N incorporation into ALD HfO/sub 2/ gate dielectric using ion implantation [MOSFET application]

A fabrication process for HfON, using ion implantation of N/sub 2/ in ALD HfO/sub 2/, was demonstrated. Results showed that a good quality HfON could be formed by N/sub 2/ implantation, which suggests nitrogen implantation can be an alternative high-k nitridation technique. This process was successfully integrated into a traditional CMOS flow and the electrical and reliability results of HfON, as compared to HfO/sub 2/, showed 10 times less Vt shift in the pulsed Id-Vg measurement and up to 70% gate leakage reduction. In addition, EOT, electron/hole mobility, TDDB and subthreshold slope of HfON also performed better than those of HfO/sub 2/. A model is proposed to explain the result by attributing the improvement to the reduction of defect states (oxygen vacancies) in the HfO/sub 2/ film by the presence of N in the HfON film.