DE1467086C3 - Process for the epitaxial growth of silicon carbide - Google Patents

Description

1 sheet of drawings

Claims (1)

1 2 stab is managed, you get with the AbPatent claim: divorce only a polycrystalline powder that is then by prolonged heating in coarsely crystalline Can transfer method for epitaxial growth of silicon carbide. Silicon carbide on a crystalline seed crystal 5 In attempts to produce single crystals of silicon carbide from silicon carbide by pyrolytic decomposition according to the van Arkel method by decomposing gases containing silicon and carbon gas mixtures on a heated wire or a tube with a main heating, modified by the method (Philips Research Reports, patent 1,467,085, in which a chlorine-free silane, Vol. 18, 1963, pp. 161 to 274), usable results were only achieved with mixtures containing chlorine and aliphatic hydrocarbons. Gas is used, characterized by silane, methane and also monomethyl-silane (SiH ₃ CH ₃ ) distinguishes that monomethyl-silane (SiH ₃ CH ₃ ) was used because of its unfavorable chemical and phy. physical properties no crystal growth. It it was therefore not to be expected that SiH ₃ CH _{3 would be} suitable for epitaxial growth, especially since experiments with similar, but chlorine-containing gals mixtures failed. It was attempted to use cubic silicon carbide on a base of to grow hexagonal silicon carbide. This The invention relates to a method for the epitaxial difference, however, must be viewed as insignificant silicon carbide will grow on a table, since the hexagonal is closest and the cubic crystalline seed crystal made of silicon carbide close to each other through densely packed crystal lattices Pyrolytic decomposition of silicon and carbon are related, especially the atomic distances in containing gases are the same by modifying the two grids. Therefore can a driving according to main patent 1,467,085, in which the substrate of hexagonal SiC is absolutely essential Chlorine-free silanes and aliphatic hydrocarbon layers of either cubic or hexagonal, gas containing substances is used. ■ form epitaxially applied SiC layer. The invention described in the main patent 1 467 085 is based on an execution driving is fraught with the difficulty that silanes are described as an example. In the figure, the reaction vessels used are very easily flammable and in larger quantities 30 reaction vessels are shown graphically,
The reaction vessel 1 is made of quartz and is dangerous due to spontaneous ignition Causes can. Thereby the applicability with the supply lines 6 and 7 and a discharge becomes this Procedure because of the necessary precautionary measures. Inside the reaction vessel 1 is an off measures very difficult. Graphite or tantalum existing block 2 arranged, The object of the invention is therefore to provide a variant on which a silicon carbide single crystal plate 4 lies, To specify the deltes method, in which, as pyrolytic, the induction windings 5, block 2 Substance to be decomposed: a non-self-igniting and the silicon carbide plate on top 4 Connection is used. heated. Line 6 turns a (not According to the invention, in the method of the storage container monomethyl silane described above, this task is _{entered into the reaction vessel 40 (SiH 3} CH ₃ ), which is achieved by _{using monomethyl silane (SiH 3} CH ₃ ) when it hits the heated silicon carbide is, γ single crystal wafer 4 is pyrolytically decomposed. The use of the silicon carbide released in the gas state overlaps on guided monomethylsilane to produce the platelet 4 in the form of an epitaxial layer of pure silicon carbide is known per se. At this -45 from. Doping additives such as chromium, boron, aluminum, processes in which an alkylated silane or a phosphorus, nitrogen, etc., can be mixed in via line 7 alkylated halosilane via a heated silicon.