4109-96-0 Usage
Description
Dichlorosilane, also known as SiH2Cl2, is a colorless, toxic, flammable, and corrosive gas at room temperature and atmospheric pressure. It has a strong, repulsive odor and is easily ignited in air. Dichlorosilane is highly reactive with water, hydrolyzing rapidly to yield silica, silicon oxyhydride, and hydrochloric acid. It is shipped as a liquefied gas in low-pressure cylinders at its vapor pressure of 9.1 psig (62.7 kPa) at 70°F (21.1°C). Due to its reactivity, it should always be handled in dry equipment with a dry inert gas such as nitrogen.
Uses
Used in Electronics Industry:
Dichlorosilane is used as a silicon precursor for the growth of epitaxial or polycrystalline silicon and chemical vapor deposition of silicon dioxide and silicon nitride. It is an outstanding material for epitaxial deposition, depositing silicon more efficiently and at lower temperatures than other chlorosilanes. The deposition rate of dichlorosilane is not as temperature-sensitive as that of other chlorosilanes, allowing for better control by adjusting the dichlorosilane concentration in the hydrogen feedstream.
Used in Chemical Synthesis:
Dichlorosilane is used as an easier-to-handle form of dichlorosilane, giving improved yields in the reduction of imines over that of trichlorosilane.
Storage and Handling:
Dichlorosilane can be safely stored in mild steel equipment in the complete absence of water. However, in the presence of even small traces of water, it becomes extremely corrosive. Some examples of other common compatible materials used include Viton, Teflon, Kel-F, nickel, Monel, and some types of stainless steel. For transfer service, dry inert gas is preferred to pumping.
Grades available
Dichlorosilane is primarily sold in ultra-high-purity grades for use in the electronics industry. A typical specification usually quantifies the acceptable levels of hydrocarbons and metals.
Gas purity guidelines have been developed and published by Semiconductor Equipment and Materials International and can be found in the book of Book of SEMI Standards.
Preparation
Dichlorosilane is most commonly produced by the disproportionation of trichlorosilane in a catalytic redistribution reactor. The trichlorosilane is initially produced from metallurgical silicon that is reacted with hydrogen and silicon tetrachloride.
Physiological Effects
Dichlorosilane hydrolyzes and oxidizes readily to release hydrogen chloride; therefore, the symptoms, effects, and treatment will be similar to those for hydrogen chloride. Dichlorosilane will cause severe bums on contact with eyes, skin, and mucous membranes.
If dichlorosilane is inhaled, immediately remove the victim to fresh air. If breathing is dif- ficult, give oxygen. Prompt treatment by a physician is required even if no symptoms of exposure are evident since the symptoms may be delayed.
Inhalation of low concentrations of vapors will cause irritation of the respiratory tract, producing cough, excess sputum, and chest discomfort. Inhalation of vapors can cause severe irritation or bums of moist skin, mucous membranes, and the upper respiratory tract, as well as delayed pulmonary edema. Chronic exposure to the vapors may cause discoloration or erosion of the teeth, bleeding of nose and gums, and ulceration of the nasal mucosa.
Vapor contact with the eye will cause severe irritation experienced as pain in the eye, excess lachrymation, closure of the eyelids, and marked excess redness and swelling of the conjunctive. If high concentrations of hydrogen chloride vapor are formed, then corneal injury can occur. Splash contamination may cause severe conjunctivitis seen as marked excess redness and swelling of the conjunctive, discharge, iritis, and severe corneal injury. The corneal injury, if untreated, could result in permanent blindness.
Disposal
Dichlorosilane should not be discharged directly into surface waters or sewer systems since an acidic waste product is formed. The disposal can be accomplished by controlled introduction of the product into water. The exothermic reactions of dichlorosilane with water (hydrolysis) result in the formation of hydrochloric acid and an insoluble silicon containing solid or fluid. In order to prevent air pollution, the quantity of water must be sufticient to dissolve all of the hydrogen chloride that will be formed. The ratio of water to dichlorosilane should be at least 10 to 1. The corrosive and exothermic nature of the reaction should be considered in selecting materials of construction for the equipment used in this procedure.
The hydrochloric acid formed should then be neutralized with an alkali agent such as aqueous ammonia, sodium hydroxide, lime slurry, etc., and should be added as an aqueous solution with agitation to the acidic medium. Consideration must be given to the additional heat that will be produced by the neutralization.
Silicon-containing solids should be washed to remove residual acid. Discard any product, residue, disposable container, or liner in an environmentally acceptable manner. Disposal of dichlorosilane by neutralizing, scrubbing, incineration, or by other means, may be subject to permitting by federal, state or provincial regulations. Persons involved with disposal of dichiorosilane should check with the environmental authorities having jurisdiction to determine the applicability of permitting regulations to disposal activities.
Air & Water Reactions
Highly flammable. Based on the properties of similar materials, there is the possibility that the reaction of Dichlorosilane with water may be vigorous or violent. Products of the reaction include hydrogen chloride. The reaction generates heat and this heat may be sufficient to ignite the product. The chlorosilicon hydrides(ClxSiHy) are spontaneously flammable in air, NFPA 1991.
Reactivity Profile
Chlorosilanes, such as Dichlorosilane, are compounds in which silicon is bonded to from one to four chlorine atoms with other bonds to hydrogen and/or alkyl groups. Chlorosilanes react with water, moist air, or steam to produce heat and toxic, corrosive fumes of hydrogen chloride. They may also produce flammable gaseous H2. They can serve as chlorination agents. Chlorosilanes react vigorously with both organic and inorganic acids and with bases to generate toxic or flammable gases.
Hazard
Dichlorosilane is toxic by inhalation and skin absorption. Hydrogen chloride causes severe eye and skin burns and is irritating to the skin, eyes, and respiratory system. The four-digit UN identification number is 2189. The NFPA 704 designation is health 4, flammability 4, and reactivity 2. The white area at the bottom of the diamond contains a W with a slash through it, indicating water reactivity.
Health Hazard
TOXIC; may be fatal if inhaled or absorbed through skin. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution.
Fire Hazard
Flammable; may be ignited by heat, sparks or flames. May form explosive mixtures with air. Vapors from liquefied gas are initially heavier than air and spread along ground. Vapors may travel to source of ignition and flash back. Some of these materials may react violently with water. Cylinders exposed to fire may vent and release toxic and flammable gas through pressure relief devices. Containers may explode when heated. Ruptured cylinders may rocket. Runoff may create fire or explosion hazard.
Flammability and Explosibility
Extremelyflammableliquifiedgas
Safety Profile
Moderately toxic by
inhalation. Ignites spontaneously in air.
Confined mixtures with air are
spontaneously explosive. When heated to
decomposition it emits toxic fumes of Cl-.
See also CHLOROSILANES.
Physiological effects
Dichlorosilane hydrolyzes and oxidizes readily
to release hydrogen chloride; therefore, the
symptoms, effects, and treatment will be similar
to those for hydrogen chloride. Dichlorosilane
will cause severe bums on contact with eyes,
skin, and mucous membranes.
If dichlorosilane is inhaled, immediately remove
the victim to fresh air. If breathing is difficult,
give oxygen. Prompt treatment by a physician
is required even if no symptoms of exposure
are evident since the symptoms may be
delayed.
storage
Since dichlorosilane is a highly flammable, corrosive,
and toxic liquefied gas, appropriate precautions
must be taken in its storage and handling.
During the handling of chlorosilanes, the
use of such protective equipment as goggles,
neoprene or natural rubber gloves, and protective
clothing is essential. SCBAs, as well as
both safety showers and eyewash fountains,
should be available for emergency use.
Cylinders should be assigned a definite area
for storage. The area should be dry, cool, well
ventilated, fire resistant, and away from ignition
sources. Keep cylinders protected from excessive
temperature rise by storing them away from
radiators or other heat sources. Storage conditions
should comply with local and state regulations.
Cylinders may be stored in the open, but must
be protected against extremes of weather and
from the dampness of the ground to prevent
rusting. During the summer, cylinders stored in
the open should be shaded against the continuous
direct rays of the sun in those localities
where extreme temperatures prevail.
Waste Disposal
Dichlorosilane should not be discharged directly
into surface waters or sewer systems since an
acidic waste product is formed. The disposal
can be accomplished by controlled introduction
of the product into water. The exothermic reactions
of dichlorosilane with water (hydrolysis)
result in the formation of hydrochloric acid and
an insoluble silicon containing solid or fluid. In
order to prevent air pollution, the quantity of
water must be sufticient to dissolve all of the
hydrogen chloride that will be formed. The ratio
of water to dichlorosilane should be at least 10
to 1. The corrosive and exothermic nature of the
reaction should be t;onsidered in selecting materials
of construction for the equipment used in
this procedure.
The hydrochloric acid formed should then be
neutralized with an alkali agent such as aqueous
ammonia, sodium hydroxide, lime slurry, etc.,
and should be added as an aqueous solution
with agitation to the acidic medium. Consideration must be given to the additional heat that
will be produced by the neutralization.
Silicon-containing solids should be washed to
remove residual acid. Discard any product, residue,
disposable container, or liner in an environmentally
acceptable manner. Disposal of
dichlorosilane by neutralizing, scrubbing, incineration,
or by other means, may be subject to
permitting by federal, state or provincial regulations.
Persons involved with disposal of dichiorosilane
should check with the environmental
authorities having jurisdiction to determine
the applicability of permitting regulations
to disposal activities.
GRADES AVAILABLE
Dichlorosilane is primarily sold in ultra-
high-purity grades for use in the electronics
industry. A typical specification usually quantifies
the acceptable levels of hydrocarbons and
metals.
Gas purity guidelines have been developed
and published by Semiconductor Equipment
and Materials International and can be found in
the book of Book ofSEMI Standards [1].
Check Digit Verification of cas no
The CAS Registry Mumber 4109-96-0 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 4,1,0 and 9 respectively; the second part has 2 digits, 9 and 6 respectively.
Calculate Digit Verification of CAS Registry Number 4109-96:
(6*4)+(5*1)+(4*0)+(3*9)+(2*9)+(1*6)=80
80 % 10 = 0
So 4109-96-0 is a valid CAS Registry Number.
InChI:InChI=1/Cl2Si/c1-3-2
4109-96-0Relevant articles and documents
SYNTHESIS OF ORGANO CHLOROSILANES FROM ORGANOSILANES
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Page/Page column 36; 37, (2019/04/16)
The invention relates to a process for the production of chlorosilanes by subjecting one or more hydndosilanes to the reaction with hydrogen chloride in the presence of at least one ether compound, and a process for the production of such hydndosilanes serving as starting materials.
Amorphous silicon: New insights into an old material
Spomer, Natalie,Holl, Sven,Zherlitsyna, Larissa,Maysamy, Fariba,Frost, Andreas,Auner, Norbert
, p. 5600 - 5616 (2015/03/30)
Amorphous silicon is synthesized by treating the tetrahalosilanes SiX4 (X=Cl, F) with molten sodium in high boiling polar and non-polar solvents such as diglyme or nonane to give a brown or a black solid showing different reactivities towards suitable reagents. With regards to their technical relevance, their stability towards oxygen, air, moisture, chlorine-containing reaction partners RCl (R=H, Cl, Me) and alcohols is investigated. In particular, reactions with methanol are a versatile tool to deliver important products. Besides tetramethoxysilane formation, methanolysis of silicon releases hydrogen gas under ambient conditions and is thus suitable for a decentralized hydrogen production; competitive insertion into the MeO-H versus the Me-OH bond either yields H- and/or methyl-substituted methoxy functional silanes. Moreover, compounds, such as MenSi(OMe)4-n (n=0-3) are simply accessible in more than 75% yield from thermolysis of, for example, tetramethoxysilane over molten sodium. Based on our systematic investigations we identified reaction conditions to produce the methoxysilanes MenSi(OMe)4-n in excellent (n=0:100%) to acceptable yields (n=1:51%; n=2:27%); the yield of HSi(OMe)3 is about 85%. Thus, the methoxysilanes formed might possibly open the door for future routes to silicon-based products. Amorphous silicon is easily synthesized from tetrahalosilanes SiX4 (X=Cl, F) and molten sodium in different solvents. Reactivity studies prove the resulting materials as versatile tools for the formation of technical important silanes, such as the silicon chloro-, alkoxy-, and methylalkoxy-substituted derivatives (see figure; bl=black, br=brown).
METHOD OF MAKING A TRIHALOSILANE
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Page/Page column 24, (2012/06/30)
A method of making a trihalosilane comprising contacting an organotrihalosilane according to the formula RS1X3 (I), wherein R is C1-C10 hydrocarbyl and each X independently is halo, with hydrogen, wherein the mole ratio of the organotrihalosilane to hydrogen is from 0.009:1 to 1:2300, in the presence of a catalyst comprising a metal selected from (i) Re, (ii) a mixture comprising Re and at least one element selected from Pd, Ru, Mn, Cu, and Rh, (iii) a mixture comprising Ir and at least one element selected from Pd and Rh, (iv) Mn, (v) a mixture comprising Mn and Rh, (vi) Ag, (vii) Mg, and (viii) Rh at from 300 to 800 °C to form a trihalosilane.