Calibrating OPC model with full CD profile data for 2D and 3D patterns using scatterometry

The ability to manage critical dimensions (CDs) of structures on IC devices is vital to improving product yield and performance. It is challenging to achieve accurate metrology data as the geometries shrink beyond 40 nm features. At this technology node CDSEM noise and resist LER are of significant concerns1. This paper examines the extendibility of scatterometry techniques to characterize structures that are close to limits of lithographic printing and to extract full profile information for 2D and 3D features for OPC model calibration2. The resist LER concerns are diminished because of the automatic averaging that scatterometry provides over the measurement pad; this represents a significant added value for proper OPC model calibration and verification. This work develops a comparison matrix to determine the impact of scatterometry data on OPC model calibration with conventional CDSEM measurements. The paper will report test results for the OPC model through process data for accuracy and predictability.

[1]  Ir Kusnadi,et al.  SEM image contouring for OPC model calibration and verification , 2007, SPIE Advanced Lithography.

[2]  Weidong Yang,et al.  Line-profile and critical dimension measurements using a normal incidence optical metrology system , 2002, 13th Annual IEEE/SEMI Advanced Semiconductor Manufacturing Conference. Advancing the Science and Technology of Semiconductor Manufacturing. ASMC 2002 (Cat. No.02CH37259).

[3]  Bruno La Fontaine,et al.  Extending scatterometry to the measurements of sub 40 nm features, double patterning structures, and 3D OPC patterns , 2008, SPIE Advanced Lithography.

[4]  Harry J. Levinson,et al.  Evaluating a scatterometry-based focus monitor technique for hyper-NA lithography , 2007, SPIE Advanced Lithography.

[5]  Bruno La Fontaine,et al.  Evaluating diffraction based overlay metrology for double patterning technologies , 2008, SPIE Advanced Lithography.

[6]  Mohamed Al-Imam,et al.  OPC model calibration considerations for data variance , 2008, SPIE Advanced Lithography.

[7]  Shumay Shang,et al.  Etch proximity correction by integrated model-based retargeting and OPC flow , 2007, SPIE Photomask Technology.

[8]  Merritt Funk,et al.  Integrated scatterometry in high-volume manufacturing for polysilicon gate etch control , 2006, SPIE Advanced Lithography.

[9]  Christopher P. Ausschnitt,et al.  Modeling for profile-based process-window metrology , 2004, SPIE Advanced Lithography.

[10]  Harry J. Levinson,et al.  Evaluating the performance of a 193-nm hyper-NA immersion scanner using scatterometry , 2007, SPIE Advanced Lithography.