SPIE ADVANCED LITHOGRAPHY 2010
San Jose Convention Center
Feb 23 - 24, 2010
Nanometrics Booth #221

Presentations:

Scatterometry Characterization of Spacer Double Patterning Structures 
Date: Wednesday, 24 February 2010
Time: 5:20 PM – 5:40 PM

Author(s): Prasad Dasari, Jiangtao Hu, Zhuan Liu, Nanometrics Inc. (United States); Oleg Kritsun, Catherine Volkman, GLOBALFOUNDRIES Inc. (United States); Asher Tan, Nanometrics Inc. (United States)

Abstract: Double patterning (DP) overlay errors result in CD errors and vice versa demanding increased critical dimension uniformity (CDU) and improved overlay control. We will present CD distribution (CDU) and profile characterization for spacer double patterning structures by advanced scatterometry methods. Our result will include NISR, and spectroscopic ellipsometry (SE) characterization of CDU sensitivity in spacer double patterning stack. We will further show the result of two different spacer DP structures by NISR and SE measurements. Metrology comparison at various process steps including litho, etch and spacer and validation of CDU and profile characteristics against CDSEM will be presented.

A Comparison of Advanced Overlay Technologies 
Date: Thursday, 25 February 2010
Time: 10:20 AM – 10:40 AM

Author(s): Prasad Dasari, Nigel P. Smith, Gary Goelzer, Zhuan Liu, Jie Li, Asher Tan, Chin Hwee Koh, Nanometrics Inc. (United States)

Abstract: The extension of optical lithography to 22nm and beyond by Double Patterning Technology is often challenged by CD and overlay control. In this paper, we will report results obtained for DBO targets with different CD and pitch using normal incidence spectral reflectometry (NISR) method. We will present DBO results obtained using model-based regression analysis (mDBO) as well as empirical DBO (eDBO) methods. As an indicator of precise and accurate measurement of overlay errors for advanced nodes we will compare the total measurement uncertainty (TMU) by mDBO, eDBO and IBO measurements. A further testament to the measurement accuracy, we will also report the Optical Mark Fidelity (OMF) for identical targets.

Poster Session:

Advanced Diffraction-Based Overlay for Double Patterning
Date: Tuesday, 23 February 2010
Time: 6:00 PM

Author(s): Jie Li, Yongdong Liu, Prasad Dasari, Jiangtao Hu, Nigel P. Smith, Nanometrics Inc. (United States); Oleg Kritsun, Catherine Volkman, GLOBALFOUNDRIES Inc. (United States)

Abstract: We evaluate and optimize Diffraction-based overlay performance for double patterning process from aspects of target design, hardware configuration, and analysis algorithm. Our target design includes 1D gratings on x and y directions and 2D patterns. We apply both normal incidence spectroscopic reflectometry and ellipsometry measurements. For each of the measurements, data are analyzed using empirical and modeling-based approaches. Data accuracy is checked with image-based overlay (IBO) measurements on bar-in-bar and blossom targets printed nearby. In addition, we report precision, TIS and TMU for DBO measurement.