| HS Code | 696904 |
| Product Name | Ammonia Water Electronic/EL Grade |
| Chemical Formula | NH4OH (NH3·H2O) |
| Cas Number | 1336-21-6 |
| Molecular Weight | 35.04 g/mol (as NH4OH) |
| Appearance | Clear, colorless liquid |
| Odor | Pungent, sharp ammonia odor |
| Concentration | 28-30% NH3 in water |
| Purity | Semiconductor/EL grade (trace-metal impurities controlled) |
| Density | 0.90 g/mL at 20°C |
| Boiling Point | 38°C at 760 mmHg |
| Ph | 12.0-12.4 at 20°C (concentrated solution) |
| Solubility | Fully miscible with water |
| Vapor Pressure | ~200 mmHg at 20°C |
As an accredited Ammonia Water Electronic/EL Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Packaged in 4L clean HDPE bottles with leak-proof seals. EL-grade ammonium hydroxide, high purity, for electronic semiconductor applications. |
| Container Loading (20′ FCL) | 20' FCL: Secure HDPE drums/pails of Electronic Grade Ammonia Water, upright, with proper segregation, ventilation, and spill containment. |
| Shipping | Ammonia Water Electronic/EL Grade ships in sealed, corrosion-resistant containers under hazmat regulations. Proper labeling, ventilation, and temperature control prevent vapor release and contamination. Transport via ground freight only, with trained handlers and compatible segregation from acids. Deliveries require secure upright storage and immediate inspection upon receipt. |
| Storage | Store Electronic/EL Grade Ammonia Water in tightly sealed, high-purity polyethylene or fluoropolymer containers to prevent contamination and ammonia loss. Keep in a cool, well-ventilated area away from heat, sunlight, acids, and incompatible materials. Maintain stable temperatures; avoid carbon dioxide exposure. Use dedicated, clean transfer equipment to preserve ultra-high purity. |
| Shelf Life | Shelf life: 12 months from manufacture date when stored tightly sealed in original container under cool, dry conditions. |
On 300 mm front-end logic and memory fabrication lines, electronic-grade (EL) ammonium hydroxide with 28.0–30.0 wt% NH₃ and metallic impurity levels controlled to SEMI C14 specifications functions as the surface-conditioning alkalinity source in ammonia–hydrogen peroxide wet processing. The standard cleaning bath is prepared at a volumetric ratio of 1 part 29% NH₄OH, 1 part 30% H₂O₂, 5 parts ultrapure water and is maintained at 65–80 °C in temperature-controlled quartz or perfluoroalkoxy-lined immersion tanks. Megasonic transducers operating in the 700–900 kHz band generate cavitation-controlled particle-removal forces across the wafer surface while the alkaline peroxide mixture oxidizes organic films, dissolves surface-conditioning residues, and lifts particulate contaminants by shifting the zeta potential between silicon dioxide and alumina fines. In production, the open-bath failure mode is concentration drift: ammonia volatilization and hydrogen peroxide decomposition can shift the pH by 0.2–0.4 units within 1–2 h, and uncontrolled drift produces particle redeposition and polysilicon micro-roughening. To suppress this, batch tanks use chilled reflux covers, inline near-infrared ammonia concentration measurement, density-compensated spiking of fresh 29% NH₄OH, and 0.1 μm point-of-use PTFE filtration. The cleanroom environment is held at ISO 14644-1:2015 Class 1–3, and chemical distribution piping is passivated high-purity perfluoroalkoxy resin to prevent metal leaching. Terminal output from this process includes front-end-of-line wafers for FinFET logic, dynamic random-access memory, and three-dimensional NAND flash products, where the cleaned surface proceeds to gate dielectric formation, shallow trench isolation, or pre-diffusion thermal treatment.
Table 1. Comparative process-parameter matrix for low-metal ammonium hydroxide cleaning baths
| Application track | NH₄OH 29%:H₂O₂ 30%:UPW volume ratio | Temperature | Time | Critical control target | Terminal product |
|---|---|---|---|---|---|
| Semiconductor front-end SC-1 cleaning | 1:1:5 | 65–80 °C | 600–900 s | pH drift ≤0.4 units per bath life | FEOL logic/memory wafers |
| Display array post-ash residue removal | 1:1:10 | 35–50 °C | 180–420 s | Mo etch rate ≤0.5 nm/min | TFT-LCD/OLED array plates |
| Photovoltaic post-texture clean | 1:1:20 | 60–65 °C | 300–600 s | Carbonate ≤5 ppm | PERC/TOPCon/HJT cells |
| LED/RF substrate pre-epitaxy clean | 1:1:20 | 40–50 °C | 300 s | Root-mean-square roughness increase ≤0.2 nm | GaN-on-SiC/GaN-on-sapphire epiwafers |
Silica-based interlayer dielectric slurries used in chemical mechanical planarization exhibit a sharp response to ammonium hydroxide addition because the dispersant demand and the surface charge on fumed-silica abrasives change within a narrow alkaline window. The material is charged into the slurry blend at 0.15–0.35 wt% of final slurry mass as 29% NH₄OH, but the operating target is a pH endpoint of 10.0–10.6 measured with a glass electrode per ASTM E70-22. In production, the blend is circulated through high-density polyethylene tote tanks fitted with 0.5 μm polypropylene depth filters and a single-particle optical sizer; the addition rate is trimmed by pH slope rather than by fixed weight because aging silica agglomerates consume alkalinity at a rate that varies batch to batch. Below pH 9.7, slurry particles form gel-like aggregates that raise large particle counts above 200 counts/mL on 0.5 μm channels, while above pH 10.8 the oxide removal rate on 300 mm tetraethylorthosilicate blanket wafers increases beyond 250 nm/min and degrades within-wafer non-uniformity beyond 5%. The polisher platform, typically a four-head rotary machine operating at platen speed 60–90 rpm and carrier back-pressure 1.5–4.0 psi, is sensitive to alkali over-dosing because excessive ammonium hydroxide raises copper dissolution in downstream damascene applications; in mixed copper-oxide processing, the pH setpoint is pulled back to 9.8–10.2. Compliance for the ammonia raw material is anchored to SEMI C14, and the slurry is monitored for soluble copper, aluminum, and sodium because even 1 ppb contamination shifts the dielectric constant after anneal. Published data for ammonium-hydroxide-based barrier CMP additives is limited, so qualification is performed by blanket removal-rate coupons and in-line defect maps rather than by extrapolated library values. Terminal products are planarized multilevel copper/low-k interconnect wafers for logic and memory devices.
Large-generation thin-film transistor array lines replace tetramethylammonium hydroxide with low-metal ammonium hydroxide in post-ash residue removal because amine-based strippers can attack aluminum-alloy line edges or alter the threshold voltage of oxide semiconductor channels. The process bath is blended at 1 part 29% NH₄OH, 1 part 30% H₂O₂, 10 parts ultrapure water, with temperature held at 35–50 °C in shower-type batch cleaning tools designed for Gen 8.5 and Gen 10.5 glass substrates. The alkalinity dissolves fluorocarbon and polyimide-like etch residues while leaving indium–gallium–zinc oxide active layers within acceptable sheet resistance drift; for molybdenum source-drain pads, pH is maintained near 10.3 because above 10.8 the molybdenum etch rate exceeds 0.5 nm/min, producing line-width loss above 0.1 μm. The cleaning chemistry is distributed through high-purity PVDF lines with 0.1 μm point-of-use filtration, and the controlled environment follows ISO 14644-1:2015 Class 3–5. Raw-material compliance is verified against SEMI C14 trace element limits, and final residue verification uses total-reflection X-ray fluorescence with acceptance values below 1×10¹⁰ atoms/cm² for heavy metals. Terminal output consists of array plates for thin-film transistor liquid crystal modules and active-matrix organic light-emitting diode panels. Published data for specific Gen 10.5 ammonia-peroxide process conditions is limited outside panel-maker qualification reports, so ramp-up requires defect inspection, contact-angle measurement, and electrical test sampling.
The critical metal contamination constraint in monocrystalline photovoltaic cell processing is addressed by integrating electronic-grade ammonium hydroxide into the batch wet-bench sequence after saw damage removal and alkaline texturing. For post-texture cleaning, a dilute SC-1 bath is prepared at 1 part 29% NH₄OH, 1 part 30% H₂O₂, 20 parts ultrapure water, heated to 60–65 °C, with immersion time between 300 s and 600 s. The alkaline peroxide mixture removes residual organic additives from potassium hydroxide–isopropyl alcohol texturing, dissolves fine silicon carbide particulate residue from diamond wire sawing, and complexes residual copper and iron that would otherwise accelerate light- and elevated-temperature-induced degradation. Production tanks are nitrogen-blanketed because atmospheric carbon dioxide can generate carbonate ions in the ammonia bath; carbonate film on textured pyramid tips reduces screen-printed front-side silver contact adhesion. The wet-bench environment is maintained at ISO 14644-1:2015 Class 5–6, rinsing uses ultrapure water with resistivity 18 MΩ·cm at 25 °C, and the ammonia source is controlled to SEMI C14 impurity specifications. Terminal cells include passivated emitter rear-contact, tunnel oxide passivated-contact, and silicon heterojunction architectures where the cleaned textured surface proceeds to diffusion, passivation, and front metallization.
Electronic-grade ammonium hydroxide is used as the nitrogen-containing feed in the controlled synthesis of electronic-grade ammonium fluoride and ammonium bifluoride for buffered oxide etch formulations. The reaction combines 29% NH₄OH with 49% HF at an NH₃:HF molar ratio of 1.00:1.00 for ammonium fluoride solution and 1.00:2.00 for ammonium bifluoride, with the exothermic neutralization temperature clamped below 30 °C in a fluoropolymer-lined continuous stirred-tank reactor. The ammonium hydroxide feed is trimmed to a pH endpoint of 6.6–7.2 for the monofluoride product; a lower endpoint of 3.3–3.9 shifts the product to bifluoride. Wetted components are PTFE and PFA, mixing uses a PTFE-coated impeller at 80–120 rpm, and the resulting solution passes through 0.1 μm PTFE cartridge filtration before filling into high-density polyethylene containers inside an ISO 14644-1:2015 Class 3 packaging environment. The ammonia feed must meet SEMI C14 trace-metal limits, while the resulting ammonium fluoride is typically supplied under SEMI C13 specifications. Terminal consumption includes 5:1, 10:1, and 30:1 buffered oxide etch baths that remove thermal and deposited silicon dioxide in semiconductor device fabrication while preserving silicon nitride and polysilicon layers.
Pre-epitaxy surface conditioning on polished sapphire and 4H-SiC substrates uses a low-concentration ammonia-peroxide mixture because elevated pH roughens vicinal step edges and alters the off-cut geometry required for subsequent gallium nitride growth. The bath is prepared at 1 part 29% NH₄OH, 1 part 30% H₂O₂, 20 parts ultrapure water, with temperature 40–50 °C and immersion time 300 s, corresponding to an ammonia equivalent concentration of 0.5–1.0 wt% NH₃. Under these conditions, organic residues and residual alumina/silica polishing fines are removed without increasing root-mean-square roughness by more than 0.2 nm on 2-inch sapphire witness samples; higher ammonia equivalents create microtexture that reduces carrier mobility in aluminum-gallium-nitride heterostructures. The cleaning line operates under ISO 14644-1:2015 Class 3–4, and the ammonia source is certified to SEMI C14 electronic-grade limits with point-of-use particle filtration at 0.1 μm. Metal contaminant density on the wafers is verified by total-reflection X-ray fluorescence with acceptance below 1×10¹⁰ atoms/cm². Terminal products are gallium nitride-on-silicon carbide high-electron-mobility transistor wafers for RF power amplification and gallium nitride-on-sapphire light-emitting diode epiwafers for solid-state lighting.
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Ammonia Water Electronic/EL Grade is a high-purity aqueous ammonium hydroxide solution supplied for front-end semiconductor wet processing, flat-panel display cleaning, and photomask surface preparation. The product is often designated by supplier-specific model codes such as EL-NH4OH-29 or equivalent electronic/EL identifiers, with the EL term referring to control of trace metal, anion, and particulate contamination. The aqueous phase is normally released at an ammonia assay of 28.0–30.0 wt%, corresponding to a concentrated ammonium hydroxide solution; point-of-fill filtration is typically conducted through 0.05 µm to 0.1 µm polytetrafluoroethylene or high-density polyethylene capsule filters. Because the product is intended for contact with silicon dioxide, polysilicon, and metal interconnect surfaces, the certificate of analysis includes per-element metal concentrations, anionic contaminants, total organic carbon, and cumulative particle counts in defined size bins.
The principal difference is not total ammonia content but the concentration and consistency of nonvolatile and ionic contaminants. Technical-grade ammonium hydroxide may be adequate for pH adjustment in waste neutralization, but it can contain sodium, potassium, calcium, iron, chloride, and sulfate at concentrations that are unacceptable for gate oxide integrity and shallow junction devices. In electronic/EL grade material, release criteria are typically aligned with SEMI C7 and are verified by inductively coupled plasma mass spectrometry per ASTM D5673, ion chromatography per ASTM D4327, and titrimetric or ion-selective electrode assay per ASTM D1426. Table 1 lists representative supplier acceptance limits for comparison; batch-specific values may be tighter for specialty line fills.
| Parameter | Technical-grade NH4OH | Electronic/EL Grade NH4OH | Analytical reference |
|---|---|---|---|
| Assay as NH3 | 20–30 wt%, variable by distillation cut | 28.0–30.0 wt% | ASTM D1426 |
| Sodium | ≤1,000 ppb | ≤10 ppb | ASTM D5673 |
| Potassium | ≤500 ppb | ≤10 ppb | ASTM D5673 |
| Iron | ≤500 ppb | ≤10 ppb | ASTM D5673 |
| Chloride | ≤2,000 ppb | ≤200 ppb | ASTM D4327 |
| Sulfate | ≤1,000 ppb | ≤200 ppb | ASTM D4327 |
| Particles ≥0.5 µm | not consistently controlled | ≤100 counts/mL | laser particle counting |
| Residue after evaporation | not consistently controlled | ≤5 ppm | supplier gravimetric method |
In product classification, electronic/EL grade is distinguished from technical-grade ammonium hydroxide and ACS reagent-grade material by the breadth of analytical release testing rather than by a simple purity label. Technical-grade ammonium hydroxide may meet a gross assay specification but still contains variable quantities of sodium, chloride, sulfate, and suspended solids from raw materials and storage tanks. ACS reagent-grade ammonium hydroxide is defined by residue after ignition, heavy metals, chloride, sulfate, and phosphate limits, but its specifications do not include laser particle counts or the full per-element trace-metal screen required for gate oxide integrity. The EL designation therefore imposes additional constraints on packaging cleanliness, filter retention, and trace organic content, and it is intended for processes where impurity-related leakage current or metallic contamination is a direct yield loss mechanism.
In RCA Standard Clean 1 chemistry, the product is mixed with hydrogen peroxide and deionized water at volume ratios commonly from 1:1:5 to 1:1:200 and heated to 60–80 °C. The alkaline peroxide mixture oxidizes and undercuts organic particles; trace-metal contamination in the ammonia water directly competes with this cleaning mechanism by depositing onto silicon or silicon dioxide surfaces. For critical gate oxide processing, per-element cation limits of ≤10 ppb are often required because sodium and potassium are mobile in oxides and can cause threshold voltage instability. Recirculating wet benches equipped with 0.05 µm point-of-use filters and high-purity perfluoroalkoxy polymer or quartz baths are specified to prevent recontamination. The bath temperature must be held within a narrow range: above 80 °C, hydrogen peroxide decomposition accelerates and ammonia loss can shift cleaning pH and reduce particle removal efficiency; below 60 °C, the organic removal rate decreases. Published data for specific bath-ageing behavior under photoresist loading are limited, but the temperature boundary is a standard wet-bench control point.
The product also functions as a pH adjuster in oxide and tungsten chemical mechanical planarization slurries and in post-CMP cleaning formulations. Addition is controlled by automated pH metering loops; metallic impurities in lower-grade ammonia water can alter slurry zeta potential and increase defectivity. In copper/low-κ integration, the alkaline component must be rinsed rapidly because residual ammonia water can attack exposed cobalt or copper interfaces. The operational boundary is therefore not defined solely by ammonia assay but by the point-of-use condition of the bath, the rinse sequence, and the metal stack.
The product is shipped in high-density polyethylene, fluoropolymer-lined, or internally coated containers. Storage below 25 °C in a chemical-compatible, pressure-relieved cabinet is required because ammonia partial pressure increases with temperature and closed unvented containers can build headspace pressure. Carbon dioxide ingress from cleanroom air reacts with ammonia to form ammonium carbonate species, raising particle counts and consuming free ammonia; therefore, day tanks and recirculating distribution lines are blanketed with filtered nitrogen and sealed against ambient air. The solution is incompatible with sodium hypochlorite, strong acids, aluminium alloys, copper, brass, and galvanized steel; suitable wetted materials include polyvinylidene fluoride, perfluoroalkoxy polymer, polytetrafluoroethylene, and polypropylene. For transport, the solution is classified under UN 2672 for ammonia solution with relative density between 0.880 and 0.957 at 15 °C. Direct skin or eye contact and inhalation of ammonia vapour are controlled by local exhaust ventilation and chemical protective equipment.
The EL-grade product is used in aqueous photoresist residue removal after plasma etching and ion implantation, often in mixtures with hydrogen peroxide, chelating agents, and wetting agents. Unlike organic strippers based on N-methyl-2-pyrrolidone or dimethyl sulfoxide, the ammonia-water system is water-soluble, reduces volatile organic solvent loading, and can be rinsed without intermediate solvent displacement. The replacement is not universal: copper and aluminium alloy interconnects are susceptible to alkaline corrosion at high pH, and inhibitor packages such as benzotriazole or silicate-based additives may be required. The cleaning rate depends on the cross-link density of the resist, the ion implantation dose, and the post-etch crust thickness; published data for specific film stacks are limited because residue composition is fab-specific.
On single-wafer spray processors, dispensing temperature and chemical flow rate are controlled at point-of-use; typical operating ranges are 25–65 °C, with dilution ratios determined by residue thickness. The product's low particle content is critical because residues redeposited on patterned wafers can create bridging defects in dual damascene structures. For aluminium BEOL applications, exposure time is constrained to avoid metal etch and pitting; in-line scanning electron microscopy is used to confirm residue clearance and absence of corrosion undercut.
The regulatory restriction of N-methyl-2-pyrrolidone under European Commission Regulation (EU) 2020/2096 reinforces the shift toward aqueous residue removal formulations, but ammonia water is not a drop-in replacement for solvent-based strippers in all integrated flows because solvent penetration into highly cross-linked negative resists may be faster than aqueous alkaline diffusion. In those cases, a solvent pre-wet or a sequence of solvent stripping followed by EL-grade aqueous cleaning is used.
Ammonia-water headspace behaviour is governed by the equilibrium between dissolved ammonia and gaseous ammonia. In 28.0–30.0 wt% solution, the vapour pressure of ammonia is high enough that day tanks and closed containers require pressure-rated design, nitrogen blanketing, and local exhaust. Temperature excursions above 25 °C accelerate ammonia loss and increase internal pressure; therefore, process lines are typically supplied through pressurised chemical distribution systems with perfluoroalkoxy polymer tubing and 0.05 µm point-of-use filtration. Carbon dioxide ingress is a parallel fault mode: absorbed CO₂ consumes free ammonia and forms carbonate species, shifting pH and creating a particle source. Mass flow controllers and conductivity or refractive index monitors are sometimes used to verify concentration at the point of dispense; however, published performance data for specific distribution designs are limited because the leak rate, dead-leg volume, and return-line design dominate batch-to-batch consistency.
Glass bottles are not recommended for long-term storage because alkaline attack can leach silicate and sodium; high-density polyethylene and fluoropolymer containers are the preferred primary packaging. In recirculating systems, pressure relief must be routed to ammonia-compatible scrubbers or local exhaust, and secondary containment should be proof-tested against the maximum working pressure of the day tank. These are operational boundaries rather than optional handling preferences.
For diffusion furnace quartzware cleaning, the EL-grade product is diluted with ultrapure water to 5–10 vol% and used to rinse quartz tubes, boats, and injectors. Sodium and potassium from technical-grade ammonia water can adsorb onto quartz and subsequently diffuse into the silicon during oxidation; therefore, the metal screen of the EL grade is a direct furnace cleanliness control. After cleaning, the parts are rinsed with ultrapure water and dried with filtered nitrogen. Residue removal is verified by surface photometry or by a thermal oxide contamination test on dummy wafers.
Analytical sample handling is itself a source of specification drift. Samples for trace-metal analysis are collected in acid-cleaned perfluoroalkoxy or high-density polyethylene bottles, and the sample must not pass through copper or brass fittings. For anion analysis by ion chromatography, sample preservation is not required because the high pH suppresses microbial growth; however, the sample must be sealed from carbon dioxide during transit. Laser particle counts are run within 24 h of sampling because ammonium carbonate particles can form in the headspace if ambient air is admitted. These controls are part of the release protocol and are referenced in supplier certificates of analysis.
Lot release testing for Ammonia Water Electronic/EL Grade is performed with inductively coupled plasma mass spectrometry, ion chromatography, total organic carbon analysis, and laser particle counting. The analytical sample is drawn from the filled container or distribution loop, and the certificate of analysis is reviewed against end-user process specifications. For critical 300 mm wafer production, additional point-of-use checks may include particle counts in the 0.2 µm and 0.5 µm channels, pH verification, and specific ion screening. The product is not interchangeable with ungraded ammonium hydroxide in front-end applications because ungraded material can introduce mobile-ion contamination and particle defects that are not corrected by downstream rinsing.
