Small Angle X-Ray Scattering Measurements of Lithographic Patterns with Sidewall Roughness from Vertical Standing Waves


Chengqing Wang, Ronald L. Jones, Eric K. Lin and Wen-Li Wu

Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899

Jim Leu

Department Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan    

Small angle x-ray scattering (SAXS) measurements are used to quantify the wavelength and amplitude of the sidewall roughness in a lithographic line:space pattern due to vertical standing waves present during the photoresist exposure.  Analytic equations are derived to model the x-ray scattering intensity and are used to determine the periodicity and amplitude of the standing wave roughness.   The average periodicity, or pitch, and the line width were L = (422 ± 1) nm and w0 = (148 ± 1) nm.  The period and amplitude of the standing wave roughness were ls = (65 ± 1) nm and As = (3.0 ± 0.5) nm.  These results demonstrate the potential of SAXS measurements to quantify nondestructively and quantitatively dimensional deviations from an ideal structure.


Author information:


Chengqing Wang

Mentor:  Eric K. Lin and Wen-li Wu

Polymers Division

Bldg 224 room A304

MS 8541        

x 5221 (ph)

x 3928 (fax)

not a member of Sigma Xi

Poster Category:  Materials