NiCr etching in a reactive gas

Abstract

The authors have etched NiCr through a resist mask using Cl∕Ar based chemistry in an electron cyclotron resonance etch system. The optimum gas mixture and etch parameters were found for various ratios of Ni to Cr, based on the etch rate, redeposits, and the etch ratio to the mask. The introduction of O2 into the chamber, which is often used in the etching of Cr, served to both increase and decrease the etch rate depending explicitly on the etching parameters. Etch rates of >50nmmin−1 and ratios of >1 (NiCr:Mask) were achieved for NiCr (80:20). Pattern transfer from the mask into the NiCr was achieved with a high fidelity and without redeposits for a Cl∕Ar mix of 10% Ar (90%Cl2) at an etch rate of ≈50nmmin−1 and a ratio of 0.42 (NiCr:ZEP 7000 e-beam mask).