Abstract: As to technical subject matters of attempting increase of deposition rate and improvement of film quality and removing restriction of light source and source gas in the photo CVD process, the promotion of photolysis of the source gas is achieved by use of a pulse laser beam together with a continuous light, application of plural laser beams wherein each pulse of at least one second pulse laser beam is irradiated into each interval between a pulse and the next pulse in a first lase beam, and further introduction of an additive gas in addition to the source gas into a reaction vessel and particularly the provision of photo CVD process advantageously adaptable for the production of semiconductor is realized.

Abstract: An apparatus for forming, by a chemical vapor deposition process, a thin film of crystals such as diamond on a surface of a heated substrate placed in a reaction vessel. The apparatus has a substrate supporting structure, a heater for heating the substrate by heat conduction or by electric current supplied directly to the substrate, and a cooling device for cooling the substrate. The heater is controlled in accordance with the measured temperature of the substrate so as to accurately maintain the substrate temperature at a constant level.

Abstract: An apparatus for forming, by a chemical vapor deposition process, a thin film of crystals such as diamond on a surface of a heated substrate placed in a reaction vessel. The apparatus has a substrate supporting structure, a heater for heating the substrate by heat conduction or by electric current supplied directly to the substrate, and a cooling device for cooling the substrate. The heater is controlled in accordance with the measured temperature of the substrate so as to accurately maintain the substrate temperature at a constant level.