Toward Conformal Damage-Free Doping With Abrupt Ultrashallow Junction: Formation of Si Monolayers and Laser Anneal as a Novel Doping Technique for InGaAs nMOSFETs

New doping techniques are needed for the formation of abrupt, ultrashallow junctions with high doping concentration in the source/drain or source/drain extension regions of metal-oxide-semiconductor field-effect transistors (MOSFETs) at advanced technology nodes. In addition, 3-D device structures, such as fin field-effect transistors, require a good doping conformality. In this paper, the formation of monolayers of silicon on InGaAs by disilane or silane treatment of the InGaAs surface is studied as a conformal dopant source that does not introduce ion implant damage into the InGaAs, and laser anneal is used to drive in and activate the dopants to form an ultrashallow and very abrupt n⁺⁺-junction. This novel doping technique is first demonstrated in planar InGaAs MOSFETs.