| AVS 55th International Symposium & Exhibition | |
| Plasma Science and Technology | Wednesday Sessions |
| Session PS2-WeA |
| Session: | Plasma Diagnostics, Sensors, and Control I |
| Presenter: | L. Meng, University of Illinois at Urbana-Champaign |
| Authors: | L. Meng, University of Illinois at Urbana-Champaign R. Raju, University of Illinois at Urbana-Champaign T. Dockstader, Kurt J Lesker Company H. Shin, University of Illinois at Urbana-Champaign D.N. Ruzic, University of Illinois at Urbana-Champaign |
| Correspondent: | Click to Email |
Since the demand keeps growing for larger size plasma displays, and for inexpensive flexible displays on plastic or other organic substrates, it is important to develop a plasma processing device to handle large size substrates, while maintain the uniformity and quality of deposited materials without damaging the substrate. An RF plasma-assisted closed-field dual magnetron sputtering system investigated in this study is the prototype of such a system. The prototype consists of two 3 inch DC magnetrons which can be operated at both balanced and un-balanced (closed-field) configurations. This system enhances the plasma density, metal ionization fraction and has the ability to produce high quality films at lower substrate temperature. An RF coil was fabricated, installed in between the magnetrons to initiate secondary plasma. A RF compensated Langmuir probe was used to diagnose the spatial distribution of argon sputtering plasma. In the constant current mode (50 mA) of the magnetrons, the RF plasma enhances the electron density to one-order of magnitude higher compared with no RF plasma and results in an increase in the deposition rate. The ionization fraction of the sputtered materials was measured using the QCM combined with electrostatic filters. The presence of RF plasma effectively enhanced the ionization fraction of the sputtered metal flux to about 90%. The performance of the closed-field magnetron configuration was compared with the balanced one. Enhancement in the electron density is observed in the closed-field magnetron configuration near the substrate which is twice as large compared to the balanced one. Experiments were conducted on the deposition of ITO on glass and plastic substrates at closed-field configuration. Wide range of operating parameters has been investigated to get highly transparent and conducting films. ITO thin film with 91% of transparency and resistivity of 30 Ω/square was obtained at the magnetron current of 90 mA, pressure of 5 mTorr, 2.5% of O2 fraction in Ar, the RF power of 225 W, and substrate temperature was well kept below 120 °C. Results on the optimization of the operating parameters for high quality ITO film will be presented. Surface morphological studies have been carried out on the film using both balanced and un-balanced configurations. Results from extending this system to larger rectangular shaped magnetrons in a real flat panel display manufacturing system will also be presented.