Vertical Platinum Etch Profile for Electrode of High-K Dielectric Materials with Cl2/Ar/C4F8 Plasma

초록

In this paper, we investigate the characteristics of the platinum dry etch using Cl2/Ar/C4F8 gas with ICP(Inductively Coupled Plasma) source. Platinum is widely used as electrode of high-k dielectric materials and the vertical side wall slope of electrode is important especially in the fine pattern process for ultra large scale integration. The etch selectivity of platinum to photoresist is improved from 1:1 to 1.6:1 by C4F8 gas addition to Cl2/Ar gas and this leads to very anisotropic Pt sidewall etch angle of 80 even with the photoresist masking. We studied the C4F8 addition effect by monitoring the variation of active plasma species with QMA(Quadruple Mass Analyzer) and analyzing the residue of etched surface.