| 초록 |
Porous organosilicate materials have recently attracted interests because of their potential applications such as low dielectric constant (low-k) interdielectrics, chemical- and bio-sensor membranes, catalyst supports, and gas separation membranes. One major route for producing porous organosilicates is the templated sol-gel synthesis of silane derivatives in the presence of labile porogens such as organic surfactants and polymers. Subsequent removal of the porogen templates generates pores in the resultant organosilicates. In particular, much effort has been exerted to develop low-k porous organosilicate dielectric thin films by the templated polycondensations of their soluble precursors in the presence of thermally labile organic polymeric and subsequently creating pores in the resulting dielectrics through the sacrificial thermal decomposition of the porogens at temperatures in the range 350–400C. However, the tendency of porogens to aggregate in organosilicates has limited the pore size reduction and porosity of the resulting dielectrics, making them unsuitable for use in advanced integrated circuits with small feature sizes. In this study, we present in-situ grazing incidence small angle X-ray scattering (GISAXS) study on the evolution of nanopores during the porous dielectric film formation process from composite films of soluble polymethylsilsesquioxane precursor with various porogens. We successfully analyzed in detail the measured two-dimensional GISAXS data with a GISAXS formula, which we recently developed, and then delivered structural characteristics of the composite films and resulting porous films: miscibility of precursor matrix and porogen, phase separartion, pore generation mechanism, pore size and size distribution, film electron density, and film porosity. |
