| AVS 57th International Symposium & Exhibition | |
| Plasma Science and Technology | Monday Sessions |
| Session PS2-MoA |
| Session: | Atmospheric Plasma Processing and Micro Plasmas |
| Presenter: | Y.J. Yang, National Taiwan University, Taiwan, Republic of China |
| Authors: | Y.J. Yang, National Taiwan University, Taiwan, Republic of China Y.W. Hsu, National Taiwan University, Taiwan, Republic of China Y. Lin, National Taiwan University, Taiwan, Republic of China C.C. Hsu, National Taiwan University, Taiwan, Republic of China |
| Correspondent: | Click to Email |
This presentation includes the diagnostic studies of an atmospheric pressure plasma jet (APPJ) and the use of this plasma jet to perform ZnO thin film deposition. The APPJ under investigation is sustained by a pulsed power supply with a repetitive power frequency up to 25 kHz using N2 or O2 as the plasma gas. The assessment of how the ambient air influences the plasma characteristics and how it can effectively be minimized are the focus of the diagnostic work. To minimize the ambient air influence, the exit of the jet is shielded with a glass tube with the inside diameter ranging from 3 to 5 cm . The exit of the tube is covered by a metal plate and leaving a gap of 0.5 to 3 mm. When the N2 plasma is used, the visible jet length is much longer with such an arrangement. The effective area within which the jet is treated increases by more than a factor of two, as confirmed by the contact angle measurement made on the treated glass surface. In O2 plasmas, the intensity of atomic oxygen emission (777.4 nm) increases by more than one order of magnitude with the presence of the glass tube. When photoresist is etched using this oxygen plasma jet, the jet with the presence of the glass tube shows a increase in the etching rate by more than 50 % than the case without the presence of glass tube.
The use of this APPJ to perform ZnO thin film deposition is studied as the second part of this presentation. ZnO thin films are deposited on a silicon wafer by spraying nebulized zinc-containing salt solutions, namely ZnCl2 and Zn(NO3)2, into the downstream of the plasma jet. Preliminary studies show that by using N2 plasmas, a better quality film can be obtained comparing with using O2 plasmas. The film quality is found to be sensitive to the plasma conditions. With properly adjusted process parameters, dense and smooth films can be deposited with a rate higher than 75 nm/min. Improvement of the electrical conductivity and the study of the photoluminescence properties of the film are currently underway.