Modified Shape From Shading Approach To Sem Based Photoresist Cd Metrology
3D shape reconstruction; CD-SEM; Critical dimension metrology; Photo-resist; Semiconductor metrology; Shape from shading
As the fabrication density increases in semiconductor manufacturing processes, cost effective determination of the exact dimensions of various device-interconnects becomes a critical issue. Single detector based critical dimension metrology systems are attractive due to cost effectiveness. Yet, deducing dimensions like sidewall curvature and 3D shape of the semiconductor surface are quite difficult using a single detector system. Non-destructive metrological systems are also very desirable in evaluating critical dimension and manufacturing error because they are inexpensive compared to multi-detector systems. In our paper, we build upon the physical modeling approach to modify a classical shape from shading algorithm to reconstruct the 3D shape from a single non-stereoscopic SEM image. Our ultimate aim is to design an efficient real-time, non-destructive CD-SEM system using a single detector. Appropriate reflectance function is utilized for low-excitation SEM imagery for reconstructing the depth map of the surface using the shape from shading algorithm. In this paper, we present the results from low-excitation SEM reflectance model used for SFS approach. We compare the results with a standard SFS algorithm that uses Lambertian reflectance model. We also discuss the advantages of this computer vision based approach compared to other destructive CD-SEM technologies.
Proceedings of SPIE - The International Society for Optical Engineering
Number of Pages
Article; Proceedings Paper
Source API URL
Ahammad, Parvez and Mukherjee, Amar, "Modified Shape From Shading Approach To Sem Based Photoresist Cd Metrology" (2002). Scopus Export 2000s. 2327.