Comparative Study of Pore Size of Low-Dielectric-Constant Porous Spin-on-Glass Films Using Different Methods of Nondestructive Instrumentation

Abstract

We consider whether the non-Gaussian scale-dependent halo bias can be used not only to constrain the local form of non-Gaussianity but also to distinguish among different shapes. In particular, we ask whether it can constrain the behavior of the primordial threepoint function in the squeezed limit where one of the momenta is much smaller than the other two. This is potentially interesting since the observation of a three-point function with a squeezed limit that does not go like the local nor equilateral templates would be a signal of non-trivial dynamics during inflation. To this end we use the quasi-single field inflation model of Chen & Wang [1, 2] as a representative two-parameter model, where one parameter governs the amplitude of non-Gaussianity and the other the shape. We also perform a model-independent analysis by parametrizing the scale-dependent bias as a power-law on large scales, where the power is to be constrained from observations. We find that proposed large-scale structure surveys (with characteristics similar to the dark energy task force stage IV surveys) have the potential to distinguish among the squeezed limit behavior of different bispectrum shapes for a wide range of fiducial model parameters. Thus the halo bias can help discriminate between different models of inflation.

Reflectance of surfactant-templated mesoporous silica thin films: Simulations versus experiments

“…Mesoporous silica has been intensively studied in the last two decades due to the simplicity of their synthesis [1] and for their numerous applications including low-k dielectrics [2][3][4], photocatalysis [5], optical materials [2,3,6], thermal insulation [7], optical data storage [8], corrosion-resistant catalyst supports [9], as well as drug delivery and biosensors [10][11][12]. Those materials can assume various shapes such as spheres, fibers, and thin-films [1].…”

Variable-Energy Positron Annihilation as Highly Sensitive Nanoporosimetry for Porous Thin Films

“…For more accurate pore size determination, as mentioned above, calibration between o-Ps lifetimes and pore sizes for thin films must be accomplished. An international round robin test of various porous low-k films was performed by the groups of University Yamanashi, IMEC (Belgium), NIST (USA) and University Michigan (USA) to compare the results of PAL, small angle neutron scattering, ellipsometric porosimetry, and conventional gas adsorption [17].…”

Characterization of porous low-k films using variable angle spectroscopic ellipsometry

“…4 The pore size should be carefully controlled and should be smaller than the minimum features size to achieve mechanical stability. 5 It is also preferable to have a homogenous pore size distribution to prevent k anisotropy. Thus, characterizations of porous films are becoming crucial and increasingly difficult.…”