Effects of annealing gas species on the electrical properties and reliability of Ge MOS capacitors with high-k Y2O3 gate dielectric

In this work, Ge MOS capacitors with Y
₂
O
₃
gate dielectric were fabricated. The effects of annealing in N
₂
, NH
₃
O
₂
or NO ambient were investigated. Experimental results demonstrated that the NO annealing could improve both electrical properties and reliability of Ge MOS devices with Y
₂
O
₃
dielectric. On the other hand, the NH
₃
annealing resulted in H-related traps while the O
₂
annealing suffered from extra GeO
_x
growth, thus both degrading the performance of the devices.