Qualitative measurement of the ICP plasma sheath driven by high voltage pulse

• Main Authors: C. S. Lin, 林俊旭
• Other Authors: Chwung-Shan Kou
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/65104683441667993668

碩士 === 國立清華大學 === 物理學系 === 88 === Using the "two-dimensional nonlocal heating theory",which was developped by N. S. Yoon, to design the planar-type coil of the planar-type ICP(inductively coupled plasma) system. And we successfully set a planar-type ICP system. We observe that during the E-H transition, plasma potential has apparent change,just like Sang-Hun Seo's observation. Generally speaking,ion current density exponentially decrease with the height. We measure the plasma sheath propagation under -2kV voltage pulse and the current on the electrode. The current includes displacement current, ion current, electron current, and secondary electron emission. We often want to subtract the displacement current and the secondary electron emission current. If we measure the displacement current without plasma and subtract it from the current measured when plasma was on, there will be inaccuracy. It's because the pulse waveform were different in two conditions. We can use the equation I=C*dV/dt to compute the correct displacement current,where C is the capacitance between the electrode and the vacuum chamber. To compare the ion current density dritribution and the sheath propagation velocity, the result is reasonable.