Plasma-CVD method and apparatus

Abstract

In a plasma-CVD method and apparatus, plasma is formed from a film material gas in a process chamber and, in the plasma, a film is deposited on a substrate disposed in the process chamber. Formation of the plasma from the material gas is performed by application of an rf-power prepared by effecting an amplitude modulation on a basic rf-power having a frequency in a range from 10 MHz to 200 MHz. A modulation frequency of the amplitude modulation is in a range from 1/1000 to 1/10 of the frequency of the basic rf-power. Alternatively, the rf-power is prepared by effecting on the basic rf-power a first amplitude modulation at a frequency in a range from 1/1000 to 1/10 of the frequency of the basic rf-power, and additionally effecting a second amplitude modulation on the modulated rf-power. A modulation frequency of the second amplitude modulation is in a range from 1/100 to 100 times the modulation frequency of the first amplitude modulation.

Dependencies are inferred from the claim text.