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Hexamethyldisilazane

CAS Number
999-97-3
EC Number
213-668-5
Chemical Formula
C6H19NSi2
Molecular Weight
161.39 g/mol

Description

Hexamethyldisilazane (CAS 999-97-3 ), commonly abbreviated as HMDS, is a silylating agent used across semiconductor fabrication, surface chemistry, and specialty coatings. Bis(trimethylsilyl)amine is a recognized alternative name in chemical procurement. It functions by converting surface hydroxyl groups into trimethylsilyl groups, rendering substrates hydrophobic. This process improves adhesion or compatibility with downstream processes. In semiconductor manufacturing, HMDS is applied as a photoresist adhesion promoter for silicon wafer surfaces. Treating surfaces before lithography helps to prevent delamination and improve pattern resolution. Pharmaceutical and analytical laboratories use it to silylate active compounds. It is also used for chromatography column packings, improving compound stability and peak symmetry in GC analysis. In specialty coatings, it modifies the surface of silica and titanium dioxide. This improves dispersion in hydrophobic resin systems. Personal care formulators apply HMDS-treated powders in cosmetic products where improved skin feel and moisture resistance are required. HMDS is supplied as a colorless liquid in standard packaging ranging from small reagent quantities up to bulk drums. Technical and reagent grades are the most commonly available. Purity specifications are typically at 97% or higher depending on application requirements. Semiconductor-grade material is available under tighter purity controls for microelectronics. Contact us for supply of Hexamethyldisilazane Request Quote

Other Names (Synonyms)

Trimethyl-N-(trimethylsilyl)silanamine | Bis(trimethylsilyl)amine | 1,1,1,3,3,3-Hexamethyldisilazane | (TMS)2NH | ((CH3)3Si)2NH | HMDS | 1,1,1-Trimethyl-N-(trimethylsilyl)silanamine | Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-

Key Technical Features

  • High Purity Grade standard
  • Consistent Batch Quality
  • Full Regulatory & REACH Support
  • Global Logistics Network enabled

Physical Properties

Melting Point-78 °C
Boiling Point125 °C
Density0.7741 g/cm³ @ Temp: 25 °C
Flash Point57.2 °F
AppearanceColorless liquid
ColorColorless
OdorAmmonia odour
FormLiquid
Water SolubilityREACTS
Vapor Pressure20 hPa (20 °C)
Refractive Indexn 20/D 1.407(lit.)
Log P0.23-1.19 at 20-25℃

Safety & Handling

Danger
GHS02· FlammableGHS05· CorrosiveGHS06· ToxicGHS07· IrritantGHS08· Health Hazard

Hazard Statements

H225Highly Flammable liquid and vapor
H302Harmful if swallowed
H311Toxic in contact with skin
H314Causes severe skin burns and eye damage
H320Causes eye irritation
H331Toxic if inhaled
H332Harmful if inhaled
H335May cause respiratory irritation
H336May cause drowsiness or dizziness
H370Causes damage to organs
H402Harmful to aquatic life
H412Harmful to aquatic life with long lasting effects H302+
H332Harmful if swallowed or if inhaled

Precautionary Statements

P210Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
P233Keep container tightly closed.
P240Ground and bond container and receiving equipment.
P241Use explosion-proof equipment.
P242Use non-sparking tools.
P243Take action to prevent static discharges.
P260Do not breathe dust/fume/gas/mist/vapours/spray.
P261Avoid breathing dust/fume/gas/mist/vapours/spray.
P262Do not get in eyes, on skin, or on clothing.
P264Wash … thoroughly after handling.
P270Do not eat, drink or smoke when using this product.
P271Use only outdoors or in a well-ventilated area.
P273Avoid release to the environment.
P280Wear protective gloves/protective clothing/eye protection/face protection.
P316Get emergency medical help immediately.
P317Get emergency medical help.
P319Get medical advice/attention if you feel unwell.
P321Specific treatment (see … on this label).
P330Rinse mouth.
P363Wash contaminated clothing before reuse.
P405Store locked up.
P501Dispose of contents/container in accordance with local regulations.
P265Wash … thoroughly after handling.
P317Get emergency medical help.
P352IF ON SKIN: Wash with plenty of water.
P340IF INHALED: Remove person to fresh air and keep comfortable for breathing.
P316Get emergency medical help immediately.
P317If eye irritation persists: Get medical advice/attention. Get emergency medical help.
P364Take off immediately all contaminated clothing and wash it before reuse.
P378Use … for extinction.
P233Store in a well-ventilated place. Keep container tightly closed.
P235Store in a well-ventilated place. Keep cool.
P331Rinse mouth. Do NOT induce vomiting.
P354IF ON SKIN: Take off immediately all contaminated clothing. Rinse skin with water/shower.
P353IF ON SKIN (or hair): Take off immediately all contaminated clothing. Rinse skin with water/shower.
P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

Trade & Regulatory

HS Code29319099
UN Number3286
ADR Class3
Packing GroupII
Storage Class3 - Flammable liquids
WGK (Germany)2