Geometry and structure of sputter-induced cones on nickel-seeded silicon

Scanning and transmission electron microscopic studies of Ar+ sputter-induced cones on nickel-seeded silicon suggest that Ni atoms are highly deposited on the upper cone slope to form delta-winged cones at temperatures lower than 400 degrees Celsius. At temperatures below 200 degrees Celsius, Ni formed the seed layers, while nickel silicide is observed above 200 degrees Celsius, which is silicidized to NiSi2 above 300 degrees Celsius. NiSi2 formation is triggered by Ar+ bombardment. Around 500 degrees Celsius, an eutectic reaction between Ni and Si is triggered by impacting Ar+ ions.