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Etch Characteristics of CoTb and CoZrNb Thin Films by High Density Plasma Etching  

Shin, Byul (Department of Chemical Engineering, Inha University)
Park, Ik Hyun (Department of Chemical Engineering, Inha University)
Chung, Chee Won (Department of Chemical Engineering, Inha University)
Publication Information
Korean Chemical Engineering Research / v.43, no.4, 2005 , pp. 531-536 More about this Journal
Abstract
Inductively coupled plasma reactive ion etching of CoTb and CoZrNb magnetic materials with the photoresist mask was performed using $Cl_2/Ar$ and $C_2F_6/Ar$ gas mixtures and characterized in terms of etch rate and etch profile. As the concentrations of $Cl_2$ and $C_2F_6$ gases increased, the etch rates of magnetic films decreased and the etch slopes became slanted. The $Cl_2/Ar$ gas was more effective in obtaining fast etch rate and steep sidewall slope than the $C_2F_6/Ar$ gas. As the coil rf power and dc bias increased, fast etch rate and steep etch slope were obtained but the redeposition on the sidewall was observed. This is due to the increase of ion and radical densities in plasma with increasing the coil rf power and the increase of incident ion energy to the substrate with increasing the dc bias voltage. By applying high density reactive ion etching to magnetic tunnel junction stack containing various magnetic films and metal oxide, steep etch slope and clean etch profile without redeposition were obtained.
Keywords
CoTb; CoZrNb; Reactive Ion Etching; Magnetic Tunnel Junction; Inductively Coupled Plasma;
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