ASPECT RATIO INDEPENDENT ETCHING OF DIELECTRICS

Monte Carlo simulations of pattern-dependent charging during oxide etc hing predict that the etch rate scaling with aspect ratio breaks down when surface discharge currents are significant. Under conditions of i on-limited etching and no inhibitor deposition, the etch depth depends on the maximum incident ion energy, reaction threshold, and surface d ischarge threshold, and is the same irrespective of the trench width ( less than or equal to 0.5 mu m). (C) 1997 American Institute of Physic s.