Properties of a-SiOx:H thin films deposited from hydrogen silsesquioxane resins

Ultralarge sale integrated circuit designs require multiple metal wiring layers for the formation of the device interconnections. Surface planarization and the deposition of high quality insulating films are critical fabrication steps related to the manufacture of these circuits. Planarization and dielectric deposition can be accomplished simultaneously using a spin-on process with hydrogen silsesquioxane (HSQ) resin to deposit amorphous SiO:H dielectric films. The use of this material in device manufacturing has increased as a result of the material's good planarization properties, eliminating the need for etchback procedures. More recently, it has been observed that HSQ-based films also provide the added benefit of relative permittivity less than SiO2, which helps to minimize electrical delay In order to obtain optimum properties from this material, tight process control and knowledge of the material's chemical behavior are necessary. Studies of the precursor material, film formation, and film properties have been performed. Also it is found that structural and compositional changes in the precursor during the film forming process play an important role in establishing the beneficial properties observed in HSQ-based dielectric films.