抄録
Reactive ion etching (RIE) systems using capacitively coupled plasma (CCP) and inductively coupled plasma (ICP) sources with SF6 gas have been developed for deep silicon machining with high aspect ratio. The developed RIE systems demonstrated high etch rate (2.3μm/min) and high selectivity (1700) for a sputtered nickel mask in silicon etching. A large capacity turbo molecular pump (TMP) with a small etching chamber was used to realize a low pressure with a high flow rate of etching gas. A circulatory cooling apparatus was used for cooling a silicon wafer. Etch rate showed uniformity within 10% for the area of 50cm2. Using the RIE system, we succeeded to etch a 200μm thick silicon wafer vertically through the thickness with an aspect ratio greater than 10. The RIE can be applied to fabricate three-dimensional silicon microstructures.
