Patent ID: 8872427

Claim:
A plasma generating apparatus for generating a plasma in each of N vacuum chambers, where N is an integer not smaller than 2, by applying voltage between vacuum chamber walls of said N vacuum chambers, and N electrodes, one of said N electrodes disposed in each of said N vacuum chambers, comprising: a direct-current power supply, an electrode of the direct-current power supply being connected to said vacuum chamber walls; an oscillator which outputs a pulse signal at every predetermined period; N pulse amplifying circuits which are connected in parallel to said oscillator as well as to the other electrode of said direct-current power supply, and each of which amplifies said pulse signal to obtain a direct-current pulse signal by using power supplied from said direct-current power supply and supplies said direct-current pulse signal to a corresponding one of said N electrodes; and at least (N-1) timing generating circuits which are connected between said oscillator and at least (N-1) pulse amplifying circuits selected from among said N pulse amplifying circuits, and which delay said pulse signal by respectively different delay times so that during a period when said pulse signal is supplied to one of said N pulse amplifying circuits, said pulse signal is not supplied to any one of the other pulse amplifying circuits, wherein said oscillator outputs as said pulse signal a signal that contains a short pulse that has a first voltage and a first duration and a long pulse that follows said short pulse and that has a second voltage whose magnitude is smaller than said first voltage and a second duration longer than said first duration, and a voltage of said direct-current pulse signal during a period corresponding to said short pulse makes a glow discharge occur in said vacuum chambers, while a voltage of said direct-current pulse signal during a period corresponding to said long pulse makes the glow discharge be sustained and prevents an arc discharge from occurring in said vacuum chambers.