Sequential Regeneration of Self-Assembled Monolayers for Highly Selective Atomic Layer Deposition

Next generation 3D electronic devices will require novel processing methods. Area selective atomic layer deposition (ALD) of robust films has the opportunity to play an important role in significantly reducing complexities associated with current top-down fabrication processes of patterned structures. An all-vapor process is demonstrated for depositing and regenerating thiol self-assembled monolayers (SAMs) on copper between ALD cycles. It is shown that by redosing SAM precursors, the SAM quality can be restored after it begins to degrade. It is also shown that this approach is effective in improving the blocking properties of the SAMs against ZnO ALD. This process allows selective deposition of dielectric films on dielectric regions of patterned Cu/SiO2 substrates more than three times thicker than approaches that do not regenerate the SAM. In addition, this all-vapor strategy provides the ability to integrate the selective deposition process into the ALD reactor, reduces artifacts associated with depositing the SAMs on porous or 3D structures, and decreases the required deposition time for the passivation layer, opening up the possibility for new applications in next generation electronic devices.