International Journal of Advancements in Electronics and Electrical Engineering
Author(s) : HARUKA FUJIWARA , HIROSHI YAMADA , MITARO NAMIKI , TOMO UENO , YOSHITAKA IWAZAKI
Si has been widely used as primary semiconductor materials for electronic device fabrication. Due to the limitation of its electrical properties such as electron and hole mobilities, however, Ge would be one of the candidates for future electronic device materials because of its higher mobilities of both carriers. However, since GeO2 which composed of Ge-O chemical bonds is known to have water solubility and it reacts with Ge substrates at high temperature,it is well known that GeO desorption occurs at GeO2/Ge interface during higher temperature annealing, as well as during the course of higher temperature oxidation process itself. In this research, we attempted to improve interface characteristics by depositing Hf on the GeO2/Ge structure and applying heat treatment (PMA: Post Metallization Annealing).As a result, it is clearly shown that the decrease of Dit value by the PMA, and the leakage current was reduced and insulating property was improved by applying PMA. We consider that a slight amount of Hf buried the GeO2 film by Hf-PMA and the bonding strength of Ge-O became stable. It was confirmed that Hf-PMA is effective for GeO2/Ge stacked structure as a solution to reduce the Dit values.