Simultaneously achieving high-κ and strong ferroelectricity in Hf0.5Zr0.5O2 thin film by structural stacking design
The superior dielectric and ferroelectric properties of HfO2-based thin films, coupled with excellent silicon compatibility, position them as highly attractive candidates for dynamic and ferroelectric random-access memories (DRAM and FeRAM). However, simultaneously achieving high dielectric constant...
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| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-09-01
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| Series: | Journal of Materiomics |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352847825000061 |
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| Summary: | The superior dielectric and ferroelectric properties of HfO2-based thin films, coupled with excellent silicon compatibility, position them as highly attractive candidates for dynamic and ferroelectric random-access memories (DRAM and FeRAM). However, simultaneously achieving high dielectric constant (κ) and strong ferroelectricity in HfO2-based films presents a challenge, as high-κ and ferroelectricity are associated with the tetragonal and orthorhombic phases, respectively. In this study, we report both the good ferroelectric and dielectric properties obtained in W/Hf0.5Zr0.5O2 (HZO ∼6.5 nm)/W with morphotropic phase boundary structure by optimizing stacking sequence of HfO2 and ZrO2 sublayers. Notably, by alternating stacking of 1-cycle HfO2 with 1-cycle ZrO2 sublayers ((1–HfO2)/(1–ZrO2)), high-κ (>50) and large polarization (2Pr > 40 μC/cm2, after wake-up) can be achieved. Besides, the (1–HfO2)/(1–ZrO2) stacking configuration presents better thermal stability compared to other stacking sequences. Furthermore, the incorporation of an Al2O3 layer leads to a low leakage current density (<10−7 A/cm2 at 0.65 V) and high dielectric endurance over 1013 cycles (operating voltage ∼0.5 V). A low equivalent oxide thickness (EOT ∼0.53 nm) and considerable polarization with low leakage are simultaneously achieved. These results highlight the potential of HfO2-based films with optimized structural stacking as a trade-off approach for integrating DRAM and FeRAM on one-chip. |
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| ISSN: | 2352-8478 |