Atomic layer deposition of rare-earth oxides and aluminum catalyzed silica

Atomic layer deposition (ALD) is a deposition technique that has become increasingly used to produce high quality thin films within demanding device architectures. One of the challenges of ALD is to develop appropriate precursor chemistry in order to deposit the material of choice. The development of a successful ALD process is also dependent on the application.; The impetus behind much of the work presented in this thesis is the deposition of high quality dielectric films for use in scaling down gate dimensions, capacitor footprints in DRAM, and for optical applications. In order to scale down gate and capacitor dimensions it is necessary to look at alternative materials to silicon dioxide. Some current and all future generations of integrated circuits will require the use of some type of ALD process. My work on alternative gate and capacitor dielectrics has focused on rare-earth and lanthanide oxides including: La2O3, LaAlO3, Pr2O 3, PrAlO3, Y2O3, and Sc2O 3. The metalorganic precursors were synthesized and purified for the express goal of film deposition. The precursors used for deposition of these high-k materials are based on the tris(N,N'-diisopropylacetamidinate) ligand with the following general formula X(iPr2-Me-amd) 3, where X = (La, Pr, Y, Sc). The deposition of the thin films was performed on home built ALD reactors. The films were fully characterized for physical, electronic, and optical properties.; Another thrust of the research and results shown will be on applications of an aluminum catalyzed silica ALD process. The reaction involves an aluminum catalyzed polymerization of alkyl silanol precursors that produces an amorphous silica thin film. Chemical selectivity afforded to this reaction by the presence of a surface catalyst makes it possible to deposit silica films with control over film location. Using this concept we demonstrated that a porous ultra low-k material can be capped with a silica film on the surface and on the sidewalls of a via structure. The silica process was also used in several applications where electrical isolation is required such as shallow trench isolation. The work was supported with a theoretical examination of reaction mechanisms and a thorough analysis of ALD behavior.