The effect of precleaning treatments on the formation of Ti silicide

In this work, the effect of the wafer precleaning procedure for low resistance titanium silicide film growth was investigated. This involved Ar sputtering treatment, APM cleaning, HPM cleaning and dilute-HF dipping. The low resistance TiSi2 film formation was realized by a wet precleaning to remove oxide from the Si surface. The higher sheet resistance of TiSi2 film treated by Ar dry cleaning was explained by the thinner film thickness and the interface roughness. Knock-on contaminants trapped in an interfacial amorphous Si layer were formed in the remaining native oxide during Ar dry cleaning. Although a small amount of oxygen at the interface had little influence on the silicidation reaction, knocked-on oxygen and nitrogen inhibited the silicidation reaction.