Radio-frequency plasma ignition study in a plasma enhanced chemical vapor deposition chamber

Plasma ignition is commonly described by the Paschen equation that approximates the electron avalanche process for a constant electric field generated by a direct current (DC) power supply. In plasma enhanced chemical vapor deposition (PECVD) chambers, DC power supplies are not used since dielectric materials separate the electrodes, and a radio-frequency (RF) power supply is preferred. Ignition voltage with an RF power supply can deviate from that predicted by the DC theory. In this presentation, we provide the ignition voltage for an RF power supply as well as the time to ignite plasma in a PECVD chamber for argon, nitrogen, and oxygen gases at pressures ranging from 2 Torr to 10 Torr. The method to measure the ignition characteristics and comparison against theoretical predictions are discussed.