Organic/inorganic interfacial microstructures achieved by fast atom beam bombardment and vacuum ultraviolet irradiation

To integrate electronic devices and structural materials for divers IoT applications, low temperature solid-state organic-inorganic is crucially important. Here we evaluate feasibility of two of low-temperature bonding techniques, Ar fast atom beam (Ar-FAB) bombardment and vacuum ultraviolet (VUV) irradiation, with their effect on surface/interfacial chemical structures of aluminum and polyimide. A series of in-situ XPS analyses indicate that for aluminum the Ar-FAB treatment resulted in atomically-clean aluminum surface within 1 min, although the VUV did not show obvious modification effects. On the other hand, for polyimide the FAB generated benzene-dominant surface structures, although the VUV resulted in much longer chain fragments (i.e. less matrix damage) by only dissolving side chains like ether and carbonyl groups. It turned out that the VUV achieved the aluminum-polyimide bonding with extremely weak adhesion, but the Ar-FAB could not. Evolutions of surface chemical structure induced by Ar-FAB and VUV treatment, as well as bonding mechanisms, are proposed in this report.