Abstract: A method of depositing a gallium nitride-based III-V Group compound semiconductor crystal layer over a substrate by a metalorganic chemical vapor deposition technique. A reaction gas is supplied to a surface of a heated substrate in a direction parallel or oblique to the substrate. The gallium nitride-based III-V Group compound semiconductor crystal layer is grown on the heated substrate, while introducing a pressing gas substantially in a vertical direction toward the substrate to press the reaction gas against the entire surface of the substrate, under atmospheric pressure or a higher pressure.

Abstract: A method of manufacture of pitch-based carbon fiber by infusibilization of pitch fiber followed by carbonization, comprising doping the pitch fiber with at least 0.05 percent by weight of iodine, heating under an oxidizing atmosphere for infusibilization, and then heating under an inert atmosphere for carbonization, whereby it is carbonized or graphitized.