Plasma CVD apparatus and method for manufacturing membrane

摘要

PROBLEM TO BE SOLVED: To facilitate retention of plasma even when frequency of a high-frequency output is decreased.SOLUTION: A plasma CVD apparatus comprises a chamber 1, a substrate holder 3 arranged in the chamber and holding a substrate 2, a gas introduction passage connected to the chamber for introduction of a raw material into the chamber and an output supply mechanism supplying a high-frequency output of 5-500 kHz into the chamber in the form of pulses of a cycle of 0.02-20 ms and a DUTY ratio of 10-90%, where the DUTY ratio is a ratio of the period in which the high-frequency output is applied to the substrate holder in one cycle. A film is formed on the substrate by generating plasma in the chamber by the high-frequency output supplied by the output supply mechanism.