Abstract: A cold wall type CVD apparatus that can enhance a raw material yield is provided. The CVD apparatus has a raw material gas jetting unit 11 for jetting raw material gas, a susceptor 14 for supporting a tape-shaped base material T and heating the tape-shaped base material T through heat transfer, a heater 15 for heating the susceptor 14, an inert gas introducing unit 12a for introducing inert gas to suppress the contact between the heater and the raw material gas, and a raw material gas transport passage LG for guiding the raw material gas jetted from the raw material gas jetting unit 11 to the surface of the tape-shaped base material.

Abstract: Doped thin films of GaAs are chemically vapor deposited by depositing a high resistant buffer layer of GaAs on a GaAs substrate by gaseous reaction of a mixture of arsine gas and trimethylgallium in the gas phase over the substrate while the temperature of the substrate is maintained within the range of 600.degree.-700.degree. C., stopping the supply of trimethylgallium to the gas mixture undergoing reaction and increasing the temperature of the substrate to within the range of 700.degree.-800.degree. C., and then resuming the supply of trimethylgallium to and supplying hydrogen sulfide to the gas phase over the substrate at the stated temperature, thereby depositing a doped GaAs layer over the buffer layer on the substrate having a distribution of carrier density of less than 5%.

Abstract: A vapor phase deposition method for the GaAs thin film is disclosed, which is characterized in that, in the metal organic chemical vapor deposition method (MOCVD method) wherein arsine gas and organic gallium gas are decomposed thermally and GaAs crystals are allowed to deposit onto the GaAs substrate, for the deposition of n-type conductive GaAs crystals, arsine gas and organic gallium gas are supplied at such a supplying ratio (V/III) as p-type conductive GaAs crystals are deposited unless an impurity is added intentionally and gas of the compounds of VI group elements is added to these gases to make n-type conductive GaAs crystals having a carrier density of not less than 1.times.10.sup.16 cm.sup.-3.

Abstract: A chemical vapor deposition method for making a semiconductor thin film is disclosed, which is characterized in that, in the method wherein semiconductor thin films are allowed to deposit onto the substrates by allowing the susceptor in the shape of polygonal frustum fitted with a plurality of semicondutor substrates to the side faces thereof to rotate in the vertical type reaction tube, by introducing the source gases and the carrier gas into the tube, and by heating the substrates to allow the source gases to react through thermal decomposition, the number of rotations of susceptor is varied in terms of rectangular wave function, trapezoidal wave function or sine wave function and the susceptor is allowed to rotate in converse directions depending on the positive region and the negative region of the function.