An Investigation of Metal Contamination Effects on the Electrical Characteristic of High-k HfO2 Film as Gate Dielectric
The manufacturing process of semi-conductors has gradually minimized. The using silicon dioxide as a dielectric layer has no longer met the require- ments of semi-conductor industries and faced the problem of replacing with a new material. The thesis is based on the idea of using HfO2, a high dielectric and stable material, and carry out researches on metal pollution during the pr- eceding process phase. The thesis hypothesizes that the chemical solution has created Hafnium pollution and uses Metal-Oxide-Semiconductor (MOS) capacity as mimic to measure its features of flat-band voltage. It also tries to discuss the possible pollution of Hafnium to P/N connecting surface. According to the result, of the pollution in two solutions, which are diluted hydrofluoric acid and APM, the pollution level in APM is more obvious. The chips that have been dipped in clean diluted hydrofluoric acid after being dipped into the APM have improvement in electric conductivity. During the MOS man- ufacturing process, if we use hafnium dioxide as the conductivity layer, we sho- uld get rid of excessive hafnium dioxide before the ion implantation. This can prevent the feature of connection-level from being affected by the pollutants in hafnium dioxide by the ion implantation manufacturing process.