Subnanometer wavelength metrology of lithographically prepraed structures: a comparison of neutron and X-ray scattering.

The challenges facing current dimensional metrologies based on scanning electron microscopy (SEM), atomic force microscopy (AFM), and light scatterometry for technology nodes of 157 nm imaging and beyond may require the development of new metrologies. We provide results of initial tests of a measurement technique based on Small Angle X-ray Scattering (SAXS) capable of rapid measurements of test samples produced using conventional test masks without significant sample preparation. Using a sample photoresist grating, the technique is shown to apply to both organic, including photoresist, and inorganic patterns, including metal and oxide. The sub-Angstrom wavelength provides nanometer level resolution, with significant room for increased resolution. SAXS provides a dramatic improvement over the use of small angle neutron scattering (SANS) in measurement resolution. An additional advantage is the potential of developing a SAXS-based metrology tool on a laboratory scale.

[1]  Herschel M. Marchman,et al.  Nanometer‐scale dimensional metrology for advanced lithography , 1994 .

[2]  Tilo Baumbach,et al.  X-ray reflection by multilayer surface gratings , 1998 .

[3]  Michael Bishop,et al.  Benchmarking of advanced CD-SEMs at the 130-nm CMOS technology node , 2002, SPIE Advanced Lithography.

[4]  J. McNeil,et al.  Multiparameter grating metrology using optical scatterometry , 1997 .

[6]  Ndubuisi G. Orji,et al.  Silicon single atom steps as AFM height standards , 2001, SPIE Advanced Lithography.

[7]  A. T. Macrander,et al.  X-ray diffraction from corrugated crystalline surfaces and interfaces , 1990 .

[8]  Wen-Li Wu,et al.  Direct Measurement of the Reaction Front in Chemically Amplified Photoresists , 2002, Science.

[9]  Günther Bauer,et al.  High Resolution X-Ray Diffraction , 1996 .

[10]  Kotthaus,et al.  X-ray diffraction from laterally structured surfaces: Total external reflection. , 1995, Physical review. B, Condensed matter.

[11]  Ullrich Pietsch,et al.  Grazing incidence diffraction by epitaxial multilayered gratings , 1998 .

[12]  Hideo Todokoro,et al.  Correction method for high-precision CD measurements on electrostatically charged wafers , 2002, SPIE Advanced Lithography.

[13]  Yoel Cohen,et al.  Scatterometry: interpretation by different methods of electromagnetic simulation , 2002, SPIE Advanced Lithography.

[14]  Shen,et al.  X-ray diffraction from a coherently illuminated Si(001) grating surface. , 1993, Physical review. B, Condensed matter.

[15]  Václav Holý,et al.  High-resolution x-ray diffraction from self-organized PbSe/PbEuTe quantum dot superlattices , 2001 .

[16]  J.J.M. Binsma,et al.  High resolution x‐ray diffraction of periodic surface gratings , 1993 .