Plasma–surface interactions for advanced plasma etching processes in nanoscale ULSI device fabrication: A numerical and experimental study

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• 作者：Kouichi Ono ; Hiroaki Ohta ; Koji Eriguchi
• 关键词：Plasma etching ; Cl- and Br-based plasmas ; Silicon ; High-k dielectrics ; Metal electrode materials ; Profile simulation ; MD simulation ; ULSI
• 刊名：Thin Solid Films
• 出版年：2010
• 出版时间：30 April 2010
• 年：2010
• 卷：518
• 期：13
• 页码：3461-3468
• 全文大小：1217 K

文摘

Plasma–surface interactions in Cl- and Br-based plasmas have been studied for advanced front-end-of-line (FEOL) etching processes in nanoscale ULSI device fabrication. A Monte Carlo-based atomic-scale cellular model (ASCeM) was developed to simulate the feature profile evolution on nanometer scale during Si etching in Cl₂ and Cl₂/O₂ plasmas, including surface oxidation, inhibitor deposition, and ion reflection and penetration on surfaces. A classical molecular dynamics (MD) simulation for Si/Br and Si/HBr as well as Si/Cl systems was also developed, along with an improved Stillinger–Weber interatomic potential model for Si/halogen interactions, to clarify surface reaction kinetics on atomic scale during Si etching in Cl₂ and HBr plasmas. The numerical results revealed the origin of profile or surface anomalies such as microtrench, roughness, and residue, and also etching fundamentals such as etch yield, product stoichiometry, and atomistic surface structures. Moreover, the etching of high-k dielectric and metal electrode materials, such as HfO₂ and TaN, was investigated in BCl₃- and Cl₂-containing plasmas with and without rf biasing, to gain an understanding of the etch mechanisms and to achieve anisotropic and selective etching of metal/high-k gate stacks.