Chemical vapor deposition

Claim 1

A reactor for producing a material from first and second gaseous precursors by metal organic chemical vapour deposition which reactor comprises: (i) a reaction chamber for accommodating a heated substrate having a surface upon which said material is to be deposited by reaction of said precursors. (ii) a first chamber for the first precursor, (iii) a second chamber for the second precursor, (iv) a plurality of first conduits connecting the first chamber with outlets in the reaction chamber to provide discrete paths along which the first precursor can pass to the reaction chamber, (v) a plurality of second conduits connecting the second chamber with outlets in the reaction chamber to provide discrete paths along which the second precursor can pass to the reaction chamber whereby contact between said first and second precursors does not occur until the precursors enter the reaction chamber the outlets of the first and second conduits being uniformly distributed so that the outlet of each first conduit is surrounded by the outlets of several of the second conduits and vice versa, and (vi) a means for cooling said first and second conduits and comprising a coolant chamber through which the first and second conduits pass, the first and second conduits being disposed so that the first and second precursors enter the reaction chamber perpendicularly to the substrate surface, and the reactor including exhaust means causing the precursors to flow along the substrate surface when being exhausted from the reaction chamber.