{"title":"Incorporation of tungsten or cobalt into TaN barrier layers controls morphology of deposited copper","authors":"Cara-Lena Nies, M. Nolan","doi":"10.1088/2515-7639/acdeaa","DOIUrl":null,"url":null,"abstract":"Progress in semiconductor devices, which has enabled the information and communications technology explosion of the 21st century, has been driven by Moore’s Law and the accompanying aggressive scaling of transistors. However, it is now acknowledged that the currently used copper interconnects are becoming a bottleneck in sub-nm scaling. Semiconductor devices require a diffusion barrier and a seed layer in the volume available to the interconnect metal. This then limits the minimum size of the interconnect and copper suffers from a preference to form 3D islands which are non-conducting rather than conducting films. Therefore there is a pressing need to either replace copper, which has its own difficulties, or to reduce the volume taken up by the diffusion barrier and liner; ideally finding a single material displaying both properties is needed. We have previously shown that incorporation of Ru into the surface layer of TaN is a strong alternative to the usual TaN/Ta or TaN/Ru stacks. In this work we study other possible metals that can be incorporated into TaN, namely Co and W, which are less expensive and critical than Ru and can potentially outperform it. Our first principles density functional theory results from static relaxations and ab initio molecular dynamics show that there are several compositions of both Co- and W-doped TaN which should promote growth of 2D copper interconnects without compromising the barrier properties of TaN. With this selection of materials it should be possible to design new experimental processes that promote downscaled copper interconnects for the next generation of electronic devices. Additionally, our work presents an improved method towards prediction of thin film morphology on a given substrate, which can be of use for a variety of materials science applications.","PeriodicalId":16520,"journal":{"name":"Journal of Nonlinear Optical Physics & Materials","volume":null,"pages":null},"PeriodicalIF":2.9000,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Nonlinear Optical Physics & Materials","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1088/2515-7639/acdeaa","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"OPTICS","Score":null,"Total":0}
引用次数: 0
Abstract
Progress in semiconductor devices, which has enabled the information and communications technology explosion of the 21st century, has been driven by Moore’s Law and the accompanying aggressive scaling of transistors. However, it is now acknowledged that the currently used copper interconnects are becoming a bottleneck in sub-nm scaling. Semiconductor devices require a diffusion barrier and a seed layer in the volume available to the interconnect metal. This then limits the minimum size of the interconnect and copper suffers from a preference to form 3D islands which are non-conducting rather than conducting films. Therefore there is a pressing need to either replace copper, which has its own difficulties, or to reduce the volume taken up by the diffusion barrier and liner; ideally finding a single material displaying both properties is needed. We have previously shown that incorporation of Ru into the surface layer of TaN is a strong alternative to the usual TaN/Ta or TaN/Ru stacks. In this work we study other possible metals that can be incorporated into TaN, namely Co and W, which are less expensive and critical than Ru and can potentially outperform it. Our first principles density functional theory results from static relaxations and ab initio molecular dynamics show that there are several compositions of both Co- and W-doped TaN which should promote growth of 2D copper interconnects without compromising the barrier properties of TaN. With this selection of materials it should be possible to design new experimental processes that promote downscaled copper interconnects for the next generation of electronic devices. Additionally, our work presents an improved method towards prediction of thin film morphology on a given substrate, which can be of use for a variety of materials science applications.
期刊介绍:
This journal is devoted to the rapidly advancing research and development in the field of nonlinear interactions of light with matter. Topics of interest include, but are not limited to, nonlinear optical materials, metamaterials and plasmonics, nano-photonic structures, stimulated scatterings, harmonic generations, wave mixing, real time holography, guided waves and solitons, bistabilities, instabilities and nonlinear dynamics, and their applications in laser and coherent lightwave amplification, guiding, switching, modulation, communication and information processing. Original papers, comprehensive reviews and rapid communications reporting original theories and observations are sought for in these and related areas. This journal will also publish proceedings of important international meetings and workshops. It is intended for graduate students, scientists and researchers in academic, industrial and government research institutions.