Reactive ion etching lag on high rate oxide etching using high density plasma

In this article, reactive ion etching (RIE) lag effect dependence on total gas flow in contact hole etching is first investigated at a high oxide etch rate using high density plasma. We used surface wave coupled plasma apparatus, which achieves a high density of over 1011 cm−3 and a high oxide etch rate of over 1 μm/min. In the high gas flow etching process, a strong RIE lag is observed. However, the low gas flow etching process suppresses the RIE lag. Total gas flow dominates the RIE-lag effect, and the oxygen of the etching product plays an important role for reducing the RIE-lag effect.