Atomic diffusion bonding (ADB) of wafers at room temperature in air was studied using Ag films. Using an ultra-high vacuum magnetron sputtering system, Ag (20 nm) films with Ti (5 nm) underlayers were deposited. The propagation speed of crystal lattice rearrangement in the bonding process decreased with an increased exposure time of film surfaces to air (t exp). Propagation did not occur at t exp of 500 s. The cohesion of Ag film surfaces by film surface exposure to air and reduction of the Ag film surface energy by Ag oxide or sulfide formation probably cause ADB performance degradation.
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