Metallization Systems on Cvd-Diamond Substrates for Application in Multichip Modules

Abstract

AbstractBecause of its high thermal conductivity, free-standing CVD-diamond is an extremely attractive material for application as the substrate in multichip modules (MCMs). However, this material does present some technological challenges, one being the development of reliable metallization systems. In this work, adherent metallization systems, such as Au/Ti, Au/Ti-W, Au/Ni-Cr, Au/Cr and Cu/Cr have been produced at low temperatures. Thin adhesion/seed metal layers were deposited using sputtering and evaporation techniques. Gold and copper metallization of several microns thickness was accomplished by electroplating over the thin metal layer. Post-deposition annealing of both the adhesion/seed layer and plated metallization systems were performed at temperatures up to 500°C in an effort to enhance adhesion and determine the impact of subsequent high temperature operations on reliability issues such as intermetallic diffusion, delamination, and the impact of surface microcavities. Extremely adherent Au/Cr and Cu/Cr metallization systems appropriate for use in MCM technology were developed.