Production of a large diameter ECR plasma for plasma processing
  A large diameter plasma over 300 mm in diameter is produced by electron cyclotron resonance (ECR) discharges using a newly developed large diameter chamber of 400 mm in inner diameter. It is found that the electron temperature decreases as nitrogen gas is added to pure argon plasma, which is considered that nitrogen molecules absorb the electron energy into the vibrational energy and lead to the decrease of the electron temperature. Moreover, it is found that the plasma uniformity is improved by adding nitrogen gas, suggesting that the adjunction of nitrogen gas is effective for producing uniform and low electron temperature plasma. 
Mayuko Koga, Yasuhiro Hishikawa, Hayato Tsuchiya, Yoshinobu Kawai