Selective Cu-growth on fine-structure by using Cu-iodide precursor

Abstract

Abstract Selective Cu-deposition by chemical vapor deposition using Cu-iodide (I) as the precursor is applied on 0.5 μm- and 1.0 μm-pitch Cu-line/SiO2-space at 370 ⁰C. Confocal laser microscope suggests the Cu is selectively deposited on the Cu-line, not on the space. The average Cu-height provided by the cross-sectional profile across the 1.0 μm-pitch L/S, which is linearly increased with total CuI-supply, evaluates the dissociation efficiency of CuI is about 23%. Surface SEM and EDS clearly shows the selective deposition of Cu, but surface roughness on the deposited Cu is increased with the Cu-height. The feature of surface roughness is discussed on the coalescent Cu-line at the deposition temperature and the rate-limiting step in the CVD. The selective Cu-deposition is also performed on the 0.5 μm-pitch L/S, in which the deposition rate is similar but the surface is rougher than on the 1.0 μm-width line.