Institute of Microelectronics, Chinese Academy of Sciences (IMCAS) has made significant progress in the direction of advanced process simulation
Compared with the traditional FinFET process flow, GAAFET introduces processes such as inner spacer and channel release, which must be realized by precise lateral etching of the stacked structure. High-precision etching process control is one of the biggest challenges for 3D IC fabrication, and its process mechanism and regulation mechanism have received extensive attention in the scientific and industrial communities.
To address the morphological defects and uniformity problems faced by the lateral selective etching process of Si/SiGe stacks with GAA inner sidewall structures, Rui Chen, a researcher at the EDA Center of the Institute of Microelectronics (IMI), in collaboration with Junjie Li, a senior engineer at the Pilot Center, Prof. Zhongrui Wang at the Southern University of Science and Technology (SUSTech), and Prof. Lado Filipovic at the Technical University of Vienna (TUW), has established the Montecarlo-based simulation mechanism based on a Monte Carlo algorithm, by proposing new simulations for the Ge atomic desorption and diffusion By proposing a new simulation algorithm for Ge atom desorption and diffusion, we have established a Monte Carlo-based two-step dry etching process profile simulation model, realized the lateral selective etching process profile simulation for Si/SiGe six-stacked layer structure, and completed the flow experiments of the corresponding structure. Through the combination of topography simulation and transmission electron microscopy (TEM) characterization, the rounding phenomenon on the etched surface of Ge layer and the influence mechanism of cavity air pressure and other parameters on the etching topography uniformity are investigated. This work provides theoretical and experimental references for elucidating the mechanism and optimizing the performance of the new etching process.
The research results were recently published in the top journal of materials field entitled “A Two-Step Dry Etching Model for Non-Uniform Etching Profile in Gate-All-Around Field-Effect Transistor Manufacturing “The research results were published in Small, the top journal in the field of materials, with Ziyi Hu, a master's degree student of the Institute of Microelectronics (IM), as the first author, and Rui Chen, Yayi Wei, and Zhongrui Wang of the Southern University of Science and Technology (SUSTech) as the co-corresponding authors, and were selected as the oral presentation of the flagship conference of the TCAD simulation field, SISPAD 2024. In addition, the research results have been published in ACS Applied Electronic Materials, Journal of Vacuum Science & Technology A, etc., and Senior Engineer Junjie Li of Institute of Microelectronics is the co-corresponding author. This research was supported by the Strategic A Pilot Program of the Chinese Academy of Sciences and the National Natural Science Foundation of China.
