Systematic investigation of CD metrology tool response to sidewall profile variation on a COG test mask

Different type of CD metrology instrumentation is in use today for production control of photomasks, namely SEM, AFM as well as optical microscopy and optical scatterometry is emerging, too. One of the challenges in CD metrology is to develop a system of cross calibration which allows a meaningful comparison of the measurement results of the different systems operated within a production environment. Here it is of special importance to understand and also to be able to simulate the response of different metrology instrumentation to variations in sidewall profile of features on photomasks. We will report on the preparation of a special COG test mask with an intended variation of sidewall features and the subsequent metrological characterization of this mask in different type of CD instrumentation. The discussion of the measurement results will be accompanied by a discussion of the simulation of instrument response to feature sidewall variation.

[1]  C. G. Frase,et al.  Results of a round robin measurement on a new CD mask standard , 2005, Other Conferences.

[2]  Wolfgang Haessler-Grohne,et al.  Characterization of a 100-nm 1D pitch standard by metrological SEM and SFM , 2004, SPIE Advanced Lithography.

[3]  Ludwig Reimer,et al.  Monte Carlo Simulation Program with a Free Configuration of Specimen and Detector Geometries , 1996 .

[4]  Harald Bosse,et al.  Impact of EUV mask pattern profile shape on CD measured by CD-SEM , 2005, SPIE Advanced Lithography.

[5]  Bernd Bodermann,et al.  Comparison of different approaches for modelling microscope images on the basis of rigorous diffraction calculation , 2005, SPIE Optical Metrology.

[6]  Harald Bosse,et al.  An electron optical metrology system for pattern placement measurements , 1998 .

[7]  M. Totzeck,et al.  Numerical simulation of high-NA quantitative polarization microscopy and corresponding near-fields , 2001 .

[8]  T. Gaylord,et al.  Formulation for stable and efficient implementation of the rigorous coupled-wave analysis of binary gratings , 1995 .

[9]  Thomas K. Gaylord,et al.  Stable implementation of the rigorous coupled-wave analysis for surface-relief gratings: enhanced transmittance matrix approach , 1995 .

[10]  Charles N. Archie,et al.  Reducing measurement uncertainty drives the use of multiple technologies for supporting metrology , 2004, SPIE Advanced Lithography.

[11]  Harald Bosse,et al.  Analysis and Comparison of CD‐SEM Edge Operators: A Contribution to Feature Width Metrology , 2006 .