Hydrosilsesquioxane resin compositions having improved thin film properties

The present invention relates to dielectric coatings in semiconductor devices. More particularly, it relates to dielectric coatings formed from siloxane-based resins and having relatively low dielectric constant, relatively low SiH content, and relatively high modulus. Herein is disclosed a resin solution, comprising (a) about 0.1 solids wt % to about 50 solids wt % of an organosiloxane resin comprising the formula (RSiO)(R′SiO), wherein R is selected from the group consisting of C-Calkyl, C-Calkenyl, C-Calkoxy, C-Calkenoxy, and C-Csubstituted hydrocarbon; R′ is selected from the group consisting of -H, C-Cunsubstituted hydrocarbon, and C-Csubstituted hydrocarbon; x is from about 5 mole % to about 75 mole %; y is from about 10 mole % to about 95 mole %; and x+y is at least about 40 mole %; and (b) about 50 solids wt % to about 99.9 solids wt % of a resin comprising at least about 90 mole % of the formula HSiO. Also disclosed herein is a method of preparing such a resin solution, as well as a method of preparing a solid coating, comprising (i) coating the resin solution on a surface; (ii) removing the solvent from the resin solution; (iii) removing R groups from the organosiloxane resin; and (iv) curing the resin solution, to form the solid coating. Coatings prepared from the resins disclosed herein have relatively low dielectric constants and also have relatively low SiH content and relatively high modulus.