Exploratory studies on wet oxidation grown ternary hafnium tantalum oxide for metal‐oxide semiconductor application

Abstract

Ternary hafnium-doped tantalum oxide (Hf x Ta y O z ) films were successfully obtained after wet oxidation at different temperatures (400-1000 C). A phase transformation from amorphous to crystalline Hf x Ta y O z phases as well as film densification process happened with respect to temperature until 800 C. However, at temperature beyond 800 C, an increase of the thickness was attained as a consequence of film growth and interfacial layer formation. Besides, additional phenomena allied with nitridation and passivation have also happened in the samples. However, formation of N-H complex would decrease the nitridation and passivation due to a reduction of nitrogen and H 2 available at the interface to retard interfacial layer formation as well as minimizing density, effective oxide charges, and slow trap density demonstrated by Hf x Ta y O z for a functional MOS capacitor were investigated.