Patent attributes
A plasma processing apparatus can efficiently perform a pulse modulation method of switching a high frequency power to be used in a plasma process between a high level and a low level alternately according to a duty ratio of a modulation pulse. In this plasma processing apparatus, when performing a high/low pulse modulation on the high frequency power for plasma generation, if a weighted variable K is set to be 0.5<K<1, a constant reflection wave power PRH is generated on a high frequency transmission line of a plasma generation system even during a pulse-on period Ton. Meanwhile, during a pulse-off period Toff, a reflection wave power PRL decreases. By adjusting the value of K, a balance between the reflection wave power PRH during the pulse-on period Ton and the reflection wave power PRL during the pulse-off period Toff can be controlled.
