Journal of Vacuum Science & Technology B, Vol.15, No.3, 675-680, 1997
New Metal Etching Method for Reducing Electron Shading Damage
This study proposes a new metal etching method for reducing electron shading damage using an inductively coupled plasma (ICP) etcher. Electron shading damage is caused by the same mechanism as in "notch" formation. Namely, negative charge-up of the sidewall of the photoresist by electrons due to the difference between electron and ion motion in the plasmas : We can therefore assume that an etching process with no notch will have low electron shading damage. The notch-free overetching process using low inductive power in an ICP etcher was found to have low and uniform electron shading damage. We also present an evaluation method for electron shading damage using a metal-nitride-oxide-silicon capacitor with a comblike antenna.