F. Käfer, Z. MEng, R. Segalman, Javier Read de Alaniz, C. Ober
One of the major challenges to lithography today is minimizing the consequences of stochastics, that is, the effect of statistical differences in photoresist structure and the distribution of additives, such as photo active compounds, in the photoresist. Most polymer photoresists due to their method of production will have large differences between polymer chains in molecular weight, composition, and sequence due to the nature of polymer synthesis. However, there exist methods of polymer formation that make uniform composition polymers such a homopolymers made using living polymerization. We discuss scissionable poly(phthalaldehyde)s as one example of a low stochastics photoresist. Using another method originally developed for the biological community we make polymers in which molecular weight, composition and sequence are identical in all polymer chains produced. Here we thus describe studies of polypeptoids, synthetic analogs of peptides, which have no chirality and in which the substituents are placed on the backbone nitrogen. The peptoids are produced as chemically amplified photoresists and are intended for study as EUV materials. To produce a CAR with aqueous base development using this hydrophilic backbone we have successfully learned how to make a more hydrophobic patterning system with Tg >100 °C. With our ability to control of sequence we have started to explore the effect that monomer placement has on lithographic performance and found that indeed sequence does play an important role. Sequences of solubility switch groups, adhesive, etch resistant and hydrophobic groups have been studied. Using e-beam lithography we have recently demonstrated sub-30 nm resolution.
{"title":"Photoresists with precisely controlled molecular weight, composition, and sequence","authors":"F. Käfer, Z. MEng, R. Segalman, Javier Read de Alaniz, C. Ober","doi":"10.1117/12.2658582","DOIUrl":"https://doi.org/10.1117/12.2658582","url":null,"abstract":"One of the major challenges to lithography today is minimizing the consequences of stochastics, that is, the effect of statistical differences in photoresist structure and the distribution of additives, such as photo active compounds, in the photoresist. Most polymer photoresists due to their method of production will have large differences between polymer chains in molecular weight, composition, and sequence due to the nature of polymer synthesis. However, there exist methods of polymer formation that make uniform composition polymers such a homopolymers made using living polymerization. We discuss scissionable poly(phthalaldehyde)s as one example of a low stochastics photoresist. Using another method originally developed for the biological community we make polymers in which molecular weight, composition and sequence are identical in all polymer chains produced. Here we thus describe studies of polypeptoids, synthetic analogs of peptides, which have no chirality and in which the substituents are placed on the backbone nitrogen. The peptoids are produced as chemically amplified photoresists and are intended for study as EUV materials. To produce a CAR with aqueous base development using this hydrophilic backbone we have successfully learned how to make a more hydrophobic patterning system with Tg >100 °C. With our ability to control of sequence we have started to explore the effect that monomer placement has on lithographic performance and found that indeed sequence does play an important role. Sequences of solubility switch groups, adhesive, etch resistant and hydrophobic groups have been studied. Using e-beam lithography we have recently demonstrated sub-30 nm resolution.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"30 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":"133251058","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}
K. Macwilliams, A. Ceballos, Ted Prescop, D. K. Lam
Multibeam Corporation has overcome the productivity limitations of conventional single-electron-beam lithography to enable high-speed, flexible, and high-resolution patterning in a range of new and existing applications. The high-productivity Multicolumn Electron Beam Lithography (MEBL) system combines a modular architecture with unique miniature e-beam columns to achieve productivity that is taking e-beam lithography from lab to fab. MEBL exhibits 10 to 100x productivity in most applications compared to conventional e-beam lithography. Beyond its superior resolution, MEBL also offers several important advantages over conventional photolithography: (1) Depth of Focus – over 100x larger than state-of-the-art optical systems. (2) Full-wafer Writing Field – the ability to write unique, seamless patterns over an entire wafer, not limited by conventional optical reticle size (typically 26 mm x 33 mm). (3) Perhaps most powerfully – direct writing is maskless. E-beam lithography is adaptable and is not constrained by the time, cost, defectivity, and security risks of the optical mask production process. The design and manufacturing capabilities that emerge from combining high-productivity with these unique e-beam lithography capabilities enable many key applications: super-large interposers for microelectronics advanced packaging (that can achieve size, weight, power, and performance close to that of wafer-scale integration); seamless patterning of readout integrated circuits (ROICs) and other larger-area devices; built-in Secure Chip IDs that ensure security and chip-level traceability; and high-mix, low-volume production (to leverage high-volume IC technology for low-volume applications). The adaptable, direct-write nature of e-beam lithography also enables early concept prototyping that accelerates technology development, production ramp-up, and system deployments. These advanced capabilities are shown using Multibeam’s high-productivity, direct-write MEBL system.
Multibeam公司克服了传统单电子束光刻的生产效率限制，在一系列新的和现有的应用中实现了高速、灵活和高分辨率的图形。高生产率的多柱电子束光刻(MEBL)系统结合了模块化架构和独特的微型电子束柱，以实现从实验室到工厂的电子束光刻的生产率。与传统电子束光刻相比，MEBL在大多数应用中表现出10到100倍的生产率。除了其优越的分辨率，MEBL还提供了几个重要的优势比传统的光刻:(1)聚焦深度-超过100倍的最先进的光学系统。(2)全晶圆书写领域-在整个晶圆上书写独特，无缝图案的能力，不受传统光学光栅尺寸(通常为26 mm x 33 mm)的限制。(3)也许最有力的是——直接写作是没有面具的。电子束光刻技术适应性强，不受光掩模生产过程的时间、成本、缺陷和安全风险的限制。将高生产率与这些独特的电子束光刻能力相结合所产生的设计和制造能力使许多关键应用成为可能:用于微电子先进封装的超大中间体(可以实现尺寸，重量，功率和性能接近晶圆级集成);读出集成电路(roic)和其他更大面积器件的无缝图像化;内置安全芯片id，确保安全性和芯片级可追溯性;以及高混合、小批量生产(利用大批量集成电路技术实现小批量应用)。电子束光刻具有适应性强、直接写入的特点，能够实现早期概念原型，从而加速技术开发、生产提升和系统部署。这些先进的功能通过Multibeam的高生产率、直写MEBL系统得到了展示。
{"title":"High-productivity direct-write e-beam lithography: an enabling patterning technology to augment your lithography toolbox","authors":"K. Macwilliams, A. Ceballos, Ted Prescop, D. K. Lam","doi":"10.1117/12.2658237","DOIUrl":"https://doi.org/10.1117/12.2658237","url":null,"abstract":"Multibeam Corporation has overcome the productivity limitations of conventional single-electron-beam lithography to enable high-speed, flexible, and high-resolution patterning in a range of new and existing applications. The high-productivity Multicolumn Electron Beam Lithography (MEBL) system combines a modular architecture with unique miniature e-beam columns to achieve productivity that is taking e-beam lithography from lab to fab. MEBL exhibits 10 to 100x productivity in most applications compared to conventional e-beam lithography. Beyond its superior resolution, MEBL also offers several important advantages over conventional photolithography: (1) Depth of Focus – over 100x larger than state-of-the-art optical systems. (2) Full-wafer Writing Field – the ability to write unique, seamless patterns over an entire wafer, not limited by conventional optical reticle size (typically 26 mm x 33 mm). (3) Perhaps most powerfully – direct writing is maskless. E-beam lithography is adaptable and is not constrained by the time, cost, defectivity, and security risks of the optical mask production process. The design and manufacturing capabilities that emerge from combining high-productivity with these unique e-beam lithography capabilities enable many key applications: super-large interposers for microelectronics advanced packaging (that can achieve size, weight, power, and performance close to that of wafer-scale integration); seamless patterning of readout integrated circuits (ROICs) and other larger-area devices; built-in Secure Chip IDs that ensure security and chip-level traceability; and high-mix, low-volume production (to leverage high-volume IC technology for low-volume applications). The adaptable, direct-write nature of e-beam lithography also enables early concept prototyping that accelerates technology development, production ramp-up, and system deployments. These advanced capabilities are shown using Multibeam’s high-productivity, direct-write MEBL system.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"35 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":"126814055","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}
Kazunori Shinoda, Nobuya Miyoshi, Hiroyuki Kobayashi, M. Izawa, K. Ishikawa, M. Hori
There has been considerable interest in the development of isotropic atomic layer etching (ALE) for the conformal removal of thin films. Material selectivity is crucial for the development of isotropic ALE because the next generation of semiconductor devices will be constructed with miniaturized 3D structures using a variety of very thin films. We developed plasma-assisted thermal-cyclic ALE, which is a repetition of surface modification by plasma exposure and removal of the modified surface by infrared heating. We developed a 300-mm tool, namely, dry chemical removal (DCR), which is equipped with an inductively coupled plasma (ICP) source and infrared lamps, to facilitate rapid thermal desorption of the modified surface. An important feature of the plasma-assisted thermal-cyclic ALE is that it has more tuning knobs than that of conventional ALE because it uses two temperatures: a low temperature for surface modification and an elevated temperature for the removal of the modified surface. This paper presents the selective ALE of various materials, i.e., Si3N4, TiN, W, and SiGe using the developed tool. The mechanisms of the selectivity are divided into two categories: formation of an ammonium salt-based modified layer and selectivity control by adjusting the infrared heating time. This paper reviews the selective ALE mechanisms, focusing on the results of in situ analysis of surface reactions, and presents some of the latest findings.
{"title":"Selective isotropic atomic-layer etching of thin films by using dry chemical removal tool","authors":"Kazunori Shinoda, Nobuya Miyoshi, Hiroyuki Kobayashi, M. Izawa, K. Ishikawa, M. Hori","doi":"10.1117/12.2664547","DOIUrl":"https://doi.org/10.1117/12.2664547","url":null,"abstract":"There has been considerable interest in the development of isotropic atomic layer etching (ALE) for the conformal removal of thin films. Material selectivity is crucial for the development of isotropic ALE because the next generation of semiconductor devices will be constructed with miniaturized 3D structures using a variety of very thin films. We developed plasma-assisted thermal-cyclic ALE, which is a repetition of surface modification by plasma exposure and removal of the modified surface by infrared heating. We developed a 300-mm tool, namely, dry chemical removal (DCR), which is equipped with an inductively coupled plasma (ICP) source and infrared lamps, to facilitate rapid thermal desorption of the modified surface. An important feature of the plasma-assisted thermal-cyclic ALE is that it has more tuning knobs than that of conventional ALE because it uses two temperatures: a low temperature for surface modification and an elevated temperature for the removal of the modified surface. This paper presents the selective ALE of various materials, i.e., Si3N4, TiN, W, and SiGe using the developed tool. The mechanisms of the selectivity are divided into two categories: formation of an ammonium salt-based modified layer and selectivity control by adjusting the infrared heating time. This paper reviews the selective ALE mechanisms, focusing on the results of in situ analysis of surface reactions, and presents some of the latest findings.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"32 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":"114476547","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. Nagahara, Arnaud Dauendorffer, A. Thiam, Xiang Liu, Yuhei Kuwahara, C. Dinh, Soichiro Okada, S. Kawakami, H. Genjima, Noriaki Nagamine, M. Muramatsu, S. Shimura, A. Tsuboi, K. Nafus, Y. Feurprier, M. Demand, R. Ramaneti, P. Foubert, D. De Simone, Geert Vendenberghe
High-NA EUV lithography is currently under development to keep up with device node scaling with smaller feature sizes. In this paper, the most recent advances in EUV patterning using metal oxide resists (MOR) and chemically amplified resists (CAR) are discussed. A newly developed resist development method (ESPERT™) was examined on MOR with 24 nm pitch line and space (L/S) patterns and 32 nm pitch pillars for preparation of high-NA EUV patterning. The patterning results showed improved sensitivity and pattern collapse margin. CAR contact hole patterning at 28 nm pitch was also examined by stochastic lithography simulation. The simulation results indicate that resist film thickness needs to be optimized for target pitches.
{"title":"Recent advances in EUV patterning in preparation towards high-NA EUV","authors":"S. Nagahara, Arnaud Dauendorffer, A. Thiam, Xiang Liu, Yuhei Kuwahara, C. Dinh, Soichiro Okada, S. Kawakami, H. Genjima, Noriaki Nagamine, M. Muramatsu, S. Shimura, A. Tsuboi, K. Nafus, Y. Feurprier, M. Demand, R. Ramaneti, P. Foubert, D. De Simone, Geert Vendenberghe","doi":"10.1117/12.2657432","DOIUrl":"https://doi.org/10.1117/12.2657432","url":null,"abstract":"High-NA EUV lithography is currently under development to keep up with device node scaling with smaller feature sizes. In this paper, the most recent advances in EUV patterning using metal oxide resists (MOR) and chemically amplified resists (CAR) are discussed. A newly developed resist development method (ESPERT™) was examined on MOR with 24 nm pitch line and space (L/S) patterns and 32 nm pitch pillars for preparation of high-NA EUV patterning. The patterning results showed improved sensitivity and pattern collapse margin. CAR contact hole patterning at 28 nm pitch was also examined by stochastic lithography simulation. The simulation results indicate that resist film thickness needs to be optimized for target pitches.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"27 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":"129361841","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 improvement of accuracy and efficiency in simulating the profile of the chemically amplified resist (CAR) is always a key point in lithography. With the development of machine learning, many models have been successfully applied in optical proximity correction (OPC), hotspot detection, and other lithographic fields. In this work, we developed a neural network for predicting the critical features’ sizes of the CAR profile. By using a pre-calibrated physical resist model, the effectiveness of this model is demonstrated from numerical simulation. The results indicate that for the critical dimensions (CDs) of the CAR profile, this model shows great speed and accuracy. After applying the tuned neural network on the test sets, it shows 92.98% of the test sets have a mean square error (MSE) less than 1%.
{"title":"Predicting the critical features of the chemically-amplified resist profile based on machine learning","authors":"Pengjie Kong, Lisong Dong, Xu Ma, Yayi Wei","doi":"10.1117/12.2658664","DOIUrl":"https://doi.org/10.1117/12.2658664","url":null,"abstract":"The improvement of accuracy and efficiency in simulating the profile of the chemically amplified resist (CAR) is always a key point in lithography. With the development of machine learning, many models have been successfully applied in optical proximity correction (OPC), hotspot detection, and other lithographic fields. In this work, we developed a neural network for predicting the critical features’ sizes of the CAR profile. By using a pre-calibrated physical resist model, the effectiveness of this model is demonstrated from numerical simulation. The results indicate that for the critical dimensions (CDs) of the CAR profile, this model shows great speed and accuracy. After applying the tuned neural network on the test sets, it shows 92.98% of the test sets have a mean square error (MSE) less than 1%.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"10 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":"114076232","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}
Satoshi Dei, Yuya Hayashi, S. Akita, Shuhei Yamada, K. Sakai, Tatsuya Kasai, Akitaka Nii, Ayaka Furusawa, K. Takada, T. Kaneko, Tomoaki Seko, Eiji Yoneda, Tatsuya Sakai
We introduce thin underlayer (UL) materials (<10 nm) for metal oxide resist (MOR) that can support the lithography performance requirements as well as compatible with conventional etching tool and etching process. Thin UL materials for MOR patterning applications required to have chemical moieties with specific functions and excellent physical properties to meet both lithography and etching performance requirements. We investigated the relationship between surface properties of thin UL materials and its effects on MOR sensitivity, pattern collapse, and defects. We also discussed plausible mechanism based on our experimental results. In addition, we have also confirmed the impact of high EUV absorption unit effect in UL materials on MOR sensitivity.
{"title":"Thin underlayer materials for metal oxide resist patterning","authors":"Satoshi Dei, Yuya Hayashi, S. Akita, Shuhei Yamada, K. Sakai, Tatsuya Kasai, Akitaka Nii, Ayaka Furusawa, K. Takada, T. Kaneko, Tomoaki Seko, Eiji Yoneda, Tatsuya Sakai","doi":"10.1117/12.2657918","DOIUrl":"https://doi.org/10.1117/12.2657918","url":null,"abstract":"We introduce thin underlayer (UL) materials (<10 nm) for metal oxide resist (MOR) that can support the lithography performance requirements as well as compatible with conventional etching tool and etching process. Thin UL materials for MOR patterning applications required to have chemical moieties with specific functions and excellent physical properties to meet both lithography and etching performance requirements. We investigated the relationship between surface properties of thin UL materials and its effects on MOR sensitivity, pattern collapse, and defects. We also discussed plausible mechanism based on our experimental results. In addition, we have also confirmed the impact of high EUV absorption unit effect in UL materials on MOR sensitivity.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"34 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":"116312907","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}
Yuhei Kuwahara, S. Kawakami, Kanzo Kato, Soichiro Okada, Y. Kamei, T. Onitsuka, T. Yamauchi, Nanoka Miyahara, C. Dinh, L. Huli, S. Shimura
Resolution, line edge roughness (LER) and sensitivity (RLS) and defectivity are the well-known critical issues of extreme ultraviolet (EUV) lithography. To break the RLS triangle, metal oxide resist (MOR) is a promising candidate. However, further improvement of MOR process is required for high volume manufacturing to maintain low defectivity. In this paper, conventional and new processes for MOR pitch 32 nm line and space (L/S) and 36 nm pillar patterns was investigated. This new process was able to perform good sensitivity without degrading roughness. In addition, further optimization for underlayer and developer process could mitigate pattern collapses. MOR treatment was evaluated as another technique for roughness improvement. At last, bottom scum defect would be reduced by new process.
{"title":"Establishment of new process technology for EUV lithography","authors":"Yuhei Kuwahara, S. Kawakami, Kanzo Kato, Soichiro Okada, Y. Kamei, T. Onitsuka, T. Yamauchi, Nanoka Miyahara, C. Dinh, L. Huli, S. Shimura","doi":"10.1117/12.2657076","DOIUrl":"https://doi.org/10.1117/12.2657076","url":null,"abstract":"Resolution, line edge roughness (LER) and sensitivity (RLS) and defectivity are the well-known critical issues of extreme ultraviolet (EUV) lithography. To break the RLS triangle, metal oxide resist (MOR) is a promising candidate. However, further improvement of MOR process is required for high volume manufacturing to maintain low defectivity. In this paper, conventional and new processes for MOR pitch 32 nm line and space (L/S) and 36 nm pillar patterns was investigated. This new process was able to perform good sensitivity without degrading roughness. In addition, further optimization for underlayer and developer process could mitigate pattern collapses. MOR treatment was evaluated as another technique for roughness improvement. At last, bottom scum defect would be reduced by new process.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"5 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":"122257823","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}
G. Mannaert, H. Mertens, M. Hosseini, S. Demuynck, V. Nguyen, B. Chan, F. Lazzarino
In a complementary-FET (CFET), n- and p- type transistors are stacked on top of each other. This stacking approach results in very high aspect ratio vertical features which brings critical challenges for nanosheet (NSH), gate, spacer, and source/drain (S/D) cavity patterning. Silicon nitride spacers are commonly used to electrically isolate and protect the silicon gate during S/D epitaxial growth and to precisely define the channel length (Lg) [1-4]. In this work, we will discuss the spacer film opening, the optimization of the S/D cavity profile and propose options to reduce the gate hard mask consumption. We were able to straighten the S/D cavity profile in the SiGe superlattice substrate by tuning specific process parameters, during the various etch and over-etch steps of the stack. Chemical analysis of the sidewall of the cavity, by TEM/EDS, confirmed that the formation of a passivation oxi-nitride compound is key to achieve vertical cavity profile. The chemical mapping of the cavity was done through the Si and SiGe25% sheets. A Si, O and N containing passivation layer is present in the cavity which seems to be thicker at the top and thinner at the bottom of the cavity. Furthermore, polymer capping methods were investigated to reduce the consumption of oxide hard mask (HM) during spacer etch. Process optimization for the cavity shape in the S/D recess etch was conducted using TEM characterization.
{"title":"Challenges for spacer and source/drain cavity patterning in CFET devices","authors":"G. Mannaert, H. Mertens, M. Hosseini, S. Demuynck, V. Nguyen, B. Chan, F. Lazzarino","doi":"10.1117/12.2658073","DOIUrl":"https://doi.org/10.1117/12.2658073","url":null,"abstract":"In a complementary-FET (CFET), n- and p- type transistors are stacked on top of each other. This stacking approach results in very high aspect ratio vertical features which brings critical challenges for nanosheet (NSH), gate, spacer, and source/drain (S/D) cavity patterning. Silicon nitride spacers are commonly used to electrically isolate and protect the silicon gate during S/D epitaxial growth and to precisely define the channel length (Lg) [1-4]. In this work, we will discuss the spacer film opening, the optimization of the S/D cavity profile and propose options to reduce the gate hard mask consumption. We were able to straighten the S/D cavity profile in the SiGe superlattice substrate by tuning specific process parameters, during the various etch and over-etch steps of the stack. Chemical analysis of the sidewall of the cavity, by TEM/EDS, confirmed that the formation of a passivation oxi-nitride compound is key to achieve vertical cavity profile. The chemical mapping of the cavity was done through the Si and SiGe25% sheets. A Si, O and N containing passivation layer is present in the cavity which seems to be thicker at the top and thinner at the bottom of the cavity. Furthermore, polymer capping methods were investigated to reduce the consumption of oxide hard mask (HM) during spacer etch. Process optimization for the cavity shape in the S/D recess etch was conducted using TEM characterization.","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":"128130473","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}
M. Gentile, M. Gerlach, R. Richter, M. V. van Setten, J. Petersen, P. van der Heide, F. Holzmeier
The dissociative photoionization of tert-butyl methyl methacrylate, a monomer unit found in many ESCAP resists, was investigated in a gas phase photoelectron photoion coincidence experiment employing extreme ultraviolet (EUV) synchrotron radiation at 13.5 nm. It was found that the interaction of EUV photons with the molecules leads almost exclusively to dissociation. However, the ionization can also directly deprotect the ester function, thus inducing the solubility switch wanted in a resist film. These results serve as a building block to reconstruct the full picture of the mechanism in widely used chemically amplified resist thin films, provide a knob to tailor more performant resist materials, and will aid interpreting advanced ultrafast time-resolved experiments.
{"title":"Dissociative photoionization of EUV lithography photoresist models","authors":"M. Gentile, M. Gerlach, R. Richter, M. V. van Setten, J. Petersen, P. van der Heide, F. Holzmeier","doi":"10.1117/12.2657702","DOIUrl":"https://doi.org/10.1117/12.2657702","url":null,"abstract":"The dissociative photoionization of tert-butyl methyl methacrylate, a monomer unit found in many ESCAP resists, was investigated in a gas phase photoelectron photoion coincidence experiment employing extreme ultraviolet (EUV) synchrotron radiation at 13.5 nm. It was found that the interaction of EUV photons with the molecules leads almost exclusively to dissociation. However, the ionization can also directly deprotect the ester function, thus inducing the solubility switch wanted in a resist film. These results serve as a building block to reconstruct the full picture of the mechanism in widely used chemically amplified resist thin films, provide a knob to tailor more performant resist materials, and will aid interpreting advanced ultrafast time-resolved experiments.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"28 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":"123673684","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}
Nanoka Miyahara, Soichiro Okada, Hiroyuki Fujii, S. Shimura
Extreme ultraviolet (EUV) lithography has already utilized for high volume manufacturing, and miniaturization by numerical aperture (NA) 0.33 is approaching to the limit. Pitch 24 nm line and space (L/S) resist patterns can be resolved with single exposure at even NA 0.33. However, etch transfer performance to underlayer materials is one of the issues. Especially, in narrow pitch case, it is very difficult to etch due to the lack of resist mask resistance. Therefore, resist pattern thickening process with optimized development process and underlayer state was studied and verified the pattern height impact at our past paper. As a result, it found that combination of the underlayer (UL) kinds and their status was one of the key points to lead high-quality patterns. In this paper, optimized stack structure narrow pitch pattern and lithography performance. As a result, in experiments toward High NA EUV, 24 nm pitch L/S pattern could be patterned (near smallest size by NA 0.33) by selecting the optimal ML/UL combination, and some defect free process windows were kept between defect cliffs.
{"title":"Fundamentals of EUV stack for improving patterning performance","authors":"Nanoka Miyahara, Soichiro Okada, Hiroyuki Fujii, S. Shimura","doi":"10.1117/12.2657056","DOIUrl":"https://doi.org/10.1117/12.2657056","url":null,"abstract":"Extreme ultraviolet (EUV) lithography has already utilized for high volume manufacturing, and miniaturization by numerical aperture (NA) 0.33 is approaching to the limit. Pitch 24 nm line and space (L/S) resist patterns can be resolved with single exposure at even NA 0.33. However, etch transfer performance to underlayer materials is one of the issues. Especially, in narrow pitch case, it is very difficult to etch due to the lack of resist mask resistance. Therefore, resist pattern thickening process with optimized development process and underlayer state was studied and verified the pattern height impact at our past paper. As a result, it found that combination of the underlayer (UL) kinds and their status was one of the key points to lead high-quality patterns. In this paper, optimized stack structure narrow pitch pattern and lithography performance. As a result, in experiments toward High NA EUV, 24 nm pitch L/S pattern could be patterned (near smallest size by NA 0.33) by selecting the optimal ML/UL combination, and some defect free process windows were kept between defect cliffs.","PeriodicalId":212235,"journal":{"name":"Advanced Lithography","volume":"4 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":"127110786","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：