Kinetics of Hydrogen Motion via Dislocation Network in Hydrophilically Direct Bonded Silicon Wafers

Abstract

The kinetics of hydrogen penetration through dislocation networks produced by silicon wafer bonding are investigated by means of reverse bias annealing (RBA) procedure. By using the combination of capacitance-voltage (CV) profiling of net-acceptor concentration and deep level transient spectroscopy (DLTS) the total concentration of H introduced in the samples during wet–chemical etching at room temperature was defined. Two processes with the different time constants τ1and τ2was found for the bonded sample. The slow process τ1with an activation energy of (1.25±0.13) eV was analogous to that in the reference sample and corresponded to the dissociation of boron-hydrogen pairs. The fast process τ2was found to exhibit a lower activation energy of (0.87±0.25) eV and was identified as the release of hydrogen bound at screw dislocations by their elastic strains.