1. The present invention relates to a method for the purification of halogenated oligosilanes as a pure compound or mixture of compounds each having at least one direct Si—Si bond, the substituents thereof being exclusively halogen or halogen and hydrogen, and the composition thereof being an atom ratio of substituent:silicon of at least 3:2, by the action of at least one purification agent on the halogenated oligosilane and isolation of the halogenated oligosilane with improved purity.

2.1. In the prior art, halogenated monosilanes such as HSiCl.sub.3 are purified by treatment with preferably polymeric organic compounds containing amino groups, and are separated out from these mixtures. This method cannot be used for halogenated oligosilanes because of the contained amino groups, since secondary reactions would lead to decomposition of the products. The new method should provide the desired products in high yield and purity without amino groups being used.

2.2. The purification of the halogenated oligosilanes is carried out in the presence of special purification agents, which convert contaminations such as, for example, FeCl.sub.2 into an insoluble and/or less volatile form. A separation of the products of completes the purification This method gives a high yield and avoids the problems associated with the prior art, such as, for example, long distillation times.

2.3. The method is suitable for the purification of, for example, Si.sub.2Cl.sub.6, Si.sub.3Cl.sub.8, Si.sub.4Cl.sub.10, and higher homologs. These find application, for example, in the deposition of silicon nitride layers in CVD processes.

A method of preparing pentachlorodisilane is disclosed. The method comprises partially reducing hexachlorodisilane with a metal hydride compound to give a reaction product comprising pentachlorodisilane. The method further comprises purifying the reaction product to give a purified reaction product comprising the pentachlorodisilane. The purified reaction product comprising pentachlorodisilane formed in accordance with the method is also disclosed.

A method for making chlorinated silazanes. The method comprises contacting: (a) a disilazane; (b) a chlorosilane; and (c) a catalyst which is a zinc salt of: (i) a sulfonic acid or (ii) a sulfonic acid imide.

A method for fabricating trihalodisilane, the method includes providing a halodisilane including at least four halogen atoms; reducing the halodisilane, using a mixed reducing agent including a first reducing agent represented by following Chemical Formula 1-1, in which R.sub.A is an alkyl group, and m and n are each independently 1 or 2, and m+n=3, and a second reducing agent represented by following Chemical Formula 2-1, in which R.sub.S is an alkyl group or an aryl group, p and q are each independently 1, 2, or 3, and p+q=4; and obtaining a product including a 1,1,1-trihalodisilane,

(R.sub.A).sub.m—Al—H.sub.n  [Chemical Formula 1-1]

(R.sub.S).sub.p—Sn—H.sub.q.  [Chemical Formula 2-1]

The content of boron compounds in a composition containing at least one halosilane is reduced by bringing the composition into contact with at least one phenylsilane and removing the at least one halosilane. The invention further relates to the use of phenylsilanes for removing boron compounds from halosilane-containing compositions.

The purpose of the present invention is to produce a high quality hydrogenated polysilane compound by reducing process troubles using the halosilane raw material and the reducing agent.

A method for producing a hydrogenated polysilane compound (CX) of the present invention contains a reducing step (P1) in which a halosilane raw material (C0) selected from a polyhalosilane compound (C1) comprising a Si—Si bond and a Si—X bond (X represents a halogen atom) in the same molecule, a salt of the polyhalosilane compound (C2), and a complex of the polyhalosilane compound (C3) is contacted with a reducing agent (R2) to reduce the halosilane raw material (C0), and a removing step in which a reaction solution of the reducing step (P1) is subjected to one or more steps selected from the following (T1) to (T4) to remove the reducing agent (R2) and/or a resulting material of the reducing agent (R2) contained in the reaction solution. (T1) separating step of a solid and a liquid (T2) separating step of one liquid and another comprising a reaction solution, a concentrated solution of the reaction solution, or a washing solution of the reaction solution or the concentrated solution of the reaction solution (T3) contacting step with an acid aqueous solution (T4) distilling step of the hydrogenated polysilane compound (CX)

A method is useful for preparing partially hydrogenated chlorosilanes by selective hydrogenation with a compound of the formula R.sub.2AlH, wherein R is a branched or cyclic hydrocarbon. Partially hydrogenated chlorosilanes can be prepared with said method, in particular partially hydrogenated chlorosilanes represented by the formula Cl.sub.3SiSi(SiH.sub.3).sub.3, (Cl.sub.3Si).sub.2Si(SiH.sub.3).sub.2 or HSi(SiH.sub.3).sub.2SiCl.sub.3.

A method of preparing pentachlorodisilane is disclosed. The method comprises partially reducing hexachlorodisilane with a metal hydride compound to give a reaction product comprising pentachlorodisilane. The method further comprises purifying the reaction product to give a purified reaction product comprising the pentachlorodisilane. The purified reaction product comprising pentachlorodisilane formed in accordance with the method is also disclosed.

A method for producing purified chlorosilanes includes bringing crude chlorosilanes, such as crude trichlorosilane and crude silicon tetrachloride, which contain a boron compound and/or a phosphorus compound, into contact with chlorine (preferably 1 ppm mole to 3000 ppm mole with respect to 1 mole of crude chlorosilanes) in presence of alkylphenol such as 2-methylphenol, and then distilling the crude chlorosilanes.

A method for making chlorinated silazanes. The method comprises contacting: (a) a disilazane; (b) a chlorosilane; and (c) a catalyst which is a zinc salt of: (i) a sulfonic acid or (ii) a sulfonic acid imide.