{"title":"SiO2/Si interface defects in HKMG stack fabrication","authors":"Shota Nunomura , Yukinori Morita","doi":"10.1016/j.surfin.2024.105445","DOIUrl":null,"url":null,"abstract":"<div><div>The defect generation and recovery near the silicon dioxide (SiO<sub>2</sub>)/silicon (Si) interface are studied throughout high-k dielectric/metal gate (HKMG) stack fabrication and post-processing. The HKMG stack is prepared on a Si wafer in a well-established manner, using chemical oxidation for an interfacial layer of SiO<sub>2</sub>, atomic layer deposition (ALD) for HK-hafnium oxide (HfO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>), and magnetron sputtering for MG-tantalum nitride (TaN). The stack is then treated with additional processing of post-deposition annealing (PDA), oxygen (O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>) plasma processing, and forming gas annealing (FGA) to imitate transistor manufacturing. Throughout these processing, the atomic-level defects near the SiO<sub>2</sub>/Si interface are characterized, with quasi-steady-state photoconductance (QSSPC) measurements. With the measurements, it is found that the defects near the SiO<sub>2</sub>/Si interface are generated by most of the processing of ALD-HfO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, sputter-TaN as well as PDA and O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> plasma, whereas those defects are recovered by the last step of FGA. Interestingly, the recovery of defects depends on the HKMG stack structure and processing; the recovery is highly limited for a thin stack treated with high-temperature PDA. In such a case, residual defects are created near the SiO<sub>2</sub>/Si interface.</div></div>","PeriodicalId":22081,"journal":{"name":"Surfaces and Interfaces","volume":"56 ","pages":"Article 105445"},"PeriodicalIF":5.7000,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Surfaces and Interfaces","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2468023024016018","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The defect generation and recovery near the silicon dioxide (SiO2)/silicon (Si) interface are studied throughout high-k dielectric/metal gate (HKMG) stack fabrication and post-processing. The HKMG stack is prepared on a Si wafer in a well-established manner, using chemical oxidation for an interfacial layer of SiO2, atomic layer deposition (ALD) for HK-hafnium oxide (HfO), and magnetron sputtering for MG-tantalum nitride (TaN). The stack is then treated with additional processing of post-deposition annealing (PDA), oxygen (O) plasma processing, and forming gas annealing (FGA) to imitate transistor manufacturing. Throughout these processing, the atomic-level defects near the SiO2/Si interface are characterized, with quasi-steady-state photoconductance (QSSPC) measurements. With the measurements, it is found that the defects near the SiO2/Si interface are generated by most of the processing of ALD-HfO, sputter-TaN as well as PDA and O plasma, whereas those defects are recovered by the last step of FGA. Interestingly, the recovery of defects depends on the HKMG stack structure and processing; the recovery is highly limited for a thin stack treated with high-temperature PDA. In such a case, residual defects are created near the SiO2/Si interface.
期刊介绍:
The aim of the journal is to provide a respectful outlet for ''sound science'' papers in all research areas on surfaces and interfaces. We define sound science papers as papers that describe new and well-executed research, but that do not necessarily provide brand new insights or are merely a description of research results.
Surfaces and Interfaces publishes research papers in all fields of surface science which may not always find the right home on first submission to our Elsevier sister journals (Applied Surface, Surface and Coatings Technology, Thin Solid Films)