Nickel-Silicide Contact Technology With Dual Near-Band-Edge Barrier Heights and Integration in CMOS FinFETs With Single Mask

Abstract

This letter reports the demonstration of a nickelsilicide contact technology that achieves dual near-band-edge barrier heights (i.e., a low electron barrier height Φ n B for n-FETs and a low hole barrier height Φ p B for p-FETs) using just one additional masking and two ion-implant steps. Independent and effective tuning of contact resistance R C is achieved in both p-and n-FinFETs. The compensation effect of aluminum and sulfur implants is studied for the first time and exploited for process simplification. A novel cost-effective integration scheme is shown to give significant I DSAT enhancement for p-and n-FinFETs.Index Terms-Aluminum (Al) implant, contact resistance, double-species implant, FinFETs, nickel silicide (NiSi), Schottky barrier height, sulfur (S) implant.

Impact of a Germanium and Carbon Preamorphization Implant on the Electrical Characteristics of NiSi/Si Contacts With a Presilicide Sulfur Implant

“…3 shows the depth profiles of S and C in the metal/semiconductor structure. It has been reported that segregated S at the NiSi/Si interface is the key factor to tune Φ n B [9]- [14]. S is found to segregate at the NiSi/Si interface for both samples.…”

“…Furthermore, the addition of carbon (C) after PAI also enhances the thermal stability of NiSi and removes the end-ofrange (EOR) defects in amorphized Si [7], [8]. Manuscript On the other hand, it has been reported that introduction of sulfur (S) at the NiSi/n + Si interface can reduce the effective SBH or Φ n B to ∼0.1 eV [9]- [14]. S could act as a dopant to increase the thermionic field emission and tunneling current [15].…”

Review paper: Advanced source and drain technologies for low power CMOS at 22/20 nm node and below

“…[77] Al and S implantation before NiSi formation to achieve near-bandedge barrier height for PMOS and NMOS, respectively, has been reported for FinFETs. [78] In other studies, PMOS received both Al and S implants, with Al doping level lower than S, while NMOS received only an Al implant, using one additional mask, which allows simpler CMOS process. A NiAl alloy was also demonstrated on NMOS FinFETs, forming Ni 2 AlSi.…”