{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T04:27:43Z","timestamp":1787113663165,"version":"build-2736575974"},"reference-count":41,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,15]],"date-time":"2026-08-15T00:00:00Z","timestamp":1786752000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Micromachines"],"abstract":"<jats:p>Hafnium oxide (HfO2) has emerged as a promising charge trap layer (CTL) for nonvolatile memory devices; however, its long-term reliability remains challenging due to leakage current through grain boundary pathways and interface defect formation. Within plasma-enhanced atomic layer deposition (PEALD), direct plasma ALD (DPALD) forms crystalline HfO2 with deeper trap sites, while its ion-assisted nature may contribute to interface damage, resulting in a lower net trap density than remote plasma ALD (RPALD), which better preserves interfacial quality. We propose an interface\u2013bulk\u2013interface (RP\/DP\/RP) process design that places RPALD at the interfaces and DPALD in the bulk, aiming to combine bulk trap sites with interfacial protection. Charge trap memory (CTM) devices were fabricated across RP\/DP\/RP thickness combinations. Within the tested range, the optimized structure exhibited the widest memory window and the highest effective trapped charge density among the measured devices, improving upon DPALD and comparable to RPALD, together with the lowest near-interface trap density at the Si\/Al2O3 interface. The device also maintained a stable memory window up to 104 program\/erase cycles, and short-term retention data suggest potentially stable program and erase states, requiring longer-term validation. These results indicate that spatial modulation of plasma modes offers a process-level strategy for improving HfO2-based CTM devices.<\/jats:p>","DOI":"10.3390\/mi17080965","type":"journal-article","created":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T13:42:17Z","timestamp":1786974137000},"page":"965","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Selective Plasma Mode Modulation in HfO2 Charge Trap Layers via RP\/DP\/RP Atomic Layer Deposition for Enhanced Memory Performance and Interface Quality"],"prefix":"10.3390","volume":"17","author":[{"given":"Byungwook","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Advanced Materials Engineering, Tech University of Korea, Siheung-si 15073, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yongwoon","family":"Jang","sequence":"additional","affiliation":[{"name":"Department of Advanced Materials Engineering, Tech University of Korea, Siheung-si 15073, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hyeonwu","family":"Nam","sequence":"additional","affiliation":[{"name":"Department of Advanced Materials Engineering, Tech University of Korea, Siheung-si 15073, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Changyun","family":"Hong","sequence":"additional","affiliation":[{"name":"Department of Advanced Materials Engineering, Tech University of Korea, Siheung-si 15073, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Minkyun","family":"Kang","sequence":"additional","affiliation":[{"name":"Department of Advanced Materials Engineering, Tech University of Korea, Siheung-si 15073, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wookyung","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Advanced Materials Engineering, Tech University of Korea, Siheung-si 15073, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9640-0804","authenticated-orcid":false,"given":"Changbun","family":"Yoon","sequence":"additional","affiliation":[{"name":"Department of Advanced Materials Engineering, Tech University of Korea, Siheung-si 15073, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2200659","DOI":"10.1002\/adma.202200659","article-title":"Review of semiconductor flash memory devices for material and process issues","volume":"35","author":"Kim","year":"2023","journal-title":"Adv. Mater."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1800914","DOI":"10.1002\/aelm.201800914","article-title":"What will come after V-NAND\u2014Vertical resistive switching memory?","volume":"5","author":"Yoon","year":"2019","journal-title":"Adv. Electron. Mater."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"315301","DOI":"10.1088\/1361-6528\/adf33e","article-title":"Controllable formation of HfO2 thin film in 20 nm thick lateral trenches with high aspect ratio up to 30","volume":"36","author":"Fan","year":"2025","journal-title":"Nanotechnology"},{"key":"ref_4","unstructured":"Kim, J., Hong, A.J., Ogawa, M., Ma, S., Song, E.B., Lin, Y.-S., Han, J., Chung, U.-I., and Wang, K.L. (2008). Novel 3-D structure for ultra-high density flash memory with VRAT (Vertical-Recess-Array-Transistor) and PIPE (Planarized Integration on the same PlanE). 2008 Symposium on VLSI Technology, IEEE."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Spassov, D., Paskaleva, A., Guziewicz, E., Wozniak, W., Stanchev, T., Ivanov, T., Wojewoda-Budka, J., and Janusz-Skuza, M. (2022). Charge storage and reliability characteristics of nonvolatile memory capacitors with HfO2\/Al2O3-based charge trapping layers. Materials, 15.","DOI":"10.3390\/ma15186285"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Yoo, J.-H., Park, W.-J., Kim, S.-W., Lee, G.-R., Kim, J.-H., Lee, J.-H., Uhm, S.-H., and Lee, H.-C. (2023). Preparation of remote plasma atomic layer-deposited HfO2 thin films with high charge trapping densities and their application in nonvolatile memory devices. Nanomaterials, 13.","DOI":"10.3390\/nano13111785"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Zhang, X.-Y., Han, J., Peng, D.-C., Ruan, Y.-J., Wu, W.-Y., Wuu, D.-S., Huang, C.-J., Lien, S.-Y., and Zhu, W.-Z. (2022). Crystallinity effect on electrical properties of PEALD\u2013HfO2 thin films prepared by different substrate temperatures. Nanomaterials, 12.","DOI":"10.3390\/nano12213890"},{"key":"ref_8","first-page":"489","article-title":"Aggressively scaled ultra-thin undoped HfO2 gate dielectric (EOT < 0.7 nm) with TaN gate electrode using engineered interface layer","volume":"26","author":"Choi","year":"2005","journal-title":"IEEE Electron Device Lett."},{"key":"ref_9","unstructured":"Ando, T., Frank, M.M., Choi, K., Choi, C., Bruley, J., Hopstaken, M., Copel, M., Cartier, E., Kerber, A., and Callegari, A. (2009, January 7\u20139). Understanding mobility mechanisms in extremely scaled HfO2 (EOT 0.42 nm) using remote interfacial layer scavenging technique and Vt-tuning dipoles with gate-first process. Proceedings of the 2009 IEEE International Electron Devices Meeting (IEDM), Baltimore, MD, USA."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1016\/j.mee.2012.07.061","article-title":"Application of nanosphere lithography to charge trap flash memories with patterned Si3N4 trap layers","volume":"98","author":"An","year":"2012","journal-title":"Microelectron. Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"115964","DOI":"10.1016\/j.mseb.2022.115964","article-title":"ALD and PEALD deposition of HfO2 and its effects on the nature of oxygen vacancies","volume":"285","author":"Horley","year":"2022","journal-title":"Mater. Sci. Eng. B"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"172902","DOI":"10.1063\/1.4900745","article-title":"Defect states and charge trapping characteristics of HfO2 films for high performance nonvolatile memory applications","volume":"105","author":"Zhang","year":"2014","journal-title":"Appl. Phys. Lett."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"4633","DOI":"10.1021\/acsanm.8b00918","article-title":"Sub-1 nm Equivalent Oxide Thickness Al-HfO2 Trapping Layer with Excellent Thermal Stability and Retention for Nonvolatile Memory","volume":"1","author":"Spiga","year":"2018","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_14","first-page":"545","article-title":"Synthesis and characterization of monodisperse nanocrystals and close-packed nanocrystal assemblies","volume":"30","author":"Murray","year":"2000","journal-title":"Annu. Rev. Mater. Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3450","DOI":"10.1063\/1.1328101","article-title":"Charge storage and interface states effects in Si-nanocrystal memory obtained using low-energy Si+ implantation and annealing","volume":"77","author":"Kapetanakis","year":"2000","journal-title":"Appl. Phys. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"384","DOI":"10.1109\/TED.2002.807447","article-title":"Improvement of surface carrier mobility of HfO2 MOSFETs by high-temperature forming gas annealing","volume":"50","author":"Iwai","year":"2003","journal-title":"IEEE Trans. Electron Devices"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1149\/05013.0023ecst","article-title":"Ion bombardment during plasma-assisted atomic layer deposition","volume":"50","author":"Profijt","year":"2012","journal-title":"ECS Trans."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"040801","DOI":"10.1116\/6.0000145","article-title":"The role of plasma in plasma-enhanced atomic layer deposition of crystalline films","volume":"38","author":"Boris","year":"2020","journal-title":"J. Vac. Sci. Technol. A"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Hwang, I., Nam, H., Kim, J., Kim, B., Jang, Y., Lee, W., Kang, M., and Yoon, C. (2026). Interface-Engineered, Low-Damage IGZO\/HfO2 Charge-Trapping Memory Devices Fabricated Using a Remote Plasma ALD Process. Micromachines, 17.","DOI":"10.3390\/mi17060743"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"28407","DOI":"10.1021\/acsami.9b07090","article-title":"PEALD of HfO2 thin films: Precursor tuning and a new near-ambient-pressure XPS approach to in situ examination of thin-film surfaces exposed to reactive gases","volume":"11","author":"Zanders","year":"2019","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"053108","DOI":"10.1063\/1.2005370","article-title":"Characteristics of HfO2 thin films grown by plasma atomic layer deposition","volume":"87","author":"Kim","year":"2005","journal-title":"Appl. Phys. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"26771","DOI":"10.1016\/j.ceramint.2026.04.229","article-title":"Plasma-induced optimization of electron trapping for high-k charge trap memories: Mechanistic insights and modeling approaches","volume":"52","author":"Lee","year":"2026","journal-title":"Ceram. Int."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"060909","DOI":"10.1116\/1.5128208","article-title":"Role of plasma properties in controlling crystallinity and phase in oxide films grown by plasma-enhanced atomic layer epitaxy","volume":"37","author":"Boris","year":"2019","journal-title":"J. Vac. Sci. Technol. A"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"094504","DOI":"10.1063\/1.2121929","article-title":"Composition, structure, and electrical characteristics of HfO2 gate dielectrics grown using the remote- and direct-plasma atomic layer deposition methods","volume":"98","author":"Kim","year":"2005","journal-title":"J. Appl. Phys."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"505206","DOI":"10.1088\/1361-6528\/aae4d3","article-title":"Hole and electron trapping in HfO2\/Al2O3 nanolaminated stacks for emerging non-volatile flash memories","volume":"29","author":"Spassov","year":"2018","journal-title":"Nanotechnology"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Kim, S.-W., Yoo, J.-H., Park, W.-J., Lee, C.-H., Lee, J.-H., Kim, J.-H., Uhm, S.-H., and Lee, H.-C. (2024). Enhancing charge trapping performance of hafnia thin films using sequential plasma atomic layer deposition. Nanomaterials, 14.","DOI":"10.3390\/nano14201686"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/0039-6028(71)90092-6","article-title":"Description of the SiO2\u2013Si interface properties by means of very low frequency MOS capacitance measurements","volume":"28","author":"Vapaille","year":"1971","journal-title":"Surf. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"781","DOI":"10.1016\/j.apsusc.2017.06.241","article-title":"Atomic-scale characterization of plasma-induced damage in plasma-enhanced atomic layer deposition","volume":"425","author":"Kim","year":"2017","journal-title":"Appl. Surf. Sci."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Kim, J., Hwang, I., Kim, B., Lee, W., Song, J., Jung, Y., and Yoon, C. (2025). Deposition of HfO2 by Remote Plasma ALD for High-Aspect-Ratio Trench Capacitors in DRAM. Nanomaterials, 15.","DOI":"10.3390\/nano15110783"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1357","DOI":"10.1116\/1.2753846","article-title":"Deposition of TiN and HfO2 in a commercial 200 mm remote plasma atomic layer deposition reactor","volume":"25","author":"Heil","year":"2007","journal-title":"J. Vac. Sci. Technol. A"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"030902","DOI":"10.1116\/1.5088582","article-title":"Status and prospects of plasma-assisted atomic layer deposition","volume":"37","author":"Knoops","year":"2019","journal-title":"J. Vac. Sci. Technol. A"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2870","DOI":"10.1116\/1.574963","article-title":"Plasma enhanced chemical vapor deposition: Differences between direct and remote plasma excitation","volume":"5","author":"Lucovsky","year":"1987","journal-title":"J. Vac. Sci. Technol. A"},{"key":"ref_33","unstructured":"Matsudaira, A., Mehrotra, S.R., Ahmed, S.S., Klimeck, G., and Vasileska, D. (2026, August 01). MOSCap. Available online: https:\/\/nanohub.org\/resources\/moscap."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"121301","DOI":"10.1063\/1.1940727","article-title":"Surface chemistry of atomic layer deposition: A case study for the trimethylaluminum\/water process","volume":"97","author":"Puurunen","year":"2005","journal-title":"J. Appl. Phys."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"412065","DOI":"10.1016\/j.physb.2020.412065","article-title":"Structure and optical properties of HfO2 films on Si (100) substrates prepared by ALD at different temperatures","volume":"584","author":"Li","year":"2020","journal-title":"Phys. B Condens. Matter"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Hwang, I., Kim, J., Lee, J., Jung, Y., and Yoon, C. (2025). Memory Devices with HfO2 Charge-Trapping and TiO2 Channel Layers: Fabrication via Remote and Direct Plasma Atomic Layer Deposition and Comparative Performance Evaluation. Materials, 18.","DOI":"10.3390\/ma18050948"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"884","DOI":"10.1088\/0268-1242\/22\/8\/010","article-title":"Charge trapping characteristics of atomic-layer-deposited HfO2 films with Al2O3 as a blocking oxide for high-density non-volatile memory device applications","volume":"22","author":"Maikap","year":"2007","journal-title":"Semicond. Sci. Technol."},{"key":"ref_38","first-page":"56","article-title":"Extraction of average interface trap density using capacitance-voltage characteristic at SiGe p-FinFET and verification using Terman\u2019s method","volume":"52","author":"Kim","year":"2015","journal-title":"J. Inst. Electron. Inf. Eng."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1109\/14.192236","article-title":"Weibull statistics in short-term dielectric breakdown of thin polyethylene films","volume":"28","author":"Chauvet","year":"1993","journal-title":"IEEE Trans. Electr. Insul."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"3501","DOI":"10.1109\/TED.2016.2588439","article-title":"Charge-trapping phenomena in HfO2-based nonvolatile memories","volume":"63","author":"Yurchuk","year":"2016","journal-title":"IEEE Trans. Electron Devices"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1427","DOI":"10.1109\/LED.2019.2932007","article-title":"A study on the charge trapping characteristics of high-k laminated traps","volume":"40","author":"Yoo","year":"2019","journal-title":"IEEE Electron Device Lett."}],"container-title":["Micromachines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-666X\/17\/8\/965\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T04:16:53Z","timestamp":1787113013000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-666X\/17\/8\/965"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,15]]},"references-count":41,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["mi17080965"],"URL":"https:\/\/doi.org\/10.3390\/mi17080965","relation":{},"ISSN":["2072-666X"],"issn-type":[{"value":"2072-666X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,15]]}}}