Hafnium Oxide, HfO2
Hafnium oxide (HfO2) is a refractory, wide-bandgap ceramic oxide and the industry-standard high-k gate dielectric in advanced CMOS logic manufacturing. Infinita Materials supplies HfO2 sputtering targets in hot-pressed and sintered ceramic form across standard and custom geometries, engineered for stoichiometric, low-defect thin-film deposition. These targets serve semiconductor fabs, optical coating houses, and ferroelectric memory research groups requiring tightly controlled film composition. All targets are supplied by Infinita Materials with full traceability to purity and process documentation.
| Purity (%) : | >99.9 |
| Dimensions : | Dia. 1”, Thick. 0.125” Dia. 2”, Thick. 0.25” |
Introduction to Hafnium Oxide
Hafnium oxide (HfO₂) is a refractory ceramic that crystallises in the monoclinic baddeleyite structure at room temperature and transforms to tetragonal and cubic phases at elevated temperatures. It is a wide-bandgap electrical insulator with a dielectric constant of approximately 20–25 and a melting point above 2,750 °C, providing excellent thermal, chemical, and oxidation resistance. These properties make HfO₂ a leading high-k dielectric for advanced semiconductor devices. As a sputtering target, dense ceramic HfO₂ enables precise stoichiometry, uniform thickness, and reproducible deposition. Sputtered films are widely used in gate dielectrics, optical coatings, protective layers, and emerging ferroelectric HfO₂ and HZO memory devices.
FAQs
Introduction to Hafnium Oxide
Hafnium oxide (HfO₂) is a refractory ceramic that crystallises in the monoclinic baddeleyite structure at room temperature and transforms to tetragonal and cubic phases at elevated temperatures. It is a wide-bandgap electrical insulator with a dielectric constant of approximately 20–25 and a melting point above 2,750 °C, providing excellent thermal, chemical, and oxidation resistance. These properties make HfO₂ a leading high-k dielectric for advanced semiconductor devices. As a sputtering target, dense ceramic HfO₂ enables precise stoichiometry, uniform thickness, and reproducible deposition. Sputtered films are widely used in gate dielectrics, optical coatings, protective layers, and emerging ferroelectric HfO₂ and HZO memory devices.
Key Properties of Hafnium Oxide
| Property | Value | Significance |
|---|
| Chemical formula | HfO2 | Confirms stoichiometric binary hafnia composition used for deposition-rate and mass-balance calculations |
| CAS number | 12055-23-1 | Unique registry identifier for procurement, safety documentation, and regulatory compliance |
| Molar mass | ~210.49 g/mol | Basis for stoichiometric verification and sputter-rate to mass-loss conversions |
| Density (bulk ceramic) | ~9.68 g/cm3 | Among the densest oxide sputtering targets, supporting efficient sputter yield and target longevity |
| Crystal structure | Monoclinic (baddeleyite) at room temperature; tetragonal and cubic above ~1720 C and ~2600 C | Polymorphism and strain sensitivity at thin-film scale underlie ferroelectric HZO device behaviour |
| Melting point | ~2758-2900 C (source and grade dependent) | Reflects strong Hf-O bond energy and refractory stability under sustained plasma heating |
| Band gap | ~5.7-5.8 eV | Wide electronic barrier height suppresses tunnelling leakage in nanoscale gate dielectric stacks |
| Dielectric constant (k, bulk) | ~20-25 | Roughly five to six times that of SiO2 (k~3.9), enabling equivalent capacitance at greater physical film thickness |
Types & Grades of Hafnium Oxide
Hafnium Oxide targets are offered in standard catalogue sizes and grades, with custom purity, density, and geometry available for OEM and R&D deposition systems.
| Grade / Form | Typical Purity | Key Features / Uses |
|---|
| 2N5-3N hot-pressed disc | 99.5% – 99.9% | Cost-effective grade for general optical coatings, barrier layers, and early-stage process development |
| 4N sintered ceramic target | 99.99% | Standard grade for high-k gate dielectric research and semiconductor pilot-line deposition |
| 5N ultra-high-purity target | 99.999% | Lowest metallic and particulate contamination for advanced CMOS logic and low-defect-density films |
| Rotary/cylindrical target | 99.9% – 99.99% | Extended-life format for high-throughput in-line coaters used in architectural and display glass |
| Bonded/segmented planar target | 99.9% – 99.99% | Crack-resistant indium- or elastomer-bonded mounting for large-area magnetron systems using brittle ceramic tiles |
Applications of Hafnium Oxide
Sputtered films of Hafnium Oxide support demanding roles across research and production applications where this material’s specific structural, electronic, or optical properties are the key requirement.
| Industry | Application | Function |
|---|
| Semiconductor logic | High-k gate dielectric in advanced CMOS transistors | Replaces SiO2 to suppress gate leakage current while preserving or increasing effective gate capacitance |
| Semiconductor memory | Ferroelectric HfO2 and HfZrO2 (HZO) memory (FeRAM, FeFET) | Doped and strained HfO2 thin films provide non-volatile polarisation switching at CMOS-compatible scale |
| Precision optics | Anti-reflective and high-reflectivity multilayer coatings | High refractive index (~2.0-2.1) layer alternated with low-index oxides to tune reflectance and transmission, bands |
| DRAM and passive components | High-k dielectric in MIM and MIS capacitor stacks | Increases capacitance density as memory cell footprints continue to shrink |
| Laser and protective optics | Hard, UV-transparent optical coatings | Combines wide-bandgap transparency with chemical and thermal durability for demanding optical environments |
| Displays and photovoltaics | Barrier and passivation layers in TFT and solar cell stacks | Provides a moisture and oxygen diffusion barrier alongside dielectric passivation |
Why Partner with Infinita Materials?
- Technical Depth: in-house quality control with ICP-MS and XRF purity verification, density measurement, and full certificates of analysis on every target.
- Global Logistics: reliable supply from single R&D-scale targets to production-line volumes, with established international shipping.
- Responsive Support: direct access to materials engineers for grade, bonding, and geometry selection, and process-compatibility questions.
Take the Next Step
Infinita Materials fabricates Hafnium Oxide sputtering targets engineered to the purity, density, and geometry your deposition process requires. Whether the requirement is a standard catalogue target or a custom size, purity, or bonded assembly, our team can help match the right specification to your deposition system. Request a quote or speak with our technical team to discuss your target specification.
Frequently Asked Questions
How is HfO₂ sputtered onto substrates?
Hafnium oxide is sputtered using DC or RF sputtering techniques in a vacuum environment, depending on the target and substrate material, to create uniform thin films.
Hafnium Oxide, HfO2
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