Effect of Kr/O₂-Plasma Reactive Sputtering on Ferroelectric Nondoped HfO₂ Formation for MFSFET With Pt Gate Electrode

Fabrication Strategies of Metal–Ferroelectric–Insulator–Silicon Gate Stacks Using Ferroelectric Hf–Zr–O and High-k HfO2 Insulator Layers for Securing Robust Ferroelectric Memory Characteristics

“…Thus, it was simply expected that H3 employing a 40 nm thick HZO FL exhibited the best performance of NVM operations for the MFIS devices. However, the obtained MW values rather decreased from 1.8 to 1.4 V with increasing FL thickness from 20 (H1) to 40 nm (H3), which was suggested to result from the degradation of IL quality owing to plausible plasma damage during the sputtering deposition of HZO . In other words, the charge injection phenomenon might be more dominantly influenced by plasma-damaged ILs with increasing HZO FL thickness, resulting in the degradation of ferroelectric MW in C – V curves.…”

“…However, the obtained MW values rather decreased from 1.8 to 1.4 V with increasing FL thickness from 20 (H1) to 40 nm (H3), which was suggested to result from the degradation of IL quality owing to plausible plasma damage during the sputtering deposition of HZO. 63 In other words, the charge injection phenomenon might be more dominantly influenced by plasma-damaged ILs with increasing HZO FL thickness, resulting in the degradation of ferroelectric MW in C−V curves. Furthermore, Ryu et al reported the degradation of ferroelectricity with the increase in film thickness of the HZO FL deposited with the sputtering method owing to the unintended stabilization of the nonferroelectric m-phase, 55 which was expected to induce a longer switching time for polarization reversal and a higher activation energy for the ferroelectric switching dynamics.…”

Ferroelectric Hafnium Nitride Thin Films Directly Formed on Si(100) Substrate

“…This is attributed to the effect of strain of the gate electrode on the metastable phase formation which is similar to the ferroelectric HfO2 with metastable phase [17], [18]. It is considered that the crystallization of HfN1.15 was enhanced by the PMA process which is similar to the ferroelectric HfO2 thin film formation [18]. The HfN film with ferroelectric phase might also be formed on the metal substrate such as TiN similar to the ferroelectric HfO2 thin film formation.…”

“…HE ferroelectric HfO2 thin film has much attention for the Metal-Ferroelectrics-Si Field-Effect Transistor (MFSFET) nonvolatile memory (NVM) applications because of its Si compatibility [1]- [13]. One of the issues of the ferroelectric HfO2 is the SiO2 interfacial layer (IL) formation during the deposition and/or post-annealing processes which induces the depolarization field and degrades the memory device characteristics not only for ferroelectric doped HfO2 but for nondoped HfO2 [14]- [18]. In case of the ferroelectric HfO2, a few nanometer thick SiO2 IL is formed which will degrade the memory characteristics.…”

“…The HfNx (x>1.0) has some crystalline phases such as cubic phase (c-Hf3N4) and rhombohedral phase (-HfNx) [31]. Although the Hf-N system does not have a noncentrosymmetric crystal structure, the strained rhombohedral phase might show the ferroelectric properties similar to the ferroelectric HfO2 with rhombohedral phase [18], [32], [33]. In this paper, we have investigated the ferroelectric HfNx thin film formation on the Si(100) substrate for the MFSFET-type NVM applications.…”