A method is disclosed for making a wafer-level package for a plurality of
MEMS devices. The method involves preparing a MEMS wafer and a lid wafer,
each having respective bonding structures. The lid and MEMS wafers are
then bonded together through the bonding structures. The wafers are
substantially free of alkali metals and/or chlorine. IN a preferred
embodiment, each wafer has a seed layer, a structural underlayer and an
anti-oxidation layer. A solder layer, normally formed on the lid wafer,
bonds the two wafers together.