Etching characteristics of magnetic materials (Co, Fe, Ni) using CO/NH3 gas plasma for hardening mask etching

CO+NH3 plasma etching for magnetic thin films

“…Ta and Ti films showed lower etch rates at higher bias power density. Thus, selectivity of Ni-Fe to Ti or Ta was about 7, which was slightly lower than the previous result [2]. Fig.…”

“…The maximum rate of the Ni-Fe film was 127 nm/min at bias power of 2.5 W/cm 2 . The etch rate value was as high as the previous result[2], but obtained at lower bias powerARTICLE IN PRESS *Corresponding author. Tel.…”

“…Shape, magnetic and electrical properties of very small magnetic elements and homogeneity of those properties over a large size wafer would not be controlled fully by conventional Ar ion etching. Reactive ion etching using CO-based gas [1][2][3] or chlorine-based gas [4] has been studied for Ni-Fe and other magnetic metals. CO is expected to react with Ni or Fe, forming volatile metal carbonyls such as Ni(CO) 4 or Fe(CO) 5 .…”

“…Etch rates of Ni-Fe thin films up to 130 nm/ min have been reported using CO plasma with NH 3 gas. However, physical sputtering was considered to be a main component in the experiment [2]. In this study, bias power density dependence and pressure dependence of etch rate of Ni-Fe were investigated using CO+NH 3 mixture with a high-density electron cyclotron resonance (ECR) plasma source.…”

Reactive Ion Etching of NiFe Film with Organic Resist Mask and Metal Mask by Inductively Coupled Plasma

“…However one can not get rid of a degradation of the resultant structure due to residual chlorine and non-volatile products in the Cl 2 -based process. Also the RIE process for etching of NiFe and other magnetic materials were carried out under the CO/ NH 3 discharges [2][3][4]. It was indicated that producing volatile metal carbonyl proceed with the etching of NiFe.…”