Large area deposition technique of magnesium oxide thin film for plasma display panel applications

摘要

A higher rate deposition sputtering process of magnesium oxide thin film in oxide mode has been developed using a 20 kW unipolar pulsed power supply. The power supply was operated at a maximum constant voltage of 500 V and a constant current of 40 A. The frequency and the duty were changed in the ranges of 10 ~ 50 kHz and 10 ~ 60 %, respectively. The deposition rate increased with increasing incident power to the target. Maximum incident power to the magnesium target was obtained by the control of frequency, duty and current. The deposition rate of a moving state was 9 nm m/min at the average power of 1.5 kW. This result shows higher deposition rate than any other previous work of reactive sputtering at the oxide mode. The thickness uniformities over the whole substrate area of 982 mm x 563 mm were observed at the processing pressure of 2.8 ~ 9.5 mTorr. The thickness distribution was improved at lower pressure.