High Quality Germanium Oxide Thin Films: Deposition and Characterization

This thesis focuses on the deposition and characterization of a germanium oxide film with a quartz like structure. Germanium has long been considered a promising candidate to replace Silicon as the channel material is a wide range of semiconductor devices, but the lack of a high quality gate dielectric has rendered the material unsuitable. This thesis presents a method of depositing a high quality germanium oxide dielectric that has an amorphous quartz like structure and is qualitatively different from the native oxide of germanium.;Remote Plasma Enhanced Chemical Vapor Depsosition (RPECVD) was used to deposit a film of germanium oxide on both silicon and germanium substrates. RPECVD allows for a lower effective temperature deposition, between 100° C and 450°C at the substrate. Additionally, RPECVD enables selective excitation of process gasses, in this case a oxygen helium mixture was remotely excited via plasma resonance and the germane gas was injected downstream.;This material was studied using Xray absorption spectroscopy. The XAS spectroscopic studies demonstrated that the germanium film had a quartz like structure. Second Derivative studies in the pre edge of the oxygen k region showed a defect that grew with annealing temperature. The film became increasing defective as the annealing temperature was increased beyond 600 centigrade.;The film was also studied using Xray photoemssion spectroscopy, which showed no evidence of a suboxide feature which grew in the annealed films and in films grown by other methods. The detected defect under XAS was not visible in the valence band via XPS. From spectroscopic ellipsometry, an absorption at 6 eV was detected that increased with annealing temperature, but was substantially reduced compared to other GeO2 films.