Fast scatterometric measurement of periodic surface structures in plasma-etching processes
| Autor: | Wolfgang M. Klesse, Lahbib Zealouk, Andreas Rathsfeld, Claudine Groß, Enno Malguth, Oliver Skibitzki |
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| Rok vydání: | 2021 |
| Předmět: |
Fabrication
Materials science Plasma etching Physics::Instrumentation and Detectors business.industry Applied Mathematics 020208 electrical & electronic engineering 010401 analytical chemistry Sparse grid Reconstruction algorithm 02 engineering and technology Condensed Matter Physics 01 natural sciences Computer Science::Other 0104 chemical sciences Metrology Optics Etching (microfabrication) Hardware_INTEGRATEDCIRCUITS 0202 electrical engineering electronic engineering information engineering Microelectronics Electrical and Electronic Engineering business Instrumentation Critical dimension |
| Zdroj: | Measurement. 170:108721 |
| ISSN: | 0263-2241 |
| DOI: | 10.1016/j.measurement.2020.108721 |
| Popis: | To satisfy the continuous demand of ever smaller feature sizes, plasma etching technologies in microelectronics enable the fabrication of device structures in the nanometer range. To control these processes, real-time access to the structure’s dimensions is needed. We develop a special method of optical critical dimension metrology and evaluate the feasibility of reconstructing the etched dimensions from experimental reflectivity spectra of the surface, taken about every second. For a periodic 2D model structure etched into a silicon, we develop and test a fast algorithm. To reduce the computing time, we generate a library of spectra before the etching. We demonstrate that, by replacing the numerically simulated spectra in the reconstruction algorithm by spectra interpolated from the library, it is possible to compute the geometry parameters in times less than a second. Finally, to also reduce memory size and computing time for the library, we reduce the scanning of the parameter values to a sparse grid. |
| Databáze: | OpenAIRE |
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