Etching characteristics of multiple U-type internal linear inductively coupled plasma for flat panel display

In this study, internal type antennas such as a multiple U-type antenna and a serpentine-type antenna were used for the large area (1020 mm×830 mm) inductively coupled plasma (ICP) source and their plasma characteristics of Ar were investigated. In addition, using the multiple U-type antenna, the etching characteristics such as etch rates and etch uniformities of photoresist on the large area substrate (880 mm × 660 mm) were investigated using O2 plasma. The multiple U-type showed about 25% higher plasma density compared to the serpentine-type antenna due to the shorter antenna length and higher inductive coupling. The plasma density obtained with the multiple U-type antenna was about 2×1011 /cm3 at 5000 W of RF power and 15 mTorr Ar. When photoresist was etched using the multiple U-type antenna, the etch rate of about 5385 Å/min with the etch uniformity of 7% on the substrate area could be obtained using 15 mTorr O2, 5000 W of RF power, and − 100 V of dc bias voltage.