CHEMICAL-VAPOR DEPOSITION FILM FORMING DEVICE

PROBLEM TO BE SOLVED: To provide a chemical-vapor growth film forming device, wherein CVD(chemical vapor deposition) films having the same film thickness and film quality are formed on three or more wafers. SOLUTION: This LPCVD pressure-reduced chemical vapor deposition) device has a longitudinal quartz boat 40, which holds and mounts three or more wafers in parallel horizontally at a wafer peripheral part, a process chamber for containing the quartz boat 40, and a gas inlet injector 20, which introduces raw material gas into the lower part of the process chamber. The raw-material gas is made to flow in the process chamber from the lower end to the upper end of the quartz boat 40, and the CVD film is formed on the wafer surface by the chemical vapor deposition method. The quartz boat 40 is formed so as to hold the wafers such that the interval between the wafers becomes larger stepwise from the lower end to the upper end of the quartz boat 40. Thus, the quantity of the raw-material gas molecules supplied to the wafers can be made uniform, and the uniformity of the film thickness and the film quantity among the wafers can be improved.