Effect of Addition of Nitrogen to a Capacitively Radio-Frequency Hydrogen Discharge

• Published in: Plasma science & technology 2014-03, Vol.16 (3), p.203-210
• Main Author: 张连珠 姚福宝 赵国明） 郝莹莹 孙倩
• Format: Article
• Language: English
• Subjects: Charged particles; Computer simulation; Density; Electric discharges; Electric fields; Electrodes; Energy of dissociation; Ionization; Sheaths; 容性; 射频放电; 平均能量; 氢离子浓度; 氮气; 电场分布; 电子碰撞电离; 等离子体过程
• ISSN: 1009-0630
• DOI: 10.1088/1009-0630/16/3/06

A hybrid PIC/MC model is developed in this work for H2-xN2 capacitively coupled radio-frequency （CCRF） discharges in which we take into account 43 kinds of collisions reaction processes between charged particles （e-, H3＋, H＋, H＋, N＋, N＋） and ground-state molecules （H2, H＋ N2）. In addition, the mean energies and densities of electrons and ions （ 3, H＋, H＋）, and electric field distributions in the H2-N2 CCRF discharge are simulated by this model. Furthermore, the effects of addition of a variable percentage of nitrogen （0-30%） into the H2 discharge on the plasma processes and discharge characteristics are studied. It is shown that by increasing the percentage of nitrogen added to the system, the RF sheath thickness will narrow, the sheath electric field will be enhanced, and the mean energy of hydrogen ions impacting the electrodes will be increased. Because the electron impact ionization and dissociative ionization rates increase when N2 is added to the system, the electron mean density will increase while the electron mean energy and hydrogen ion density near the electrodes will decrease. This work aims to provide a theoretical basis for experimental studies and technological developments with regard to H2-N2 CCRF plasmas.