Volatility
Must vaporize cleanly at accessible temperatures. TMHD achieves this through steric shielding by tert-butyl groups that prevent oligomerization.
- TMHD: Good — sublimes at 180–220 °C under vacuum
Science & applications
Metal-organic precursor science.
TMHD chemistry, deposition applications, compound-specific quality requirements and technical resources.
Precursor science
Why β-diketonates for ALD?
Every ALD precursor must balance three competing demands. Understanding where TMHD sits in this landscape is essential for process design.
The ALD precursor trilemma
No precursor optimizes all three simultaneously. TMHD maximizes thermal stability at the cost of higher deposition temperatures and the requirement for a strong oxidant.
Thermal Stability
Must survive heated delivery lines without decomposing. TMHD excels here — no β-hydrogens means no premature decomposition pathway.
- TMHD: Excellent — high stability among common ALD ligands
Reactivity
Must react with co-reactant cleanly to form the target film. TMHD requires O₃ or plasma — H₂O alone is insufficient for ligand cleavage.
- TMHD: Low — O₃ or plasma required
On smaller screens, scroll horizontally to read the complete scheme.
Ligand architecture
The chelate advantage
TMHD (2,2,6,6-tetramethyl-3,5-heptanedionate) is a β-diketonate ligand where two oxygen donors chelate the metal center. Three design features make it well-suited for high-temperature ALD.
Chelate effect
Bidentate coordination creates a thermodynamically stable six-membered ring, resisting ligand dissociation in heated delivery lines.
Steric shielding
Four tert-butyl groups surround the metal center, blocking oligomerization and supporting consistent vapor pressure across batches.
No β-hydrogens
The absence of β-hydrogens eliminates the β-hydride elimination pathway that causes premature decomposition in amide precursors above ~250 °C.
Comparison
Ligand family comparison
How β-diketonates compare with other ALD precursor chemistries. Each family trades off stability, reactivity, and integration flexibility.
| Ligand Family | Thermal Stability | Reactivity | ALD Window | Best For |
|---|---|---|---|---|
| β-Diketonates (TMHD/thd) Zr(TMHD)₄, Cu(TMHD)₂, Gd(TMHD)₃ | Excellent — no β-hydrogens to enable premature decomposition | Low — requires strong oxidants (O₃ or plasma) | 250–400 °C (precursor-dependent) | High-temperature oxide epitaxy, complex oxides (PZT, YBCO), R&D-to-pilot process development where delivery-line stability is paramount |
| Alkylamides (TDMA-class) TDMAZ, TEMAZ, TDMAH | Poor — weak M–N bonds susceptible to homolysis | Excellent — reacts with H₂O at low temperatures | 150–250 °C (narrow ceiling due to decomposition) | Low-temperature ALD (<250 °C), OLED encapsulation, perovskite interfaces. Dominant for high-volume HfO₂/ZrO₂ production ALD at leading-edge fabs |
| Amidinates & Guanidinates Cu(I) amidinates, Ru amidinates | Good — chelate ring improves stability vs amides | Good — highly reactive M–N bonds, H₂-reducible | 150–300 °C | Metallic Cu/Ru ALD at moderate temperatures, barrier-less interconnects |
| Alkoxides ZTB (Zr tert-butoxide), Ti(OiPr)₄ | Moderate | Moderate to good with H₂O | 200–350 °C | Specific oxide depositions where direct M–O is advantageous and thermal budget is moderate |
| Cyclopentadienyls (Cp) Gd(iPrCp)₃, Cp₂ZrMe₂ | Moderate — strong M–C bonds but can decompose >250 °C | Good — reactive with H₂O and O₃ | 200–365 °C (precursor-dependent) | High-GPC oxide deposition where moderate temperatures and H₂O compatibility are needed |
Technical limitations
Known limitations of TMHD precursors
Here is where TMHD is not the right choice:
High deposition temperatures
ALD windows of 250–400 °C exclude use on organic substrates, perovskite absorbers, and other temperature-sensitive layers.
Ozone or plasma required
H₂O is insufficient for TMHD ligand cleavage. Processes without O₃ or plasma capability cannot use TMHD precursors.
Carbon incorporation risk
At suboptimal temperature or insufficient O₃ dose, incomplete ligand combustion leaves carbon residues (especially for Gd at ~2.3 at.% C).
Lower GPC vs newer chemistries
0.24–0.3 Å/cycle is lower than amide-based (~1.25 Å) or Cp-based (~1.4 Å) alternatives, meaning longer cycle counts for equivalent thickness.
For low-temperature requirements, see our thermal compatibility advisory and custom synthesis capabilities.
Product portfolio
Three precursors. One platform.
All TMHD precursors share the same halide-free, thermally robust ligand architecture. Each is optimized for specific metal oxide or metallic film targets.
Zirconium (Zr)
Zirconium Tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionate)
High thermal stability minimizes decomposition risk in heated delivery lines. Halide-free — no Cl/F contamination pathway. Air-stable solid handling simplifies logistics. Well-suited for R&D and pilot-scale process development. Note: high-volume fab production ALD for ZrO₂ typically uses amide-class precursors (TDMAZ/TEMAZ) for their lower deposition temperatures and higher GPC.
- ZrO₂ (monoclinic + orthorhombic)
- PZT components
- Zr-doped dielectrics
- Dielectric constant k = 24–32
- Leakage: 3.3 × 10⁻⁶ A/cm² at 1 MV/cm
- Carbon/hydrogen <0.5 at.% in optimal ALD window
- Stoichiometric, highly crystalline films
- High-k dielectric R&D and process development (CMOS, FinFET, GAA)
- DRAM capacitor dielectric development and pilot-scale evaluation
- Solid oxide fuel cell electrolytes
- Optical coatings
- Short name
- Zr(TMHD)₄
- Formula
- C₄₄H₇₆O₈Zr
- CAS
- 18865-74-2
- Molecular weight
- 824.29 g/mol
- Purity
- ≥99.0%
- Appearance
- White to off-white crystalline powder
- Solubility
- Toluene, THF, hexane
- Storage
- Inert atmosphere, room temperature, protect from moisture
- Vaporization
- Sublimes at 180–220 °C under vacuum (~0.1–1.0 Torr). At atmospheric pressure, melts at 318–339 °C before decomposing.
- ALD window
- 375–400 °C with O₃
- Oxidant
- Ozone (O₃) required — H₂O insufficient for TMHD ligand cleavage
- GPC
- 0.24 Å/cycle (self-limiting plateau)
- MOQ
- 25 g
- Lead time
- 4 weeks
High ALD window (375–400 °C) limits use on temperature-sensitive substrates. O₃ required as oxidant. Lower GPC than amide-based Zr precursors. Amide precursors dominate high-volume ZrO₂ ALD in leading-edge fabs.
Product specificationsCopper (Cu)
Copper Bis(2,2,6,6-tetramethyl-3,5-heptanedionate)
Entirely fluorine-free — no HF byproducts that corrode reactor components and etch barrier layers (unlike Cu(hfac)₂). Oxidation-state versatility: Cu⁰, Cu₂O, or CuO tunable by co-reactant and temperature.
- Metallic Cu (via H₂ plasma or reducing agents)
- Cu₂O (via H₂O or O₃ at 80–160 °C)
- CuO (via oxidation at 250–550 °C)
- Metallic Cu resistivity: 1.78–8 µΩ·cm (thickness-dependent)
- Cu₂O: p-type, resistivity 31–83 Ω·cm, bandgap 1.99–2.41 eV
- CuO: resistivity ~16 Ω·cm, bandgap ~1.42 eV [R23], [R24]
- Excellent adhesion to TaN/TiN barrier layers
- Cu seed layers for interconnects (oxide-reduction pathway)
- Transparent p-type semiconductors (Cu₂O)
- Catalysis and sensing
- Photovoltaic hole transport layers
- Short name
- Cu(TMHD)₂
- Formula
- C₂₂H₃₈CuO₄
- CAS
- 14040-05-2
- Molecular weight
- 430.07 g/mol
- Purity
- ≥99.0%
- Appearance
- Blue crystalline powder
- Solubility
- Toluene, THF, chloroform
- Storage
- Inert atmosphere, room temperature, protect from moisture and light
- Vaporization
- Vaporizes at ~120–140 °C
- ALD window
- Not specified
- Oxidant
- Not specified
- GPC
- Not specified
- MOQ
- 25 g
- Lead time
- 4 weeks
For direct metallic Cu ALD, industry has largely moved to Cu(I) amidinates which offer higher reactivity with molecular H₂ at low temperatures. Cu(TMHD)₂ ALD is substrate/catalyst-dependent for metallic Cu.
Product specificationsGadolinium (Gd)
Gadolinium Tris(2,2,6,6-tetramethyl-3,5-heptanedionate)
Extended shelf stability under inert conditions. Strong resistance to thermal degradation in delivery lines. Preferred for demanding high-temperature environments where Cp-based alternatives may decompose.
- Gd₂O₃ (cubic C-type)
- Gd-doped HfO₂/ZrO₂
- GdScO₃
- Dielectric constant k ≈ 9–14 (ALD Gd₂O₃; up to ~20+ for ternary GdScO₃)
- Wide optical bandgap
- Amorphous below 250 °C; cubic crystalline above
- Carbon ~2.3 at.%, hydrogen ~1.7 at.% (higher than Zr)
- High-k gate dielectrics (Gd-doped HfO₂)
- SiGe channel passivation
- Rare-earth phosphors and scintillators
- Neutron detection (¹⁵⁷Gd: highest thermal neutron capture cross-section)
- Short name
- Gd(TMHD)₃
- Formula
- C₃₃H₅₇GdO₆
- CAS
- 14768-15-1
- Molecular weight
- 707.06 g/mol
- Purity
- ≥99.0%
- Appearance
- White to pale yellow crystalline powder
- Solubility
- Toluene, THF, hexane
- Storage
- Inert atmosphere, room temperature, protect from moisture
- Vaporization
- Sublimes cleanly at moderate temperatures under vacuum
- ALD window
- 250–300 °C with O₃
- Oxidant
- Ozone (O₃) required
- GPC
- ~0.3 Å/cycle
- MOQ
- 25 g
- Lead time
- 4 weeks
Higher carbon/hydrogen incorporation (~2.3/1.7 at.%) vs Zr films. Lower GPC than Cp-based Gd precursors (~1.4 Å/cycle for Gd(iPrCp)₃). Requires O₃, not H₂O.
Product specificationsApplication guide
Where TMHD precursors excel — and where they don’t
Select an application to see precursor recommendations, film performance targets, and honest assessments of where TMHD is the right choice.
High-k Gate Dielectrics
Sub-3 nm EOT with halide-free precursor chemistry
ALD ZrO₂, Gd₂O₃, and Gd-doped HfO₂ are critical high-k dielectric materials for advanced CMOS nodes (FinFET, GAA). Halide-free TMHD precursors avoid precursor-derived Cl⁻ trap formation, which can degrade charge carrier mobility and dielectric reliability.
Precursors: Zr(TMHD)₄, Gd(TMHD)₃
Key requirements
- Self-limiting ALD growth at 375–400 °C (Zr) or 250–300 °C (Gd)
- Ozone co-reactant for complete ligand combustion
- Trace metal impurities <50 ppb (industry target)
- Sub-0.5 at.% carbon in deposited films
| Property | Target | Source |
|---|---|---|
| Dielectric constant (ZrO₂) | k = 24–32 | [R2] |
| Dielectric constant (Gd₂O₃) | k ≈ 9–14 (binary oxide); k > 20 for ternary GdScO₃ | [R9], [R22], [R17] |
| Leakage current (ZrO₂) | 3.3 × 10⁻⁶ A/cm² at 1 MV/cm | [R2] |
| Carbon content | <0.5 at.% (Zr), ~2.3 at.% (Gd) | [R1], [R9] |
Why TMHD
TMHD eliminates the Cl⁻ contamination pathway inherent to halide precursors like HfCl₄/ZrCl₄ (1–3 at.% residual Cl). No HF corrosion risk (vs fluorinated alternatives). Extreme delivery-line stability prevents parasitic CVD in long heated lines.
Quality & analytical
Why purity matters at advanced nodes
At sub-5 nm technology nodes, even ppb-level contaminants shift threshold voltages, create leakage paths, and degrade device reliability. Precursor purity is not a specification — it is a yield driver.
| Contaminant | Impact on Films | Threshold | TMHD Advantage |
|---|---|---|---|
| Chloride (Cl⁻) Halide-based precursors (HfCl₄, ZrCl₄, TiCl₄) | Trapped Cl⁻ ions act as electron traps, shifting threshold voltage and degrading dielectric reliability. 1–3 at.% residual Cl typical in films from HfCl₄ at ~300 °C. | ≤10 ppm in precursor (electronic grade target) | TMHD ligands contain no halogen atoms, avoiding precursor-derived Cl contamination at the molecular level rather than managing it through post-deposition anneal. [R11] |
| Fluorine (F⁻) Fluorinated precursors (Cu(hfac)₂, HFIP-based) | HF byproduct corrodes reactor walls, etches TaN/TiN barrier layers, and embeds F⁻ as charge traps in gate dielectrics. | Zero (not present in TMHD chemistry) | Cu(TMHD)₂ is a fluorine-free Cu(II) precursor for ALD/CVD, avoiding the HF byproducts associated with fluorinated alternatives. [R5] |
| Carbon (C) Incomplete ligand combustion during ALD | Residual C creates leakage paths in dielectric films and increases resistivity in metallic films. Acceptable levels depend on film function. | <0.5 at.% (Zr, optimal), <3 at.% (Gd, typical) | O₃ as co-reactant combusts TMHD ligands more completely than H₂O-based processes. Carbon is minimized within the verified ALD window. [R1], [R9] |
| Trace metals Precursor synthesis impurities, metal exchange | Even ppb-level contamination at advanced nodes can shift electrical properties. Particularly critical for DRAM and CMOS high-k. | <50 ppb total metals (electronic grade target) | Sublimation purification of TMHD compounds provides an inherent secondary purification step. Solid handling avoids liquid-phase metal exchange. [R4], [R19] |
| Moisture (H₂O) Precursor storage and handling | Premature hydrolysis degrades precursor performance and causes particulate formation in delivery systems. | <100 ppm by Karl Fischer | TMHD solids are more air-stable than liquid amide or alkoxide precursors, reducing hydrolysis risk during handling and transport. [R4], [R5] |
Halide-free chemistry
The halide-free advantage
Carbon contamination management
Carbon incorporation is the primary contamination concern for TMHD-based ALD. With proper process optimization, it is manageable:
ZrO₂ (Optimal)
C and H by TOF-ERDA at 375–400 °C with O₃
- <0.5 at.%
Gd₂O₃ (Typical)
Higher due to larger ligand:metal ratio. ~1.7 at.% H.
- ~2.3 at.% C
Mitigation
Adequate temperature within ALD window + sufficient O₃ pulse duration. Extended purge to remove byproducts.
Specification targets
Electronic-grade purity targets
Industry-standard specifications that Mironova targets for electronic-grade precursors.
| Parameter | Target | Note |
|---|---|---|
| Assay purity | ≥99.0% | By NMR or titration. Standard for research-grade metal-organic precursors. |
| Trace metals | <50 ppb total | Typical electronic-grade target. Verified by ICP-MS. |
| Halide content | ≤10 ppm (Cl⁻) | TMHD synthesis is inherently halide-free. Target reflects trace contamination limits. |
| Residual moisture | <100 ppm | Measured by Karl Fischer titration. Critical for delivery system compatibility. |
| Non-volatile residue | <0.1% by weight | TGA confirms complete sublimation/evaporation. Prevents buildup in delivery lines. |
Methods
Analytical capabilities
ICP-MS
Trace metal impurities at ppb and sub-ppb levels
- Inductively Coupled Plasma Mass Spectrometry
- Confirms trace metal content meets <50 ppb electronic-grade targets
TGA/DSC
Mass loss vs temperature, phase transitions, decomposition onset
- Thermogravimetric Analysis / Differential Scanning Calorimetry
- Validates sublimation profile, thermal stability window, and absence of non-volatile residue
NMR
¹H and ¹³C spectra confirming ligand environment and coordination
- Nuclear Magnetic Resonance Spectroscopy
- Verifies molecular structure, chelation integrity, and absence of free ligand or hydrolysis products
Karl Fischer
Residual moisture content in ppm
- Karl Fischer Titration
- Confirms moisture levels below specification to prevent hydrolysis in delivery systems
XRD
Crystalline phase identification and purity
- X-ray Diffraction
- Confirms expected crystal structure and absence of secondary phases
Mironova capability
Any metal. Engineered ligand. To spec.
When off-the-shelf precursors don't match your process window, we design and synthesize custom metal-organic compounds tailored to your deposition requirements.
Ligand Engineering
β-Diketonates, amides, amidinates, guanidinates, alkoxides, and cyclopentadienyl derivatives. Homoleptic or heteroleptic architectures with tuned volatility, reactivity, and thermal stability.
Air-Sensitive Chemistry
Full Schlenk-line and glovebox capabilities for pyrophoric and moisture-sensitive precursors. Inert-atmosphere synthesis, purification, and packaging.
Heteroleptic Design
Mixed-ligand precursors that combine the thermal stability of one ligand class with the reactivity of another. Tailored to your specific process window.
Sublimation Purification
Vacuum sublimation for electronic-grade final purification. Removes trace metals and non-volatile residues below ICP-MS detection limits.
NDA & IP Protection
Full NDA framework for novel precursor development. Your proprietary chemistry stays confidential through synthesis, characterization, and delivery.
~4-Week Lead Time
From specification to characterized product. 25 g minimum order for R&D evaluation, scaling to kg+ for process qualification.
Expanding metal portfolio
Beyond Zr, Cu, and Gd, we are building synthesis capabilities for next-generation interconnect and barrier metals driven by leading-edge semiconductor demand.
Ruthenium (Ru)
Barrier-less interconnects for sub-10 nm nodes. Ru ALD using amidinates achieves ~10 µΩ·cm. Growing demand from leading-edge foundries. [R16]
Molybdenum (Mo)
Emerging contact metal for GAA transistors. Mo fills narrow contact trenches with lower resistivity than W at small dimensions.
Cobalt (Co)
Via fill and barrier applications at advanced nodes. Co ALD is increasingly adopted where Cu electromigration is a concern.
Mironova capability
Domestic supply for critical materials
Mironova provides US-manufactured precursors with full batch traceability and provenance documentation.
US Manufacturing & Domestic Sourcing
All TMHD precursors synthesized and purified at our Fairfield, NJ facility. No dependency on overseas toll manufacturing, no China-linked intermediates. Full chain-of-custody from raw materials to packaged precursor — meeting the domestic sourcing expectations that CHIPS-funded fabs require from their supply chain.
Fairfield, NJ
CHIPS Act Supply-Chain Readiness
The CHIPS and Science Act (2022) allocates $39B for domestic semiconductor manufacturing and $11B for R&D. While the Act does not mandate domestic precursor sourcing directly, CHIPS funding recipients must demonstrate supply chain traceability, provenance documentation, and compliance with national security guardrails — all of which flow down to chemical suppliers. Mironova provides batch-level traceability, raw material sourcing transparency, and full COA documentation aligned with these requirements.
Strategic Supply Chain Value
Most specialty metal precursors are concentrated in Asia, creating single-source risk for fab operations. The CHIPS Act is driving demand for domestic, trusted suppliers — even for niche reagents. US-manufactured precursors with full provenance documentation are not just procurement-convenient; they are strategically valuable to fabs building CHIPS-ready supply ecosystems.
Market Context
The ALD/CVD precursor market is estimated at $1.2–1.9B (2024) with 6.5–10% CAGR through 2029–2032. High-k dielectric precursors (Zr, Hf, rare-earth) are among the steepest growth segments, driven by GAA transistor adoption and advanced DRAM. [M1]
Resources
Technical guides & process data
Engineer-facing resources for evaluating and integrating TMHD precursors into your ALD/CVD workflows. Literature-backed protocols, characterization checklists, and comparison data.
ALD Deposition Protocols
Substrate preparation, delivery parameters, reactor conditions, and growth metrics for each TMHD precursor. Designed for research-scale cross-flow and showerhead reactors.
Precursor Handling & Delivery Guide
Practical guidelines for integrating TMHD precursors into ALD toolsets, including thermal management, bubbler and DLI delivery, and degradation detection.
Film Characterization Checklist
Step-by-step characterization checklist covering thickness, uniformity, composition, crystallinity, and interface quality for TMHD-derived films.
Troubleshooting Guide for TMHD-Based ALD
Problem-cause-solution format covering low GPC, CVD contamination, carbon incorporation, and uniformity issues specific to sterically bulky TMHD precursors.
TMHD vs Alternative Precursors
Side-by-side comparison tables for Zr, Cu, and Gd precursors covering ALD windows, GPC, contamination, and key limitations to guide precursor selection.
Application-Specific Process Notes
Expert guidance for implementing TMHD-derived thin films across critical semiconductor and photonics applications, with emphasis on integration constraints.
Technical inquiry
Discuss your precursor requirements
Whether you need one of our catalog TMHD precursors or a custom molecule, share your deposition requirements with our chemistry team.
Technical Consultation
Our chemistry team evaluates your process requirements and recommends optimal precursor chemistry, delivery conditions, and co-reactant selection.
NDA Protection
Full confidentiality framework for proprietary processes. Your chemistry and integration details stay protected.
~4 Week Lead Time
From specification to characterized product. 25 g minimum for R&D, scaling to kg+ for process qualification.
References
Literature & sources
Technical claims retain their source context and limitations. DOIs are supplied where available.
Zirconia Thin Films by Atomic Layer Epitaxy: A Comparative Study on the Use of Novel Precursors with Ozone
Putkonen M, Niinistö J, Kukli K, et al.
Zr(thd)₄/O₃ ALD window at 375–400 °C, GPC 0.24 Å/cycle, monoclinic ZrO₂ with <0.5 at.% C and H impurities by TOF-ERDA.
DOI 10.1039/B105272CAtomic Layer Deposition of ZrO₂ Thin Films Using Zr(thd)₄ and Ozone
Niinistö J, et al.
Confirms self-limiting growth plateau at 375–400 °C with 0.24 Å/cycle GPC. ZrO₂ films exhibit k = 24–32 and leakage of 3.3 × 10⁻⁶ A/cm² at 1 MV/cm.
Structure and Dielectric Property of High-k ZrO₂ Films Grown by ALD Using TDMAZ and Ozone
Liu J, Li J, et al.
TDMAZ+O₃ ALD window 200–250 °C with higher GPC (~1.25 Å/cycle), but suffers severe thermal decomposition above 250 °C causing parasitic CVD.
DOI 10.1186/s11671-019-2989-8Vapour Pressure and Heat Capacities of Metal Organic Precursors: Y(thd)₃ and Zr(thd)₄
Fulem M, Růžička K, et al.
Peer-reviewed vapor pressure measurements for Zr(thd)₄. Sublimation enthalpy 85.36 ± 3.60 kJ/mol. Sublimes effectively at 180–220 °C under vacuum (~0.1–1.0 Torr).
DOI 10.1016/j.jcrysgro.2003.12.016Trends in Copper Precursor Development for CVD and ALD Applications
Gordon PG, Kurek A, Barry ST
Comprehensive review of Cu precursors. Cu(thd)₂ is fluorine-free (vs Cu(hfac)₂ HF corrosion), but industry trending toward Cu(I) amidinates for low-T metallic Cu ALD.
Growth of (111)-Textured Copper Thin Films by Atomic Layer Deposition
Mane AU, Shivashankar SA
Cu(thd)₂ ALD using H₂ reduction yields highly textured Cu films. Vaporization at ~120–140 °C. Process is substrate/catalyst-dependent.
DOI 10.1016/j.jcrysgro.2004.11.143Atomic Layer Chemical Vapour Deposition of Copper
Mane AU, Shivashankar SA
Cu resistivities from ~4.25 µΩ·cm (20 nm) to ~1.78 µΩ·cm (120 nm) with excellent adhesion on TiN/TaN at 300 °C.
DOI 10.1016/j.mssp.2004.09.094A Low Temperature Growth of Cu₂O Thin Films as Hole Transporting Material for Perovskite Solar Cells
Pellegrino AL, Lo Presti F, et al.
Cu₂O from Cu(tmhd)₂ MOCVD: phase-pure p-type, stabilized at 250 °C. Resistivity 31–83 Ω·cm, bandgap 1.99–2.41 eV. CuO at higher temperatures.
DOI 10.3390/ma15217790Gadolinium Oxide Thin Films by Atomic Layer Deposition
Niinistö J, Petrova N, et al.
Gd(thd)₃/O₃ ALD: self-limiting at ~300 °C, GPC ~0.3 Å/cycle. Film impurities: ~2.3 at.% C, ~1.7 at.% H. Cubic C-type Gd₂O₃ above 250 °C.
DOI 10.1016/j.jcrysgro.2005.08.002Plasma-Enhanced Atomic Layer Deposition and Etching of High-k Gadolinium Oxide
Vitale SA, et al.
PE-ALD using Gd(iPrCp)₃ + O₂ plasma: higher GPC (~1.4 Å/cycle at 250 °C) but narrower window and moisture sensitivity compared to Gd(thd)₃.
DOI 10.1116/1.3664756Chlorine Contamination in HfO₂ Films Deposited by ALD Using HfCl₄
Park PK, Kang S-W, et al.
HfCl₄/H₂O ALD leaves 1–3 at.% residual Cl at ~300 °C, acting as electron traps that degrade dielectric performance. Halide-free precursors eliminate this.
DOI 10.1021/acs.jpcc.5b05286Common Precursors and Surface Mechanisms for Atomic Layer Deposition
Winter CH, et al.
Comprehensive review of ALD precursor chemistry families, surface mechanisms, and ligand design principles for next-generation deposition processes.
Thin Film Encapsulation for Organic Light Emitting Diodes by ALD
Meyer J, et al.
ALD Al₂O₃/ZrO₂ nanolaminates achieve WVTR <10⁻⁶ g/m²/day for OLED encapsulation. Requires low-temperature (<100 °C) ALD — incompatible with TMHD precursors.
DOI 10.1002/adma.200803440All-Perovskite Tandem Solar Cells with ALD SnOₓ Electron Transport Layer
Johnson B, et al.
ALD SnOₓ on fullerenes with in-situ O₃ functionalization enables >24% efficiency perovskite tandems. Perovskite degrades above ~150 °C — TMHD incompatible for direct deposition.
DOI 10.1016/j.joule.2023.10.009Low Temperature Growth of High Purity, Low Resistivity Copper Films by Atomic Layer Deposition
Knisley TJ, et al.
Low-temperature Cu ALD using Cu(I) amidinate achieves high-purity metallic Cu with molecular H₂, demonstrating the newer precursor class that has partially displaced Cu(thd)₂ for metallic Cu.
DOI 10.1021/cm202475eAtomic Layer Deposition of Ruthenium Using Bis(N,N′-di-tert-butylacetamidinato)ruthenium(II) Dicarbonyl and NH₃
Li H, et al.
Ru amidinate ALD achieves ~10 µΩ·cm resistivity, approaching bulk Ru. Demonstrates barrier-less Ru interconnect potential for sub-10 nm nodes.
DOI 10.1149/1.2789294Gadolinium Scandate: Next Candidate for Alternative Gate Dielectric in CMOS Technology?
Fröhlich K, Fedor J, Kostič I, Maňka J, Ballo P
MOCVD GdScO₃ at 600 °C maintains amorphous phase through 1000 °C RTA, preventing grain boundary leakage. k > 20 for the ternary scandate (GdScO₃), not binary Gd₂O₃. Validates Gd-based ternary high-k dielectrics for advanced nodes.
DOI 10.2478/v10187-011-0009-zEmerging Applications of Atomic Layer Deposition for Lithium-Ion Battery Materials
Meng X, et al.
Review of ALD for conformal electrode coatings and solid electrolytes. Ultra-high precursor purity is critical for electrochemical stability and long-term cycling.
DOI 10.1002/adma.201200397Substituent Effects on the Volatility of Metal β-Diketonates
Fahlman BD, Barron AR
Systematic study of substituent effects on β-diketonate volatility. tert-Butyl groups (TMHD) maximize steric shielding, prevent oligomerization, and enhance vapor pressure.
DOI 10.1002/1099-0712(200005/10)10:3/5<223::AID-AMO411>3.0.CO;2-MRealization of Thin Film Encapsulation by ALD of Al₂O₃ at Low Temperature
Yang Y-Q, Duan Y, et al.
WVTR of ~8.7×10⁻⁶ g/m²/day achieved with O₃-based Al₂O₃ ALD at 80 °C. Confirms low-temperature ALD requirement for OLED — TMHD precursors excluded.
DOI 10.1021/jp406738hAtomic Layer Deposition of Ru in nanoTSV with High Coverage and Low Resistivity
Chen Z, et al.
ALD Ru with ~15 µΩ·cm resistivity in nano-TSV structures, demonstrating strategic Ru interconnect momentum for next-generation nodes.
DOI 10.1039/D5NA00051CALD of Rare Earth Oxide Thin Films from β-Diketonate Precursors
Päiväsaari J, Putkonen M, Niinistö L
ALD of Ln₂O₃ (Ln = La, Pr, Nd, Gd) from Ln(thd)₃/O₃. Measured dielectric constants for binary Ln₂O₃ films: k = 8.4–11.1 across the series. Gd(thd)₃/O₃ yields k ≈ 9–13, significantly lower than the k > 20 values reported for the ternary GdScO₃.
DOI 10.1016/j.tsf.2004.06.160Copper Oxide Thin Films Prepared by Chemical Vapor Deposition from Copper Dipivaloylmethanate
Maruyama T
CuO films by thermal CVD from Cu(DPM)₂ (= Cu(TMHD)₂) at 350–550 °C. Reports resistivity ~16 Ω·cm and bandgap ~1.42 eV for CuO films, consistent with subsequent studies.
DOI 10.1143/JJAP.37.4099Growth and Characterization of CuO Thin Films Grown by Chemical Spray Pyrolysis
Zhang Q, Zhang K, Xu D, Yang G, Huang H, Nie F, Liu C, Yang S
CuO films with resistivity in the range of 10–30 Ω·cm and bandgap 1.3–1.5 eV, corroborating the Cu(TMHD)₂-derived CuO values from Maruyama 1998.
Gd-Doped ZrO₂ as a High-k DRAM Capacitor Dielectric with Reduced Leakage via p-Type Acceptor Mechanism
Lee J, et al.
Gd doping in ZrO₂ achieves EOT of 0.76 nm with improved leakage characteristics via a p-type acceptor mechanism. Provides the strongest published argument for Gd(TMHD)₃ as a demand vector in advanced DRAM capacitor dielectrics.
Superlattice HfO₂–ZrO₂ Films with Ultrahigh Dielectric Constant
Yao Y, et al.
SL-Hf₀.₃Zr₀.₇O₂ superlattice films achieve dielectric constant k ≈ 59, far exceeding binary HfO₂ or ZrO₂. Strengthens the narrative for Zr-based precursors in next-generation ferroelectric and superlattice architectures.
ALD/CVD Precursor Market Outlook
TECHCET
ALD/CVD precursor market ~$1.2–1.9B in 2024 with 6.5–10% CAGR through 2029–2032. High-k dielectric segment (Zr, Hf, rare-earth) is among the steepest growth trajectories.
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TMHD Precursors for Semiconductor ALD/CVD
US-manufactured, halide-free, CHIPS Act supply-chain ready
TMHD Precursors for Optical Coatings
High-purity halide-free oxide deposition for AR and filter coatings
TMHD Precursors for Battery & Energy Applications
Halide-free cathode coatings for cycling stability
FAQ
Frequently asked questions.
What are TMHD precursors used for?
TMHD (2,2,6,6-tetramethyl-3,5-heptanedionate) precursors are used in atomic layer deposition (ALD) and chemical vapor deposition (CVD) to deposit high-quality metal oxide thin films such as ZrO₂, Cu, and Gd₂O₃ for semiconductor devices, DRAM capacitors, and optical coatings.
Why are halide-free precursors important for ALD?
Halide-free precursors eliminate Cl and F contamination pathways at the molecular level. Halide impurities in thin films create charge traps that degrade dielectric performance, reduce breakdown voltage, and lower device reliability. TMHD precursors provide a fundamentally halide-free chemistry platform.
What is the ALD window for Zr(TMHD)₄?
Zr(TMHD)₄ has a self-limiting ALD window of 375–400 °C with O₃ as oxidant, achieving a growth per cycle (GPC) of approximately 0.24 Å/cycle. The higher deposition temperature reflects the thermal stability of the TMHD ligand framework.
How do Mironova Labs precursors fit into CHIPS Act supply chains?
CHIPS-funded fabs must demonstrate supply chain traceability, domestic sourcing preference, and compliance with national security guardrails — requirements that flow down to chemical suppliers. Mironova manufactures all TMHD precursors at our Fairfield, NJ facility with no China-linked intermediates, full batch-level traceability, raw material provenance documentation, and comprehensive COA packages. This positions Mironova as a CHIPS Act supply-chain ready supplier that simplifies procurement compliance for funded projects.
What purity levels are available for metal-organic precursors?
Mironova Labs targets ≥99.0% purity for all TMHD precursors, verified by ICP-MS trace metal analysis, TGA/DSC thermal profiling, and NMR structural confirmation. Custom electronic-grade specifications with ppb-level impurity targets are available.
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Product Catalog
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TMHD Precursors for Semiconductor ALD/CVD
US-manufactured, halide-free, CHIPS Act supply-chain ready
TMHD Precursors for Optical Coatings
High-purity halide-free oxide deposition for AR and filter coatings
TMHD Precursors for Battery & Energy Applications
Halide-free cathode coatings for cycling stability