Direct Silicidation of Co on Si by Rapid Thermal Annealing

Abstract

Rapid thermal annealing is used to form cobalt silicide directly on unimplanted as well as B, As, and P implanted wafers. The films are characterized by sheet resistance, X-ray diffraction, SEM, SIMS, and contact resistance measurements. The direct silicidation of cobalt on Si by rapid thermal annealing yields smooth, low resistivity films with minimal dopant redistribution.

Growth Kinetics of Palladium Silicides Formed by Rapid Thermal Annealing

“…With this approach and by assuming a diffusion-controlled growth process deduced from Table I for our case, Eq. [1], [2] can be written as f2…”

Characterization of a Self‐Aligned Cobalt Silicide Process

“…Selectivity was achieved by etching for 15s in 3 HCI:I H202 to remove cobalt from the oxide. More recently (16), 70 nm evaporated Co was rapfd thermal annealed at 900~ for 10s in N2 and followed by the same selective etch to give a 23 ~s 230 nm CoSi2 film with no evidence of lateral diffusion or residues left on oxide regions. We have also found that a single rapid thermal anneal suffices to produce smooth CoSi2 films of minimal sheet resistance with no bridging over or encroachment under the oxide (Fig.…”

“…The disilicide films are stable on silicon substrates at temperatures <950~ (26). Cobalt silicide formation during RTA in a nitrogen ambient has been studied over a limited temperature range (16,27). Between 500 ~ and 1000~ the reaction proceeds to CoSi2 via CoSi formation (16).…”

“…Cobalt silicide formation during RTA in a nitrogen ambient has been studied over a limited temperature range (16,27). Between 500 ~ and 1000~ the reaction proceeds to CoSi2 via CoSi formation (16). Other workers examining 540~176 found only CoO at 540~ CoSi2 above 750~ and a CoO surface layer with a CoSi2 interfacial layer at intermediate temperatures (27).…”