Anisotropic Etching of Cobalt Thin Films Using High Density Plasma of Ethylenediamine/Ar Gas Mixture

초록

Dry etching of Co thin films patterned with TiN hard marks was conducted using a high-density plasma of ethylenediamine/Ar gas mixture. The effects of ethylenediamine concentration on the etch characteristics of the Co thin films were examined. In addition, the main etch parameters were investigated in terms of the etch rate, etch selectivity, and the etch profile. Scanning probe microscopy, optical emission spectroscopy, and X-ray photoelectron spectroscopy (XPS) were utilized to elucidate the etch mechanism in ethylenediamine/Ar gas chemistry. XPS analysis confirmed the formation of Co(CN)2 during the etching. Finally, the redeposition-free anisotropic etching of Co thin films patterned with 150 nm lines were achieved using an ethylenediamine/Ar gas mixture.

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