Publisher Summary This chapter focuses on the latest developments in the synthesis and characterization of pure-silica-zeolites as low-k materials. To reduce the resistance component of the RC (resistance–capacitance) delay, the semiconductor industry has developed a Damascene process to switch from aluminum to copper. The capacitance comes into play in the dielectric material, which has traditionally been dense silica with a dielectric constant (k) of about 4. A number of new low-k materials with a variety of chemical compositions have been evaluated. Two important factors in their exploration are the polarizability and number density of the materials' molecules; ideally, both quantities should be low. Three major classes of materials have been studied: organic polymers, carbon-doped oxides and silica-based materials. Zeolites are microporous crystalline oxides that have traditionally been used as catalysts in the oil refining industry, and they contain a number of desirable attributes that make them a suitable replacement low-k material. Recently, new and novel applications for zeolite thin films have been developed. Zeolite films can be prepared through several methods including in situ, seeded growth and spin-on techniques. The films are characterized for k value, pore structure, hydrophobicity, and mechanical properties. PSZ thin films have been shown to be promising candidates for new low-k materials. Their spin-on deposition process and silica chemical composition allow PSZs to be easily integrated into the semiconductor manufacturing process, revealing a k value of 1.5. This meets the necessary requirements for a low-k material. Before they can be completely accepted as a suitable low-k alternative, other properties of PSZs must be fully characterized and optimized. These include, but are not limited to, thermal properties, electrical properties, and chemical compatibility.