Tetraethoxysilane, abbreviated as TEOS. Ethyl silicate is a colorless and transparent liquid at room temperature, with a special odor. Stable in the presence of no water, it decomposes into ethanol and silicic acid when in contact with water, becomes turbid in humid air, and is soluble in organic solvents such as alcohols and ethers. The molecular formula is (C2H5O) 4Si, with a melting point of -77 ℃ and a boiling point of 168.1 ℃. Toxic, strongly irritating to the eyes and respiratory tract. It is prepared by distillation after the reaction of silicon tetrachloride and anhydrous ethanol. Used for the production of heat-resistant and chemically resistant coatings and organic silicon solvents, as well as for organic synthesis, basic raw materials for the preparation of advanced crystals, optical glass processing agents, binders, insulation materials in the electronic industry, etc.
Physical property data
1. Description: Colorless flammable liquid with a pungent odor.
2. Melting point (℃): -77
3. Boiling point (℃): 168.1
4. Relative density (g/cm3): 0.9356
5. Flash point (℃): 51.67
6. Solubility: insoluble in water, soluble in ethanol, slightly soluble in benzene.
Molecular structure data
1. Molar refractive index: 54.80
2. Molar volume (cm3/mol): 221.7
3. Isometric volume (90.2K): 488.2
4. Surface tension (dyne/cm): 23.4
5. Polarization rate (10-24cm3): 21.72
Electronic grade TEOS is mainly used in the chemical vapor deposition (CVD) process of IC wafer manufacturing, generating silicon dioxide isolation layers and metal interlayer dielectric films. It is a relatively large amount of electronic chemicals required for the manufacturing of semiconductor integrated circuits, discrete devices, and microelectromechanical systems (MEMS)
Product features
Electronic grade TEOS has extremely high quality requirements, with a purity of over 8N and impurities of less than 1 ppb, especially metal ion impurities (Na, K, Mg, Fe, Ca, Al, etc.). Metal ions are electroactive impurities that can reduce the insulation performance of silicon dioxide thin film deposited on semiconductor devices, leading to interconnection of micron level circuits and circuit board scrap. The non electroactive impurities, such as moisture and organic matter, can affect the uniformity and smoothness of the deposited film layer.
Product indicators: purity ≥ 99.999%, total impurities ≤ 1ppb, Al ≤ 0.3ppb, cobalt ≤ 0.3ppb, iron ≤ 0.5ppb, manganese ≤ 0.3ppb, nickel ≤ 0.3ppb; Chlorine content ≤ 0.1 μ G/g, water<5 μ G/g, particle size (≥ 0.2 μ m) ≤ 10 pcs/ml.
synthetic method
Ethyl silicate is synthesized by reacting silicon tetrachloride with ethanol, which can be continuous or intermittent. The chemical reaction formula is as follows:
SiCl4+4C2H5OH → (C2H5O) 4Si+4HCl
Toxicity category
1. Category: Flammable liquid.
2. Toxicity classification: Poisoning
3. Acute toxicity: Oral LD50 in rats: 6270 mg/kg.
4. Stimulation data: Skin rabbit 500mg/24 hours moderate; Eye – Rabbit 500mg/24 hours mild.
5. Hazardous characteristics of explosives: can explode when mixed with air.
6. Flammability hazard characteristics: flammable; The fire emitted toxic silicon oxide smoke.
7. Storage and transportation characteristics: Ventilation and low-temperature drying in the warehouse; Separate storage and transportation from oxidants.
8. Extinguishing agent: foam, dry powder, carbon dioxide, sand.
