Area-selective atomic layer deposition (AS-ALD) has drawn significant attention in the past decade because of the potential applications in bottom-up processing, which enables fabricating nanostructures at the atomic level without multiple patterning and lithographic processing that could easily cause alignment issues. Although AS-ALD has been demonstrated using various self-assembled monolayers (SAMs), it is still challenging to develop wet SAM deposition for AS-ALD that is suitable for industrial and semiconductor processes. In this work, we demonstrate highly effective AS-ALD of Al2O3 on Co/SiO2 patterned wafers using fluorinated thiol in both solution and vapor phase. Compared with conventional SAMs using alky-thiols, the fluorinated-thiol SAMs demonstrate greater blocking ability against ALD precursors owing to excellent hydrophobicity. Furthermore, much shorter deposition times can be achieved in vaporizable fluorinated thiol molecules, improving processing throughput and productivity. Most importantly, the SAM regeneration and redosing processes can further enhance the selectivity of AS-ALD, opening a promising avenue to realize the bottom-up approach in practical semiconductor applications.
Keywords: amphiphobic; area-selective ALD; fluoroalkyl-thiols; metal-dielectric patterns; self-assembled monolayers.