Selective plating of nickel ceramic composite films for MEMS applications

Abstract

A simple, selective and CMOS-compatible deposition method for nickel ceramic composite film has been demonstrated. Using electroless plating technique, two types of nickel ceramic composite thin films, nickel-cordierite and nickel-iron (II, III) oxide, have been successfully deposited and characterized on silicon substrates. The incorporation of an appropriate amount of cordierite particles into a nickel matrix is shown to significantly reduce the thermal expansion mismatch between nickel and silicon, yet maintain the Young's modulus, Berkovich hardness and electrical resistivity at approximately 167 GPa, 7.6 GPa and 9.4 mW-cm, respectively, which correspond closely to electroless nickel. On the other hand, the addition of iron (II, III) oxide instead of cordierite can also increase the coercivity of electroless nickel up to 170 Oe, thereby significantly enhances its ferromagnetic property.