Electroless Deposited Nickel Hard Mask for High Density Plasma Etching Applications

Abstract

Ni electroless films were used as a material for hard mask during high-density ICP plasma etching. The results have shown that under the plasma exposure strong hardening of the mask occurs and the rate of Ni film removal falls at least an order of magnitude as compared with its initial value. Therefore, very high selectivities for Si etching over Ni are obtained, allowing for very deep etching required for some MEMS applications.