| Autor: |
Chanha Park, Minhyung Hong, Sangjun Han, John C. Robinson, Jieun Lee, Tal Marciano, Zephyr Liu, Dana Klein, Dongsub Choi, Roie Volkovich, Ahlin Choi, Hao Mei, Eitan Hajaj, Dohwa Lee, Lilach Saltoun, Jung-Tae Lee, Eitan Herzel, Wayne (Wei) Zhou, Dongyoung Lee, Anna Golotsvan, Jeongpyo Lee, Honggoo Lee, Eran Amit, Sanghuck Jeon, Seongjae Lee |
| Rok vydání: |
2019 |
| Předmět: |
|
| Zdroj: |
Metrology, Inspection, and Process Control for Microlithography XXXIII. |
| DOI: |
10.1117/12.2515015 |
| Popis: |
Overlay process control is a critical aspect of integrated circuit manufacturing. Advanced DRAM manufacturing overlay error budget approaches the sub-2nm threshold, including all sources of overlay error: litho processing, non-litho processing, metrology error, etc. Overlay measurement quality, both for accuracy and robustness, depends on the metrology system and its recipe setup. The optimal configuration depends on the layer and materials involved. Increased flexibility of metrology setup is of paramount importance, paired with improved methods of recipe optimization. Both optical image-based overlay (IBO) and scatterometry diffraction overlay (SCOL®) are necessary tools for overlay control. For some devices and layers IBO provides the best accuracy and robustness, while on others SCOL provides optimum metrology. Historically, wavelength selection was limited to discrete wavelengths and at only a single wavelength. At advanced nodes IBO and SCOL require wavelength tunability and multiple wavelengths to optimize accuracy and robustness, as well as options for polarization and numerical aperture (NA). In previous studies1,2,3 we investigated wavelength tunability analysis with landscape analysis, using analytic techniques to determine the optimal setup. In this report we show advancements in the landscape analysis technique for IBO through both focus and wavelength, and comparisons to SCOL. A key advantage of imaging is the ability to optimize wavelength on a per-layer basis. This can be a benefit for EUV layers in combination with those of 193i, for example, as well as other applications such as thick 3D NAND layers. The goal is to make accurate and robust overlay metrology that is immune from process stack variations, and to provide metrics that indicate the quality of metrology performance. Through both simulation and on-wafer advanced DRAM measurements, we show quantitative benefits of accuracy and robustness to process stack variability for IBO and SCOL applications. Methodologies described in this work can be achieved using Archer™ overlay metrology systems, ATL™ overlay metrology systems, and 5D Analyzer® advanced data analysis and patterning control solution. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
