Scalable internal linear double comb-type inductively coupled plasma source for large area flat panel display processing

The characteristics of a large area internal linear inductively coupled plasma source of 2750 mm × 2350 mm have been studied using a linear antenna with a double comb-type parallel connection. Using the ICP with the double comb-type linear antenna, a plasma density of 8 × 1010/cm3 and a power transfer efficiency of approximately 82% could be obtained at about 10 kW of rf power and with 5 mTorr Ar. Low plasma potentials and low electron temperatures decreasing from 45 to 20 V and from 3.33 to 2.78 eV, respectively, could be obtained as the operation pressure was increased from 5 to 20 mTorr at 10 kW of rf power. The measured plasma uniformity on the substrate size of 7th generation (2300 mm × 2000 mm) at 5 kW of rf power and with 15 mTorr Ar was approximately 14% and the photoresist etch uniformity measured using 15 mTorr Ar/O2(7:3) at 8 kW of rf power was about 12.5%. Therefore, it is believed that the double comb-type parallel connection can be successfully applicable to the large area flat panel display processing.