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CAS NO.：1624-01-7 Tetrakis(dimethylamino)silane |
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Product Name |
Tetrakis(dimethylamino)silane |
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Synonyms |
4DMAS; TDMAS (tetrakis); Tetrakis(dimethylamido)silane; Octamethylsilanetetramine; N,N,N′,N′,N″,N″,N‴,N‴-Octamethylsilanetetramine; (Me₂N)₄Si |
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CAS NO. |
1624-01-7 |
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Appearance |
Colorless to pale yellow liquid |
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Purity |
95% min |
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MF |
C₈H₂₄N₄Si |
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MW |
204.39 g/mol |
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Storage |
Preserve in a well-closed container and keep in cool, dry place, avoid light. |
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Package |
In fluoride bottle/ Fluoride drums/iron drums/plastic drums/IBC Tank ,etc. |
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Shipment method |
By Sea, Air, Courier door to door, etc. |
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Loading Port |
China any port, Beijing, Shanghai, Hong Kong etc. |
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Application |
1. Semiconductor ALD/CVD precursor (primary use): Halogen-free silicon precursor carrying four dimethylamido ligands, used for plasma-enhanced / thermal ALD and CVD of silicon dioxide (SiO₂, with ozone or O₂ plasma) and silicon nitride (SiNx, with NH₃/N₂ plasma) — spacer oxide, liner, gap-fill, hardmask and passivation layers in 3D NAND, DRAM and logic devices. The four reactive amido groups give high surface reactivity and high growth per cycle, with no chlorine / ammonium chloride by-product. |
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Contact |
Contact person: James Zhang Email: james.zhang@dakenchem.com |
Frequently Asked Questions：
Q:What is Tetrakis(dimethylamino)silane (4DMAS)?
A:Tetrakis(dimethylamino)silane, commonly abbreviated 4DMAS (and sometimes TDMAS in supplier catalogs), is an organoaminosilane with the linear formula [(CH₃)₂N]₄Si (CAS 1624-01-7, molecular formula C₈H₂₄N₄Si, MW 204.39). It is a colorless to pale-yellow liquid in which a central silicon atom carries four dimethylamino groups and no Si–H bond. It is a well-established halogen-free precursor for silicon oxide and nitride thin-film deposition.
Q:What is the difference between 4DMAS, 3DMAS and 3DMAMS?
A:They are different compounds — always order by CAS number. 4DMAS (CAS 1624-01-7) is Si(NMe₂)₄, with four dimethylamino groups. 3DMAS / tris(dimethylamino)silane (CAS 15112-89-7) is (Me₂N)₃SiH, with three dimethylamino groups plus a reactive Si–H bond. 3DMAMS / tris(dimethylamino)methylsilane (CAS 3768-57-8) is MeSi(NMe₂)₃, with a methyl group instead of Si–H. “TDMAS” is used ambiguously in the trade for both tris and tetrakis products, so the CAS number is the reliable identifier.
Q:What is 4DMAS used for in semiconductor manufacturing?
A:4DMAS is primarily used as a silicon source precursor for ALD/CVD of SiO₂ films (with ozone or oxygen plasma) and SiNx films (with ammonia or nitrogen plasma). Typical layers include gate/spacer oxide and nitride, liners in high-aspect-ratio 3D NAND structures, DRAM dielectrics, gap-fill and hardmask layers, and low-temperature passivation films where thermal budget is limited.
Q:Why choose 4DMAS over TEOS, dichlorosilane or silane?
A:As a halogen-free aminosilane, 4DMAS (a) contains no chlorine, avoiding NH₄Cl particle formation and chamber corrosion; (b) reacts efficiently with ozone at low temperature for true ALD-type oxide growth with precise, self-limiting thickness control; (c) carries four reactive amido ligands per molecule, giving high reactivity and high growth per cycle; and (d) is easier and safer to handle than pyrophoric silane, with liquid delivery from a heated bubbler.
Q:What purity do you supply?
A:Our standard grade is 95% min (by GC), suitable for R&D, pilot evaluation and industrial synthesis. Every batch is shipped with a Certificate of Analysis (COA). If your process requires tighter specifications — higher assay, controlled moisture or trace-metal limits for electronic-grade use — tell us your target spec and we will quote a custom-produced batch accordingly.
Q:What are the key physical properties for process design?
A:Melting point about 15–16 °C (the product may partially solidify in cool storage — gently warm and re-homogenize before use); boiling point about 196 °C (74–75 °C at 19 Torr); density 0.884 g/mL at 25 °C; refractive index about 1.443; flash point about 58 °C. Because of its low vapor pressure at room temperature, heated bubbler / vapor-draw delivery (typically 50–80 °C) is used in ALD/CVD tools.
Q:How should 4DMAS be stored and handled?
A:4DMAS is highly moisture-sensitive: it hydrolyzes rapidly on contact with water, liberating flammable and corrosive dimethylamine. Store in tightly sealed containers under dry nitrogen or argon, in a cool, dry, dark place, away from water, acids and oxidizers. Transfer via glovebox or Schlenk/cannula technique; use inert-gas-purged cylinders and bubblers. Full handling guidance is provided in the SDS.
Q:What packaging options are available?
A:Standard packaging is fluoride bottles, fluorinated / iron / plastic drums or IBC tanks according to order quantity. Because 4DMAS is moisture-sensitive, material is sealed dry under inert conditions before dispatch. Small sealed sample bottles are available for evaluation, and special packaging (stainless cylinders, ampoules, custom fittings) can be arranged on request for production use.
Q:Are COA, SDS and regulatory documents provided? How is it shipped?
A:Yes — each batch ships with COA and SDS; TDS, REACH/TSCA information and origin documents are available on request. 4DMAS is classified as a flammable, corrosive, water-reactive dangerous good (UN 2920 type entries) and is shipped through certified DG channels by air, sea or courier with complete dangerous-goods documentation for smooth customs clearance.
Q:Can I get a sample, custom specification or small-batch supply?
A:Absolutely. We support gram-scale samples for process evaluation, custom purity/metal-specification batches, and scale-up to production volumes, with stable lead times for repeat orders. Tell us your target application (SiO₂ ALD with ozone, SiNx PEALD…), required grade and cylinder type, and we will reply with specification, price, lead time and sample availability — usually within one working day. Contact James Zhang at james.zhang@dakenchem.com.
Application Cases：
Case 1 Logic Devices: Low-Temperature PEALD SiO₂ Spacer & Gap-Fill
4DMAS paired with ozone deposits dense, conformal SiO₂ at low chuck temperature in FinFET/advanced-node spacer and gap-fill modules. The chlorine-free chemistry eliminates NH₄Cl defects, and the four-amido reactivity delivers high growth per cycle with Ångström-level thickness control on fine-pitch structures.
Case 2 3D NAND Flash: Conformal SiO₂ Liner in High-Aspect-Ratio Holes
In deep channel holes and slit trenches of 3D NAND stacks, 4DMAS-based ALD oxide provides uniform step coverage and controlled liner thickness, avoiding the loading effects and particle issues associated with chloride-based precursors.
Case 3 SiNx Deposition as a Halogen-Free Alternative to DCS
Used with NH₃/N₂ plasma, 4DMAS deposits silicon nitride without dichlorosilane — no ammonium chloride powder in the pump line, no metal corrosion, and a wider low-temperature process window for spacer/liner nitride.
Case 4 — DRAM & Sensitive Stacks: Low-Thermal-Budget Dielectric Films
For DRAM capacitor dielectrics and other heat-limited stacks, 4DMAS enables quality SiO₂ deposition at temperatures compatible with fragile structures and earlier-built layers, supporting thermal-budget scaling.
Case 5 — Surface Silylation & Hydrophobic Treatment
Beyond deposition, 4DMAS is used as a strong silylating agent to hydrophobize silica, glass and fumed-silica surfaces, converting surface silanols and protecting moisture-sensitive materials in R&D and industrial surface treatment.
