| AVS 54th International Symposium | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS1-ThA |
| Session: | Plasma Diagnostics II |
| Presenter: | W.-C. Chen, Academia Sinica, Taiwan |
| Authors: | W.-C. Chen, Academia Sinica, Taiwan C. Mahony, University of Ulster, UK K.-H. Chen, Academia Sinica, Taiwan L.-C. Chen, National Taiwan University |
| Correspondent: | Click to Email |
Here we investigate radio frequency (RF) inductively coupled plasma (ICP) as an in-line sensor for characterizing vertical aligned carbon nanotubes (CNTs) deposition plasma via correlation of the real/imaginary RF current/voltage. The plasma dual directional coupler (PDDC) was used to measure the forward and reflected voltage before the ICP matching network in Ar plasma. Then we introduce a homemade external circuit to give impedance Z, which includes the parasitic inductances of capacitors, parasitic capacitance of inductors and cable resistances. Component values in the circuit model can be determined by analysis of VHF (very high frequency) bridge and spectrum analyzer data. With arising reaction pressure in Ar plasma, the corresponding current & voltage will be change. The maximun current in Ar plasma can be observed at the pressure of 60 mtorr and power of 200 Watt. Indicating much higher electrons density and effective collision frequency in this plasma condition. Measured values of Z with rising RF input power of plasma shows the reactance X to vary from negative to positive values. These correspond with observed E to H transition in this ICP. We will discuss RF harmonics during CNTs deposition condition in Ar & CH4 and relate them to process repeatability and reliability.