High-yield synthesis of higher germanes and higher silanes includes the hydrolysis of a germanium- or silicon-containing alloy with chemical formula A.sub.xB.sub.yGe(Si), wherein A=Mg, Ca, Sr, Ba, Li, Na, K, Rb, Cs, and rare earth metals; B=Al, Si, Sn, Ga, Zn, Fe, Co, Ni, Cu, Ag; x=0-10, y=0-10. The hydrolysis reaction is promoted by an acidic substance such as boron oxide (B.sub.2O.sub.3), citric acid, hydrochloric acid (HCl), or sulfuric acid (H.sub.2SO.sub.4). The present invention provides an efficient method of drying higher germanes and higher silanes to prevent their further hydrolysis. Another synthetic process involves the reaction of germanium oxide, borohydride and boron oxide with water. Still another process comprises hydrolyzing the Si.sub.1-xGe.sub.x alloy with a very dilute base solution. The methods enable production of higher germanes from a wide range of germanium-starting materials, including germanium byproducts, impure germanium compounds, and waste products generated in the plasma deposition of thin films containing germanium.

High-yield synthesis of higher germanes and higher silanes includes the hydrolysis of a germanium- or silicon-containing alloy with chemical formula A.sub.xB.sub.yGe(Si), wherein A=Mg, Ca, Sr, Ba, Li, Na, K, Rb, Cs, and rare earth metals; B=Al, Si, Sn, Ga, Zn, Fe, Co, Ni, Cu, Ag; x=0-10, y=0-10. The hydrolysis reaction is promoted by an acidic substance such as boron oxide (B.sub.2O.sub.3), citric acid, hydrochloric acid (HCl), or sulfuric acid (H.sub.2SO.sub.4). The present invention provides an efficient method of drying higher germanes and higher silanes to prevent their further hydrolysis. Another synthetic process involves the reaction of germanium oxide, borohydride and boron oxide with water. Still another process comprises hydrolyzing the Si.sub.1-xGe.sub.x alloy with a very dilute base solution. The methods enable production of higher germanes from a wide range of germanium-starting materials, including germanium byproducts, impure germanium compounds, and waste products generated in the plasma deposition of thin films containing germanium.

Methods of selectively synthesizing n-tetrasilane are disclosed. N-tetrasilane is prepared by pyrolysis of silane (SiH.sub.4), disilane (Si.sub.2H.sub.6), trisilane (Si.sub.3H.sub.8), or mixtures thereof. More particularly, the disclosed synthesis methods tune and optimize the n-tetrasilane:i-tetrasilane isomer ratio. The isomer ratio may be optimized by selection of process parameters, such as temperature, residence time, and the relative amount of starting compounds. The disclosed synthesis methods allow facile preparation of n-tetrasilane.

Methods of selectively synthesizing n-tetrasilane are disclosed. N-tetrasilane is prepared by pyrolysis of silane (SiH.sub.4), disilane (Si.sub.2H.sub.6), trisilane (Si.sub.3H.sub.8), or mixtures thereof. More particularly, the disclosed synthesis methods tune and optimize the n-tetrasilane:i-tetrasilane isomer ratio. The isomer ratio may be optimized by selection of process parameters, such as temperature, residence time, and the relative amount of starting compounds. The disclosed synthesis methods allow facile preparation of n-tetrasilane.

A high-purity n-tetrasilane purification method includes: introducing a tetrasilane (Si.sub.4H.sub.10) isomeric mixture into a solidifying purification tank, cooling the tetrasilane (Si.sub.4H.sub.10) to a predetermined temperature with refrigerant in the solidifying purification tank, maintaining the predetermined temperature between the freezing temperature of the n-tetrasilane (n-Si.sub.4H.sub.10) and of the i-tetrasilane (i-Si.sub.4H.sub.10), solidifying the n-tetrasilane (n-Si.sub.4H.sub.10) in the tetrasilane (Si.sub.4H.sub.10) isomeric mixture into solid state, and vacuuming the i-tetrasilane (i-Si.sub.4H.sub.10) from the mixture for separation.

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)

Deposition methods may prevent or reduce crystallization of silicon in a deposited amorphous silicon film that may occur after annealing at high temperatures. The crystallization of silicon may be prevented by doping the silicon with an element. The element may be boron, carbon, or phosphorous. Doping above a certain concentration for the element prevents substantial crystallization at high temperatures and for durations at or greater than 30 minutes. Methods and devices are described.

Synthesis of silanes with more than three silicon atoms are disclosed (i.e., Si.sub.nH.sub.(2n+2) with n=4-100). More particularly, the disclosed synthesis methods tune and optimize the isomer ratio by selection of process parameters such as temperature, residence time, and the relative amount of starting compounds, as well as selection of proper catalyst. The disclosed synthesis methods allow facile preparation of silanes containing more than three silicon atoms and particularly, the silanes containing preferably one major isomer. The pure isomers and isomer enriched mixtures are prepared by catalytic transformation of silane (SiH.sub.4), disilane (Si.sub.2H.sub.6), trisilane (Si.sub.3H.sub.8), and mixtures thereof.

Synthesis of silanes with more than three silicon atoms are disclosed (i.e., Si.sub.nH.sub.(2n+2) with n=4-100). More particularly, the disclosed synthesis methods tune and optimize the isomer ratio by selection of process parameters such as temperature, residence time, and the relative amount of starting compounds, as well as selection of proper catalyst. The disclosed synthesis methods allow facile preparation of silanes containing more than three silicon atoms and particularly, the silanes containing preferably one major isomer. The pure isomers and isomer enriched mixtures are prepared by catalytic transformation of silane (SiH.sub.4), disilane (Si.sub.2H.sub.6), trisilane (Si.sub.3H.sub.8), and mixtures thereof.

Methods of selectively synthesizing n-tetrasilane are disclosed. N-tetrasilane is prepared by catalysis of silane (SiH.sub.4), disilane (Si.sub.2H.sub.6), trisilane (Si.sub.3H.sub.8), or mixtures thereof. More particularly, the disclosed synthesis methods tune and optimize the n-tetrasilane:i-tetrasilane isomer ratio. The isomer ratio may be optimized by selection of process parameters, such as temperature and the relative amount of starting compounds, as well as selection of proper catalyst. The disclosed synthesis methods allow facile preparation of n-tetrasilane.