In described examples, a first metal layer is arranged along a periphery of a cavity to be formed between a first substrate and a second substrate. A second metal layer is arranged adjacent to the first metal layer, where the second metal layer includes a cantilever. The cantilever is arranged to deform in response to forces applied from a contacting structure of the second substrate during bonding of the first substrate to the second substrate. The deformed cantilevered is arranged to impede contaminants against contacting an element within the cavity.