Selective functionalization of silicon surface controlled by metastable helium atom beam for patterning chemisorbed monolayer molecular assemblies

Metastable neutral helium atoms are highly chemical sensitive to surface dangling bonds. As the basis of a new lithographic technique, a method for fabrication of self‐assembled monolayers (SAMs) and mixed SAMs by the irradiation‐promoted exchange reaction has been recently developed. Metastable helium atoms irradiation is shown to modify organosilane SAM films and Si–H and Si–OH covering surfaces, which render the surface amendable to further SAM modification. The exposure regions can undergo a second chemisorption reaction to produce an assembly of octadecyltrichlorosilane SAMs. Metastable helium atom beam patterned films can be used as templates for selective buildup of fluorophores, amino group, and biological cells to obtain further surface functionalization.