New self-aligned fabrication methods are developed and studied for making thin film structures for semiconductor devices. The methods are controlled by surface chemistry which is selective to the underlying materials that are exposed on the surface of the device being made. As a result, thin film is formed in a self-aligned manner only on top of certain material(s) while others are left uncovered. The great benefit of the self-alignment is that the number of photolithography steps in semiconductor fabrication can be decreased. This will decrease also alignment errors between subsequent parts of thin film structures that are unavoidably associated with the lithography. Both area-selective atomic layer deposition and area-selective etching of polymers will be studied where the latter is a radically novel approach to the self-aligned thin film fabrication. For both methods new processes will be developed and reaction mechanisms leading to the selectivity will be studied in detail.

2021

2026