Aluminum Etchant - electronic grade

Cat. No.: A1511715

GRADE & PURITY Electronic grade

Storage

Room temperature

Shipped In

Normal

Vue d’ensemble

This etching solution is a core acidic etching system for etching aluminum and aluminum alloys (Al, Al-Si, Al-Cu, etc.) in the fields of semiconductors/microelectronics and display panels. It is also known as a phosphoric acid-nitric acid-acetic acid etching solution. Through the synergistic effects of phosphoric acid complexation, nitric acid oxidation, and acetic acid dissolution assistance, it achieves controllable, uniform isotropic/micro-anisotropic etching. It has good compatibility with photoresists and is widely suitable for wafer-level metal wiring, display panel gate/source-drain aluminum film etching, and other scenarios;

Specifications

Spécifications et pureté

electronic grade

Conditions de stockage de stockage

Room temperature

Expédié en

Normal

Grade

Qualité électronique

Application Protocols

No item-specific, validated application protocols are provided in the Product Data. Refer to your facility’s process of record (POR) and the product SDS/CoA. The following general workflow is provided for context (literature; not item-specific):

• Pre-clean: Remove organics and particulates from the wafer/substrate (e.g., solvent clean, O2 plasma) to ensure uniform wetting.
• Masking: Apply and pattern a compatible photoresist or hard mask. Soft/PEB bake per resist datasheet.
• Etch: Immerse or spray process in Aluminum Etchant at a validated temperature with agitation. Use time–temperature calibration from coupons.
• Quench and rinse: Immediate DI water quench followed by cascading rinses to remove residues and arrest reaction.
• Dry: Spin or IPA displacement/Marangoni dry to minimize watermarking and corrosion.
• Post-etch strip: Remove PR if required using a compatible stripper; confirm no adverse interaction with remaining stack.

Critical controls:

• Track bath age and contaminants; replace per control charts.
• Maintain temperature and agitation uniformity; monitor etch rate via witness samples.
• Employ appropriate materials of construction (PTFE/PFA tanks, compatible tubing).

These steps are illustrative only. Implement changes through your change-control system and EHS review.

Biological Roles

Not applicable. Aluminum Etchant is an engineered materials-processing reagent used for wet etching of aluminum and aluminum alloys. It has no biological role or metabolic function. For research and fabrication use only. See Reaction & Applications and Synthetic Utility for relevant technical details.

Buffer Applications

Not applicable. This product is not a buffering agent and is not intended for preparing biochemical buffers or maintaining pH in biological systems. If pH control is required during post-etch neutralization or waste treatment, use appropriate laboratory acids/bases with validated protocols and monitoring. Refer to Safety & Handling for cautions regarding neutralization and waste.

Green Alternatives

While aluminum etchants are inherently reactive and often corrosive, process choices can reduce environmental and EHS burdens. The following are general, literature-based comparisons and are not item-specific specifications.

Comparison considerations:

• Oxidizer content: Acidic etchants containing nitric acid present oxidizing hazards and potential NOx emissions. Alternatives with reduced or no nitric content can lower acute hazards and off-gassing, but may etch more slowly or require higher temperature/agitation.
• Alkalinity vs. acidity: Alkaline NaOH/KOH systems avoid oxidizers but generate hydrogen gas and high-pH waste; they typically show poorer PR selectivity and rougher finishes.
• Additives: Surfactant/wetting agent use can lower temperature requirements and improve uniformity, potentially reducing energy use; verify cleanroom compatibility and rinse-ability.
• Closed-loop and life extension: Inline filtration, drag-out reduction, and bath life monitoring decrease waste volumes irrespective of chemistry.

Illustrative comparison (literature, not item-specific):

• Nitric-containing phosphoric/acetic mixes: Fast, smooth Al etch; potential NOx, oxidizer hazards; good PR compatibility.
• Nitric-free phosphoric mixes or persulfate-based systems: Lower oxidizer hazard profile; may require higher temperature/longer times; different residue risks.
• Alkaline NaOH/KOH: Simple, inexpensive; significant hydrogen evolution; poor selectivity; challenging waste neutralization due to high pH and dissolved aluminate.

Greener practice tips:

• Optimize temperature to the minimum that meets throughput.
• Implement DI cascade rinses and reclaim where feasible.
• Segregate waste streams to improve treatability and reduce neutralization reagents.

Pharmaceutical Uses

Not applicable as a pharmaceutical ingredient. Aluminum Etchant is a microfabrication/materials-processing reagent and is not intended for drug formulation, excipient use, or any clinical application. For research use only, as specified. If you require pharmacopeial-grade acids/bases for regulated applications, consult relevant pharmacopeias and suppliers for conforming materials.

Physical Properties

Item-specific physical constants are not provided in the Product Data for this formulated etchant.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Density: Not specified for this item; refer to CoA/Spec Sheet.
• pH: Not specified for this item; refer to CoA/Spec Sheet.
• Refractive index, conductivity, viscosity: Not specified for this item; refer to CoA/Spec Sheet.
• Boiling/Freezing point: Not specified for this item; refer to CoA/Spec Sheet.
• Solubility: Generally fully miscible in water for most aqueous etchants (literature, composition-dependent); item-specific miscibility not specified.

Literature context (not item-specific):

• Acidic Al etchants based on concentrated phosphoric acid typically exhibit high viscosity and densities >1.3 g/mL at room temperature; boiling points depend on water content and may exceed 100 C due to non-ideal solution behavior.
• Alkaline etchants (e.g., 1–5 M NaOH) present high pH (>13) and water-like viscosities; density slightly above 1.00 g/mL depending on concentration.
• Etch rates are highly sensitive to temperature, alloying elements (Cu, Si), oxide condition, agitation, and water content. Typical wet etch rates for sputtered Al can span tens to hundreds of nm/min at 20–50 C (literature, strongly formulation- and process-dependent).

Use these literature values only as general context. For process control, rely exclusively on the lot-specific CoA/Spec Sheet and in-house calibration/monitoring.

Quality and Grades

• Grade: Electronic grade (as provided in Product Data).

What electronic grade typically implies (general guidance; not item-specific specifications):

• Low particulate burden and microelectronic cleanliness to minimize defectivity in wet benches and lithography lines.
• Tight control of ionic/metallic contaminants (e.g., alkali/alkaline earth and transition metals) to reduce dopant/defect introduction on wafers. Specific impurity limits are NOT provided here; Not specified for this item; refer to CoA/Spec Sheet.
• Batch-to-batch consistency in etch performance (rate, uniformity) through controlled formulation and filtration.
• Packaging in cleanroom-compatible containers, often pre-cleaned and double-bagged; details Not specified for this item.

How to use this information:

• For wafer-level processes, request the lot CoA for trace metals, anion/cation profile, particle counts, and filtration grade. Verify compatibility with your photoresist, hard masks (SiO2/Si3N4), and underlying stacks via incoming QC.
• If your application is analytical or research-only, the same low-contamination attributes may assist in reproducible surface finish and minimized residue.

Stabilizers or inhibitors: Not specified for this item; refer to CoA/Spec Sheet. If inhibitors/wetting agents are present in some formulations (literature), they can influence undercut and wetting; validate in your process window.

Reaction and Applications

Primary application: wet etching and pattern transfer of aluminum and aluminum-alloy thin films in microfabrication, MEMS, and research metallization processes.

General behaviors (literature; not item-specific):

• Acidic aluminum etchants (e.g., H3PO4/HNO3/CH3COOH/H2O) act via oxidation of Al to soluble Al3+ species and complexation; nitric acid functions as an oxidizer while phosphoric acid promotes oxide dissolution and surface smoothing. Etching is typically isotropic, leading to lateral undercut beneath masks.
• Alkaline etchants dissolve Al via aluminate formation (e.g., [Al(OH)4]−), simultaneously evolving H2; rates increase with temperature and hydroxide concentration.

Process considerations:

• Etch rate control: Strongly temperature dependent (Arrhenius behavior). Agitation and fresh chemistry replenish oxidizer/complexant at the surface and remove reaction products; bath aging changes rate and selectivity.
• Alloy effects: Si, Cu, and Ti in Al alloys alter oxide chemistry and can slow etch or produce residues; periodic oxidizer refresh and surfactants (if present) can help, but composition-specific tuning is required.
• Masking: Positive/negative PR, SiO2, and Si3N4 are common masks. Verify compatibility windows to limit resist swelling or footing.
• Defect control: Particle control, DI rinsing cascades, and timed quench protocols reduce staining and pitting. Post-etch neutralization/rinse is critical to remove residues and prevent galvanic corrosion.

Use cases:

• Patterning interconnect lines, opening bond pads, removing blanket Al films, releasing MEMS structures where selective Al removal is required.

Always run coupon trials to calibrate time–temperature–agitation for your specific film stack and device topology.

Reaction Conditions

Item-specific operating parameters are not provided in the Product Data. The following are general, literature-based guidelines for wet etching of aluminum; they are NOT specifications for this item.

Typical parameters (acidic etchants, literature examples):

• Temperature: 20–50 C; higher temperature increases etch rate but may reduce mask selectivity and increase undercut.
• Agitation: Magnetic or recirculating flow to improve uniformity and suppress localized depletion.
• Etch rates: Tens to hundreds of nm/min for sputtered Al; alloying (Al–Si–Cu) can slow rates; oxide condition matters.
• Mask compatibility: Many PRs and SiO2 masks are viable; prolonged exposure or elevated temperature can attack PR. Conduct pretests.
• Endpointing: Time-based for blanket films; optical monitoring or profilometry for patterned features. Avoid over-etch into underlying layers (e.g., Ti, TiN); selectivity varies.

Typical parameters (alkaline etchants, literature):

• Temperature: 20–60 C; control for safe management of hydrogen evolution.
• Ventilation: Essential to disperse H2; avoid ignition sources.
• Etch behavior: Often faster vertical attack but poorer PR selectivity, increased roughness.

Rinsing and post-treatments:

• Immediate DI water quench, followed by multi-stage rinses to remove residues and prevent staining.
• Optional neutralization dips are process- and chemistry-specific; only perform if recommended by your SDS/CoA and fab protocols.

Always perform coupon calibration under your toolset and use the CoA/SDS for this lot to set safe and effective conditions.

Safety and Handling

Hazard classification for this specific product is not provided in the Product Data.

• Signal word, GHS classes, pictograms, H-statements: Not specified for this item; refer to the SDS.

General safety guidance for aluminum etchants (literature; not item-specific):

• Many aluminum etchants are strongly corrosive (acidic or caustic). Acidic formulations containing nitric acid can be oxidizing and may release NOx fumes; alkaline formulations can generate hydrogen gas when reacting with Al.
• PPE: Wear chemical-resistant gloves (e.g., butyl rubber or appropriate acid/caustic-rated gloves), splash goggles/face shield, lab coat/apron. Use in a fume hood to control vapors/aerosols and potential NOx.
• Storage incompatibilities: Keep away from bases (for acidic etchants), acids/oxidizers (for alkaline etchants), reactive metals, cyanides, and organic solvents incompatible with strong acids/bases. Avoid contact with strong reducers if nitric acid is present. Store in compatible materials (e.g., certain fluoropolymers, glass for acids; avoid aluminum fittings). Verify compatibility per SDS.
• First aid (overview; defer to SDS): Flush skin/eyes with copious water for ≥15 minutes; remove contaminated clothing. If inhaled, move to fresh air. If ingested, do not induce vomiting; seek medical attention immediately.
• Special risks and handling:
  • Never heat sealed containers; exotherms possible on dilution of strong acids/alkalis. Always add acid/base to water slowly with cooling and stirring if dilution is required (only if instructed by SDS/CoA).
  • Hydrogen evolution is possible during aluminum dissolution in alkaline solutions—ensure ignition source control and ventilation.

Always treat as corrosive and consult the product-specific SDS for authoritative guidance.

Solvent Selection

This product is a formulated etchant and is not intended to be used as an extraction or reaction solvent. Therefore, classic solvent selection criteria (polarity, Hansen parameters) are not directly applicable.

Practical compatibility notes (general, literature-based; not item-specific):

• Matrix: Typically aqueous; fully miscible with water when dilution is allowed by the SDS/CoA. Do not assume dilutability; confirm first.
• Material compatibility: Use fluoropolymer (PTFE, PFA) or other compatible plastics for tubing and labware. Avoid aluminum and many other reactive metals. Stainless steel compatibility depends on formulation and exposure time; verify.
• Photoresist/mask selectivity: Acidic aluminum etchants are generally more compatible with PR and SiO2 masks than strong bases, but selectivity is formulation- and temperature-dependent. Validate with test coupons.

When to choose vs. alternatives:

• Aluminum Etchant (acidic) is typically chosen for isotropic wet etch of Al films where smooth sidewalls and PR compatibility are desired.
• Alkaline etchants (e.g., NaOH) may be preferred for bulk removal, roughening, or when oxidizers must be avoided; they generally have poorer PR selectivity and generate hydrogen.

If you require a solvent for post-etch stripping or rinsing, select ultrapure DI water for immediate quench/rinse, followed by isopropanol or compatible drying agents as per your fab protocol. Always consult compatibility charts and your SDS before introducing any auxiliary solvents.

Storage and Reconstitution

• Storage conditions (from Product Data): Room temperature, Cool. Maintain in a cool, well-ventilated area away from incompatible materials. Do not expose to direct heat or sunlight. Keep container tightly closed to minimize contamination and evaporative drift.
• Shipped in: Normal (ambient) per Product Data.
• Reconstitution/dilution: Not specified for this item; refer to CoA/Spec Sheet and SDS. Do not assume dilutability. If dilution is permitted, follow standard acid/base handling: add etchant to water slowly with external cooling and stirring; never the reverse. Use only DI water of appropriate purity for electronic processes.
• Container/materials: Use compatible materials (e.g., PTFE/PFA) and secondary containment. Avoid aluminum and other reactive metals. Confirm compatibility with your specific chemistry via SDS.
• Stability/shelf life: Not specified for this item; refer to CoA/Spec Sheet. Monitor for changes in appearance or performance and follow your facility’s bath life and replacement criteria.
• Freeze–thaw: Not specified for this item; avoid freezing unless explicitly allowed by the CoA/SDS, as phase separation or crystallization can alter composition.

Always consult the lot-specific CoA and SDS for definitive storage, handling, and any permitted preparation steps. For research use only.

Structure and Identity

This product is an aluminum etching reagent intended for microfabrication and materials processing. It is a formulated mixture rather than a single, well-defined compound.

• SKU: A1511715
• Product Name: Aluminum Etchant (Electronic grade)
• Chemical identity: Formulated mixture; exact composition not specified for this item; refer to CoA/Spec Sheet and SDS.
• CAS: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Formula: Not applicable (mixture).
• Molecular Weight: Not applicable (mixture).
• SMILES/InChI/InChIKey: Not applicable (mixture).

Structural/functional features (general, literature):

• Aluminum etchants are commonly either:
  • Acidic mixtures (e.g., phosphoric acid/acetic acid/nitric acid/water) tuned for isotropic wet etching of Al thin films while maintaining acceptable photoresist/SiO2 selectivity.
  • Alkaline etchants (e.g., NaOH, KOH) that dissolve Al via aluminate formation with concomitant hydrogen evolution.
• No stereochemical features apply; function derives from solution acidity/basicity, oxidizing capacity, complexation, and transport properties.

Form factor and use:

• Supplied as a ready-to-use or concentrate liquid etchant (not specified for this item; refer to CoA/Spec Sheet). Designed for wet etch of Al and Al-alloys in microelectronics, MEMS, and general materials labs.

Important note:

• Because composition is not provided in the Product Data, do not extrapolate from generic formulations. Always consult the CoA/SDS shipped with your lot to confirm composition, compatibility, and process constraints.

Synthetic Utility

In the context of chemical processing, Aluminum Etchant functions as a selective dissolving medium for aluminum and aluminum alloys rather than as a reagent for bond-forming organic synthesis.

Utility in materials fabrication (literature; not item-specific):

• Pattern transfer: Enables removal of Al thin films beneath patterned masks to define interconnects, pads, and features in microelectronics and MEMS.
• Differential removal: Can offer selectivity against SiO2/Si3N4 and certain photoresists, enabling multi-layer stacks (e.g., Al over barrier/adhesion layers) to be processed with timed stops or combined endpointing.
• Surface preparation: Strips native Al2O3 and conditions surfaces prior to plating or deposition steps when used in brief dips (process-specific; verify impact on roughness and contamination).

Chemistry underpinnings:

• Acidic systems rely on oxidation of Al(0) to Al(III), oxide dissolution, and complexation to keep Al3+ in solution; isotropic transport leads to lateral undercut.
• Alkaline systems convert Al to soluble aluminate complexes with concurrent hydrogen evolution; surface roughness can increase due to localized gas formation.

Process integration tips:

• Sequence with DI quench, thorough rinsing, and controlled drying (e.g., IPA displacement or Marangoni) to minimize watermarks and corrosion.
• Validate compatibility with downstream lithography, dielectric deposition, and metallization to avoid residue-induced adhesion or electrical defects.

Target Specificity

Not applicable. This product is not a biological affinity reagent and has no antigen/epitope specificity. Its “target” in a materials sense is aluminum and certain aluminum alloys, where it dissolves the metal under controlled wet-etch conditions. See Reaction & Applications for details.