AVS 56th International Symposium & Exhibition
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP15
Amorphous Silicon Etching Using Atmospheric-Pressure Dielectric Barrier Discharge (APDBD) Plasma

Tuesday, November 10, 2009, 6:00 pm, Room Hall 3

Session: Plasma Science and Technology Poster Session
Presenter: H.C. Kwon, Seoul National University, Korea
Authors: H.C. Kwon, Seoul National University, Korea
G.H. Kim, Seoul National University, Korea
S.H. Lee, Korea Institute of Materials Science, Korea
T.H. Noh, National Fusion Research Institute, Korea
S.I. Choi, Samsung Electronics Co. Ltd, Korea
S.G. Kim, Samsung Electronics Co. Ltd, Korea
S.K. Lim, Samsung Electronics Co. Ltd, Korea
Correspondent: Click to Email
Since the process area has been enlarged for increasing the fabrication rate of TFT-LCD, the atmospheric process has been attractively considered. Among the atmospheric processes, the etching is the most challengeable due to the difficulty of etch pattern control and charge damage. Here the etch properties of atmospheric-pressure dielectric barrier discharge (APDBD) has been investigated for the system size of 300 mm × 80 mm. The etching process has been accomplished at 2~3 mm below a blower type APDBD which is a closed system consisted of the top and bottom dielectric electrodes to generate the DBD plasma. Thus, the introduced etchants (SF6) with carrier gas (N2) are discharged in the DBD source chamber and the radicals are extruded through the hole of DBD source into the target of amorphous silicon (a-Si) on the patterned silicon nitride (SiNx) with photoresist (PR). The target is set on the moving stage with maximum speed of 100 mm/s. Thus the charge damage may not be considered in this etching system. The etch profiles were exampled with AFM, SEM and others. Result shows the availability of a few micron patterns and etch rate of 600 Å/min with the uniformity below 10% over the substrate. The etch rate and uniformity are sensitive to gas flow rate, the gas mixing ratio, the substrate temperature and the substrate motion. The electrical and optical methods were employed to monitor the discharge properties as the plasma density and gas temperature in source chamber, respectively. Tentatively, it concluded that the ATM process has the property in between the wet and dry (vacuum) process due to its highly collisional condition. The radical generation and transport in the system play a key role in improve the etching, which will be presented.