Large Area High Density Plasma Source by Helical Resonator Arrays

초록

An array of smaller unit plasma sources have been be used for generating larger area plasma to process large substrates such as flat panel display(FPD). In this work, four helical resonators are distrubuted in a 2x2 array by modifying upper part of the conventional reactive ion etching (RIE) type LCD etcher. Since the resonance condition of the individual unit can be easily found by adjusting the tapping position of RF signal to the helical antenna, one RF power supply is used for delivering the power efficiently to all four helical resonators without an impedance matching network. Previous work of 2x2 array inductively coupled plasma (ICP) requires one matching circuit to each ICP antenna for more efficient power delivery. Distributions of ion density and electron temperature are measured in terms of chamber pressure, gas flow rate and RF power. By adjusting the power distribution among the four helical resonator units, argon plasma density of highter than 10^16/m3 with the uniformity of better than 7% can be obtained in the 620x620mm2 chamber.