Patent ID: 8277893

Claim:
A chemical vapor deposition process for forming a film of a gallium nitride compound semiconductor, comprising: employing a chemical vapor deposition apparatus comprising a susceptor for mounting a substrate thereon, a heater for heating the substrate, a feed gas introduction portion, and a gas exhaust portion for a reaction gas, wherein a light transmitting ceramics plate held or reinforced by means of a supporting member is equipped between the heater and a mounting position of the substrate, the light transmitting ceramics plate being provided by plural sectorial light transmitting ceramics plates, and a gap between each of the plural sectorial light transmitting ceramics plates and the heater is in the range of from 1 to 20 mm, and introducing a feed gas containing ammonium into said chemical vapor deposition apparatus while introducing an inert gas into said gap, wherein said light transmitting ceramics plate is circular or discus, and divided along its radius to provide said plural sectorial light transmitting ceramics plates.