Patent ID: 7648895

Claim:
A vertical CVD method for processing a plurality of target substrates all together to form a silicon germanium film, the method comprising: placing a holder in a process field within a reaction container, the holder holding the target substrates stacked at intervals; and forming a silicon germanium film by CVD on the target substrates within the process field, while setting the process field at a first temperature and a first pressure, and supplying a first process gas of a silane family and a second process gas of a germane family into the process field, wherein said forming a silicon germanium film comprises preparing a plurality of mixture gases with different ratios of the first process gas relative to the second process gas by mixing the first and second process gases, supplying the plurality of mixture gases into the process field respectively through a plurality of supply ports disposed at different heights inside the reaction container such that the ratios of the plurality of mixture gases are lower as the supply ports are high in position, and exhausting gas upward from the process field.