Peter R. Keswick

Introduction of a new high-density plasma reactor concept for high-aspect-ratio oxide etching

ULSI oxide etch requirements present a fundamental challenge which cannot be easily overcome with existing oxide etch technology. The principal issue is to provide a wide process window which simultaneously provides; high etch rate with good uniformity, high selectivity with minimal microloading, anisotropic profiles on high aspect ratio structures and all achieved under low damage etch conditions free of device degradation. This paper introduces an innovative application of inductively coupled rf technology which demonstrates a low pressure high density plasma (HDP) etch process, capable of meeting the oxide etch requirements of 0.35 micrometers device technology and beyond. Evidence is also provided of a newly characterized low fluorine polymer (LFP), which forms during the etch process providing anisotropic profiles on high aspect ratio structures and selectivity to a range of substrate materials.