Characteristics of BF3 plasma-doped gate/source/drain for 0.18-mu m pMOSFETs

A BF3 plasma doping (PLAD) process has been utilized in shallow source/drai n (S/D) extension and source/drain/gate doping for high-performance 0.18-mu m pMOSFETs. Low-resistance shallow junctions were obtained using a BF3 PLAD system with a high-performance low-energy boron doping technology. The dri ve current and transconductance of pMOSFETs with plasma-doped S/D extension s are remarkably improved compared to those of BF2+ ion-implanted devices, due to the low resistance of the S/D extension at the equivalent short-chan nel-effect characteristics. The fluorine ions in the BF3 plasma-doped silic on are significantly less than in the BF2+ implanted one. In the case of su rface channel pMOSFETs with a BF3 plasma-doped gate, the boron penetration and depletion in the gate poly were reduced because of the reduced fluorine incorporation into the gate poly compared to those of a conventional BF2 i on-implanted gate. The improved characteristics of BF3 plasma-doped gate en hance the drive current and gate oxide quality of pMOSFETs compared to conv entional BF2+-implanted devices. No plasma damage was identified, and cobal t salicide formation is also very compatible with the plasma-doped p(+)/n j unction. (C) 2001 Published by Elsevier Science B.V. All rights reserved.