| AVS 56th International Symposium & Exhibition | |
| Electronic Materials and Processing | Tuesday Sessions |
| Session EM2-TuM |
| Session: | Complex and Multifunctional Oxides |
| Presenter: | K. Watanuki, Tohoku University, Japan |
| Authors: | K. Watanuki, Tohoku University, Japan A. Inokuchi, Tohoku University, Japan A. Banba, Ube-Nittou Kasei Co., Ltd., Japan H. Suzuki, Ube-Nittou Kasei Co., Ltd., Japan T. Koike, Ube-Nittou Kasei Co., Ltd., Japan T. Adachi, Ube-Nittou Kasei Co., Ltd., Japan A. Teramoto, Tohoku University, Japan Y. Shirai, Tohoku University, Japan S. Sugawa, Tohoku University, Japan T. Ohmi, Tohoku University, Japan |
| Correspondent: | Click to Email |
High quality SiO2 film formation is important for many applications as electrical insulator films, protective films for semiconductor, alkali-dissolution barrier films and antireflection films on the glass. In some of applications, the electrical property of the films plays an important role. Various techniques have been used thus far in preparing SiO2 films. Especially, in various techniques, sol-gel technique has significant advantage compared with other techniques with uniformity of thickness, damage free, easy coating of large surfaces, homogeneous multi-component oxide films, controllability of compositions, and potential industrial application. So, in this work, we have evaluated the electrical and structural characteristics of SiO2 film using organosiloxane-based silica precursor. And we have evaluated the influence of additives to organosiloxane-based silica precursor, such as TiO2, HfO2, Ta2O5, ZrO2 and several kinds of metal oxide components on the electrical and structural property of these SiO2 base insulator films.
The organosiloxane-based sol-gel material investigated here is derived from the mixture of tetraethoxysilane (TEOS) and methyltrimethoxysilane (MTMS) by changing the molar ratio of TEOS/MTMS. In the case of the addition of metal oxide to SiO2 matrix, such as TiO2, HfO2, Ta2O5, ZrO2 and several kinds of metal oxide, metal alkoxides such as tetraisopropoxytitanate (TPOT) were added in the concentration ranging from 1 to 15 mol %. In order to evaluate the electrical property of films, we fabricated MOS (Metal-Oxide-Silicon) devices.
By controlling mixing molar ratio between TEOS and MTMS in the sol-gel precursor, the dielectric constant of films can be controlled. This sol-gel precursor was prepared not only of perfect silica film but also a dense film through optimized conditions such as the pre-baking for 5 min at 130˚C, N2 ambience low pressure gas removing process continuously increasing the temperature up to 900˚C, and oxidation process using O2/H2O at 900˚C. In this study, the influence of additives to the sol-gel precursor was examined on the structural and electrical property of the SiO2 based films derived from the sol-gel precursor. The breakdown voltages of the resultant films were effectively improved by adding a small amount of metal oxide such as TiO2, HfO2, Ta2O5 and ZrO2. It was found that the SiO2 based film derived from the sol-gel precursor added with metal oxide components, such as TiO2, HfO2, Ta2O5 and ZrO2, had excellent uniformly-structured Si-O-Metal bond and that the electrical insulation property of the film was improved by the concentration of metal oxide additives.