Copper filling of deep sub-μm through-holes by high-vacuum planar magnetron sputtering using argon gas with added oxygen

Changes in filling characteristics when adding oxygen to sputtering gas (1 at.%N2-Ar) were investigated using high-vacuum planar magnetron sputtering equipment having little residual gas effects. It was found that copper filling accelerates for oxygen partial pressure in sputtering gas of PO2=5×10−5to1×10−4Pa and a substrate temperature of 300-320 °C. Under these conditions, 70% copper filling in fine holes of diameter ϕ = 100 nm (AR = 4.5) was obtained.