Chemical Stability of IrO ₂ Top Electrodes in Ferroelectric Hf _0.5 Zr _0.5 O ₂ ?Based Metal–Insulator–Metal Structures: The Impact of Annealing Gas

The IrO2 top electrode chemistry of ferroelectric IrO2/Hf0.5Zr0.5O2 (HZO)/IrO2 metal–insulator–metal (MIM) structures dependent on rapid thermal annealing in different gas atmospheres (nitrogen, oxygen, and forming [FG]) is investigated. Using hard X-ray photoelectron spectroscopy (HAXPES), the strongly modified chemical states layer choice atmosphere are observed. For O2 N2 anneals, remains either unaffected or just slightly chemically attacked at top. In contrast, FG causes a complete reduction into metallic Ir. Surprisingly, oxygen detected—unbound to Ir—which incorporated Ir layer. This mobile thought affect electrical behavior IrO2/HZO/IrO2 device. addition, it may serve as test sample for future studies root role oxygen-vacancy interactions interface, which can influence performance instabilities HZO-based MIM structures, such wake-up, imprint, fatigue.