Etch characteristics of cobalt thin films using high density plasma of halogen gas

초록

Inductively coupled plasma (ICP) reaction ion etching of Co thin films patterned with SiO 2 hard marks was performed using Cl 2 /Ar and Cl 2 /O 2 /Ar gas mixtures. The etch rate, etch selectivity, and etch profile of the cobalt thin films were investigated by varying the gas concentration in the Cl 2 /Ar and Cl 2 /O 2 /Ar gas mixtures. The etching parameters, including the ICP RF power, DC-bias voltage to the substrate, and process pressure, were varied to investigate the etch characteristics. The etch mechanisms in the Cl 2 /Ar and Cl 2 /O 2 /Ar gas mixtures were examined using X-ray photoelectron spectroscopy, scanning probe microscopy, and optical emission spectroscopy. Finally, the cobalt thin films with 300 nm line pattern were etched using a Cl 2 /O 2 /Ar gas mixture under the optimized etch conditions.

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