OFF-SPECULAR NEUTRON AND X-RAY REFLECTIVITY FOR THE INVESTIGATION OF BURIED INTERFACES

Kristopher A. Lavery, Vivek M. Prabhu, Eric K. Lin, Wen-li Wu

NIST Polymers Division

Kwang-Woo Choi

Intel Corporation

Sushil K. Satija

NIST Center for Neutron Research

Matthew Wormington

Bede X-ray Metrology

Off-specular reflectivity is a non-destructive scattering technique that is sensitive to lateral compositional variations at surfaces and interfaces.  It is particularly well-suited as a means of measuring the form and amplitude of surface roughness, as well as separating contributions from physical roughness and gradients in material density.  Model rough surfaces were prepared on float glass substrates and the roughness and lateral correlation lengths were cross-correlated using neutron and x-ray off-specular reflectivity, and using power spectral density analysis of atomic force microscopy (AFM) data.  The technique was extended to observe the lateral correlation length of the reaction-diffusion front in a model photoresist using a polymer-polymer bilayer designed to mimic an ideal lithographic line edge.  These experiments highlight the advantages of the technique for the investigation of buried interfaces while illustrating how x-ray and neutron techniques work complementarily to measure interfacial roughness.

Name:  Kristopher Lavery

Mentor:  Wen-li Wu

Division:  Polymers (854)

Laboratory:  MSEL

Room:  A227

Building:  224

Mail Stop:  8541

Telephone:  (301) 975-6736

Fax:  (301) 975-3928

Email:  kristopher.lavery@nist.gov

Sigma Xi member?:  No

Category:  Materials