Control of interfacial properties of Pr-oxide/Ge gate stack structure by introduction of nitrogen

摘要

We have demonstrated the control of interfacial properties of Pr-oxide/Ge gate stack structure by the introduction of nitrogen. From C-V characteristics of AI/Pr-oxide/Ge_3N-4/Ge MOS capacitors, the interface state density decreases without the change of the accumulation capacitance after annealing. The TEM and TED measurements reveal that the crystallization of Pr-oxide is enhanced with annealing and the columnar structure of cubic-Pr_2O-3 is formed after annealing. From the depth profiles measured using XPS with Ar sputtering for the Pr-oxide/Ge_3N_4/Ge stack structure, the increase in the Ge component is not observed in a Pr-oxide film and near the interface between a Pr-oxide film and a Ge substrate. In addition, the N component segregates near the interface region, amorphous Pr-oxynitride (PrON) is formed at the interface. As a result, Pr-oxide/PrON/Ge stacked structure without the Ge-oxynitride interlayer is formed. 【Keywords】Ge;Pr-oxide;Radical nitridation;Interface state density;