Open AccessPore size distributions in low‐ k dielectric thin films from X‐ray porosimetry
Author(s) -
Lee HaeJeong,
Soles Christopher L.,
Liu DaWei,
Bauer Barry J.,
Wu WenLi
Publication year - 2002
Publication title -
journal of polymer science part b: polymer physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.65
H-Index - 145
eISSN - 1099-0488
pISSN - 0887-6266
DOI - 10.1002/polb.10275
Subject(s) - nanoporous , wafer , dielectric , porosimetry , kelvin equation , partial pressure , low k dielectric , analytical chemistry (journal) , thin film , capillary condensation , vapor pressure , porosity , materials science , condensation , chemical vapor deposition , chemistry , adsorption , porous medium , nanotechnology , composite material , thermodynamics , oxygen , chromatography , organic chemistry , optoelectronics , physics
X‐ray reflectivity has been used to determine the mass uptake of probe molecules in porous thin films supported on thick silicon wafers. The adsorption occurs by capillary condensation when the films are exposed to probe vapor at controlled partial vapor pressures. The probe solvent partial pressure was varied by mixing saturated air and dry air at constant temperature or by changing sample temperature at a constant vapor concentration. Pore size distribution in the films can be calculated from the probe uptake with typical porosimetric approaches such as the application of the Kelvin equation to convert partial pressure into pore size. For illustration, the pore size distribution of three different nanoporous thin films, the primary candidate of ultra‐low‐ k interlevel dielectrics in the next generation of integrated circuit chips, was determined with this technique. These samples represent different generations of low‐ k dielectrics developed by industry. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2170–2177, 2002