Reactive ion etch of 150 nm Al lines for interconnections in dynamic random access memory

Three different manufacturable alumina etch processes were developed for 175/175 and 150/150 nm line/space structures. It was shown that the reactive ion etching (RIE) process can clear a sub-100 nm space for metal stacks having a height of 435 nm. This indicates that aluminum RIE can be extended for even smaller structures without requiring a new generation of the tool set.