Micro-arcing instability in RF PECVD plasma system

Abstract

Microarcing at the chamber wall in RF plasma is studied in PECVD type system. A Langmuir probe is used to measure the plasma potential. This system and procedure allows us to create reproducibly microarcings by increasing the plasma potential. The wall arcing threshold of the plasma potential in this system is in the vicinity of 50 V. In this system, the charging process, which is about a few tens of milliseconds or more, is much slower compared to the microsecond discharge. The time constant for sheath charging can be reduced if less sheath area is responsible for the potential recovery. The arcing frequency strongly depends on the plasma potential, the grounded surface area of sheath, and the pressure. This work demonstrated that the microarcing in the RF deposition and reactive etching plasmas depends on plasma potential, gas pressure, surface area of grounded wall, and chamber conditions. Show more