Experimental Investigation of As Preamorphization Implant on Electrical Property of Ti-Based Silicide Contacts

The impact of As preamorphization implant (PAI) on specific contact resistivity ( ρ
_c
) is investigated for Ti-based Ohmic contacts on n
⁺
-Si in this article. The ρ
_c
value of TiSi
_x
/n
⁺
-Si contacts is greatly improved with low-dose As PAI whereas this improvement is impaired with increased dose of As PAI. The ρ
_c
results from the joint effort of the reduction of effective Schottky barrier height (SBH) to electrons ( φ
_{\text bn,eff}
), retardation of Ti silicidation, and annihilation of end-of-range (EOR) defects. Besides, the interfacial microstructures of TiSi
_x
/n
⁺
-Si affect ρ
_c
, correlated with the post metal anneal (PMA).