可能会加速用于电子束和EUV光刻的气相沉积无机抗蚀剂的发展。
{"title":"Molecular layer deposition of an Al-based hybrid resist for electron-beam and EUV lithography","authors":"A. Ravi, Jingwei Shi, Jacqueline Lewis, S. Bent","doi":"10.1117/12.2657636","DOIUrl":"https://doi.org/10.1117/12.2657636","url":null,"abstract":"As lithographic techniques advance in their capabilities of shrinking microelectronics devices, the need for improved resist materials, especially for extreme ultraviolet (EUV), has become increasingly pressing. In this work, we study the molecular layer deposition (MLD) of an Al-based hybrid thin film resist, known as “alucone,” extending our previous research that tested the Hf-based hybrid thin film “hafnicone” as an EUV resist. Alucone is grown at 100 ºC using the metal precursor trimethylaluminum and the organic precursor ethylene glycol. Like hafnicone, alucone behaves as a negative tone resist that can resolve 50-nm line widths, though preliminary data suggest that alucone’s line patterns are more sharply defined than those of hafnicone. Whereas hafnicone’s sensitivity is 400 μC/cm2 using 3 M HCl as the developer, alucone’s sensitivity is not yet as good (4800 μC/cm2 using 0.125 M HCl). Our study of alucone offers new insight into structural features of an MLD film that can lead to desired EUV-responsive behavior. This insight may accelerate the development of vapor-deposited inorganic resists for use in electron-beam and EUV lithography.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122434245","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}
Ryo Yokoyama, Akihito Ui, Christi A. Dawydiak, Vinay Kalyani
High resolution, line edge roughness, and sensitivity are the key performance factors to accelerate EUV lithography into high volume manufacturing. EUV is still a developing technology with several intriguing components, such as high NA exposure system and metal oxide resist [1,2]. In terms of cleanliness, the photoresist (PR) and Spin-on carbons (SOC) in underlayers need to have the same level of cleanliness from defect sources to meet the yield targets in the successive photolithography process after exposure. Filtration technology to remove defect sources from raw materials are continuously evolving to adapt to unique behaviors and compatibility of EUV materials. UPE (ultrahigh molecular weight polyethylene) filtration is a critical technology to remove small particles consistently. In this study, UPE filter development is examined to meet the needs of EUV materials. The filter performance was evaluated with underlayer materials. A new design of UPE membrane morphology achieved significant improvements. The details of the extensive experimental result are discussed in the report.
{"title":"Novel UPE filtration technology for advanced photolithography materials","authors":"Ryo Yokoyama, Akihito Ui, Christi A. Dawydiak, Vinay Kalyani","doi":"10.1117/12.2657483","DOIUrl":"https://doi.org/10.1117/12.2657483","url":null,"abstract":"High resolution, line edge roughness, and sensitivity are the key performance factors to accelerate EUV lithography into high volume manufacturing. EUV is still a developing technology with several intriguing components, such as high NA exposure system and metal oxide resist [1,2]. In terms of cleanliness, the photoresist (PR) and Spin-on carbons (SOC) in underlayers need to have the same level of cleanliness from defect sources to meet the yield targets in the successive photolithography process after exposure. Filtration technology to remove defect sources from raw materials are continuously evolving to adapt to unique behaviors and compatibility of EUV materials. UPE (ultrahigh molecular weight polyethylene) filtration is a critical technology to remove small particles consistently. In this study, UPE filter development is examined to meet the needs of EUV materials. The filter performance was evaluated with underlayer materials. A new design of UPE membrane morphology achieved significant improvements. The details of the extensive experimental result are discussed in the report.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"12498 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128912560","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}
C. Dinh, S. Nagahara, Yuhei Kuwahara, Arnaud Dauendorffer, Soichiro Okada, S. Fujimoto, S. Kawakami, S. Shimura, M. Muramatsu, Kayoko Cho, Xiang Liu, K. Nafus, M. Carcasi, Ankur Agarwal, M. Somervell, L. Huli, Kanzo Kato, M. Kocsis, P. de Schepper, S. Meyers, Lauren McQuade, K. Kasahara, J. Garcia Santaclara, R. Hoefnagels, C. Anderson, P. Naulleau
One of the key steps in the pattern formation chain of (extreme ultraviolet) EUV lithography is the development process to resolve the resist pattern after EUV exposure. A simple traditional development process might not be sufficient to achieve the requirements of an ultra-high-resolution feature with low defect levels in high numerical aperture (NA) EUV lithography. In our previous literature, a new development method named ESPERTTM (Enhanced Sensitivity develoPER TechnologyTM) has been introduced to improve the performance of metal oxide resists (MOR) for 0.33 NA EUV lithography by breaking the dose-roughness trade-off. In this work, this development technique was optimised for high-NA lithography to not only keep the advantages of previous ESPERTTM version, but also reduce the defect levels at a higher EUV sensitivity. This is made possible thanks to the capability of the new version of ESPERTTM that can easily remove the residue (undeveloped resist) at low exposure dose area to enhance the developing contrast. Using 0.33 NA EUV scanners at imec on 16-nm half-pitch (HP) line/space (L/S) patterns, with the new development method, EUV dose-to-size (DtS) was reduced roughly 16%, and total after-development-inspection (ADI) defects was reduced by a factor of approximately 7, simultaneously. In another condition, DtS was reduced from 44.2 to 28.4 mJ/cm² (an improvement of 36%), while the number of after-etch-inspection (AEI) single-bridge defects was reduced by half, simultaneously. Using the 0.5 NA exposure tool at Lawrence Berkeley National Laboratory with this new development method, the exposure sensitivity and line-width-roughness (LWR) were both improved by 30% and 21%, respectively. An 8-nm-HP L/S pattern was also successfully printed by this high NA tool. Using a 150 kV electron-beam (EB) lithography system, a 12-nm-HP of pillars was successfully printed on a 22-nm-thick MOR resist with ESPERTTM. With all the advantages of having a high exposure sensitivity, a low defectivity, and an ultra-high-resolution capability, this new development method is expected to be a solution for high-NA EUV lithography.
(极紫外)极紫外光刻成图链的关键步骤之一是极紫外光曝光后抗蚀剂图案的显影过程。在高数值孔径(NA) EUV光刻中，简单的传统开发工艺可能不足以实现低缺陷水平的超高分辨率特征。在我们之前的文献中，已经引入了一种名为ESPERTTM(增强灵敏度显影技术)的新开发方法，通过打破剂量-粗糙度权衡来提高0.33 NA EUV光刻的金属氧化物抗蚀剂(MOR)的性能。在这项工作中，该开发技术针对高na光刻进行了优化，不仅保留了先前ESPERTTM版本的优点，而且在更高的EUV灵敏度下降低了缺陷水平。这是由于新版本的ESPERTTM的能力，可以很容易地去除残留(未显影抗蚀剂)在低暴露剂量区域，以增强显影对比度。在16纳米半间距(HP)线/空间(L/S)模式上使用0.33 NA EUV扫描仪，采用新的开发方法，EUV剂量尺寸比(DtS)减少了约16%，同时开发后检查(ADI)总缺陷减少了约7倍。在另一种条件下，DtS从44.2 mJ/cm²降低到28.4 mJ/cm²(提高了36%)，同时蚀刻后检测(AEI)单桥缺陷数量减少了一半。在美国劳伦斯伯克利国家实验室的0.5 NA曝光工具上使用该方法，曝光灵敏度和线宽粗糙度(LWR)分别提高了30%和21%。该工具还成功打印出了8 nm- hp的L/S图案。利用150 kV电子束(EB)光刻系统，利用ESPERTTM在22 nm厚的MOR抗蚀剂上成功打印了12 nm- hp的柱。这种新的开发方法具有高曝光灵敏度、低缺陷和超高分辨率的优点，有望成为高na EUV光刻的解决方案。
{"title":"Advanced development methods for high-NA EUV lithography","authors":"C. Dinh, S. Nagahara, Yuhei Kuwahara, Arnaud Dauendorffer, Soichiro Okada, S. Fujimoto, S. Kawakami, S. Shimura, M. Muramatsu, Kayoko Cho, Xiang Liu, K. Nafus, M. Carcasi, Ankur Agarwal, M. Somervell, L. Huli, Kanzo Kato, M. Kocsis, P. de Schepper, S. Meyers, Lauren McQuade, K. Kasahara, J. Garcia Santaclara, R. Hoefnagels, C. Anderson, P. Naulleau","doi":"10.1117/12.2655928","DOIUrl":"https://doi.org/10.1117/12.2655928","url":null,"abstract":"One of the key steps in the pattern formation chain of (extreme ultraviolet) EUV lithography is the development process to resolve the resist pattern after EUV exposure. A simple traditional development process might not be sufficient to achieve the requirements of an ultra-high-resolution feature with low defect levels in high numerical aperture (NA) EUV lithography. In our previous literature, a new development method named ESPERTTM (Enhanced Sensitivity develoPER TechnologyTM) has been introduced to improve the performance of metal oxide resists (MOR) for 0.33 NA EUV lithography by breaking the dose-roughness trade-off. In this work, this development technique was optimised for high-NA lithography to not only keep the advantages of previous ESPERTTM version, but also reduce the defect levels at a higher EUV sensitivity. This is made possible thanks to the capability of the new version of ESPERTTM that can easily remove the residue (undeveloped resist) at low exposure dose area to enhance the developing contrast. Using 0.33 NA EUV scanners at imec on 16-nm half-pitch (HP) line/space (L/S) patterns, with the new development method, EUV dose-to-size (DtS) was reduced roughly 16%, and total after-development-inspection (ADI) defects was reduced by a factor of approximately 7, simultaneously. In another condition, DtS was reduced from 44.2 to 28.4 mJ/cm² (an improvement of 36%), while the number of after-etch-inspection (AEI) single-bridge defects was reduced by half, simultaneously. Using the 0.5 NA exposure tool at Lawrence Berkeley National Laboratory with this new development method, the exposure sensitivity and line-width-roughness (LWR) were both improved by 30% and 21%, respectively. An 8-nm-HP L/S pattern was also successfully printed by this high NA tool. Using a 150 kV electron-beam (EB) lithography system, a 12-nm-HP of pillars was successfully printed on a 22-nm-thick MOR resist with ESPERTTM. With all the advantages of having a high exposure sensitivity, a low defectivity, and an ultra-high-resolution capability, this new development method is expected to be a solution for high-NA EUV lithography.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128507893","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}
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