1. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. (a) The working principle of the tilt-beam CD-SEM. The feature of interest is imaged twice with an electron beam at two different incident angles (α1 and α2), thus creating two images with different edge widths (E1 and E2). Height and sidewall angle can be calculated based on the mathematical relation of α1, α2, E1, and E2. (b) Images of the same structure illuminated with top-down beam, low-tilt beam, and high-tilt beam. Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407

2. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. Illustration of the limitation on the tilting angle due to the feature aspect ratio. Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407

3. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. Two parameters crucial to process control that will be addressed by the tilt-beam CD-SEM in this study, the gate height over the fin and the fin height. Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407

4. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. Schematic drawing of the FinFET structure at the step after poly removal and high K deposition in a gate last process. The structure has lines consisted of SiGe/oxide/nitride spacer covered by high K/work function material, lying in perpendicular direction over the fins. (a) three-dimensional (3-D) rendering of the FinFET structure at this step. (b) two-dimensional cross section of the structure. (c) Transmission electron microscope (TEM) cross section of the structure. Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407

5. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. Correlation of the tilt-beam measurement with TEM on (a) and (b) semidense features and on (c) isolated features. (d) Overall correlation of all features. Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407

6. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. (a)–(c) Full wafer map plot showing measurement of die-to-die process variation on gate height. (d) Bar chart of in-die features at different design of experiment (DOE) conditions demonstrates sensitivity to in-die process variation. Each bar represents the average gate height of an individual in-die feature throughout a wafer at each DOE condition. Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407

7. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. Run-chart of 1 month of the inline data of the N-type semidense device (a), N-type isolated device (b), and P-type semidense device (c). Data in red circles are process excursions caused by missing pull-down (d). Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407

8. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. TEM image (a) and 3-D illustration (b) of the fin structure for the fin height measurement. The fins are filled with oxide for isolation followed by oxide etch step to reveal the top of the fins. The measurement is performed on the revealed fin height. Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407

9. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. (a) TEM and (b) tilt-beam data showing consistent sensitivity to center-edge variation and DOE built-in variation on OCD target, in- die electrical 1 target, and electrical 2 target. TEM reference data are plotted on the left, while tilt-beam data on the right. In every plot, center and edge data are compared at each DOE condition. Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407

10. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. (a) Overall correlation of the tilt-beam measurement with TEM on all in-die features. (b)–(d) Correlation of TEM and tilt beam on semidense optical critical dimension (OCD) (b), in-die electrical 1 (c) and in-die electrical 2 (d). Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407

11. Date of download: 6/3/2016 Copyright © 2016 SPIE. All rights reserved. (a) Illustration of the challenges of the fin structure with rounded edges for tilt-beam measurement. The image on the left is a TEM image of a typical in-die fin structure with rounded profile highlighted in red. On the right is the tilted SEM image of this structure that shows the difficulty to define the fin top edge from the image. The right fin in the same image produces much weaker bottom signal compared to the left fin due to reabsorption of secondary electrons by the fin sidewall. (b) Measurement scheme of the edge width method and the line method. Figure Legend: From: Addressing FinFET metrology challenges in 1× node using tilt-beam critical dimension scanning electron microscope J. Micro/Nanolith. MEMS MOEMS. 2014;13(4):041407. doi:10.1117/1.JMM.13.4.041407