50 nm Vertical Replacement-Gate (VRG) pMOSFETs

Abstract

We present the first p-channel Vertical Replacement-Gate (VRG) MOSFETs. Like the VRG-nMOSFETs demonstrated last year, these devices show promise as a successor to planar MOSFETs for highly-scaled ULSI. Our pMOSFETs retain the key features of the nMOSFETs and add channel doping by ion implantation and raised source/drain extensions (SDEs). We have significantly improved the core VRG process to provide high-performance devices with gate lengths of 100 nm and below. Since both sides of the device pillar drive in parallel, the drive current per /spl mu/m of coded width can far exceed that of planar MOSFETs. Our 100 nm VRG-pMOSFETs with t/sub ox/=25 /spl Aring/ drive 615 /spl mu/A//spl mu/m at 1.5 V with I/sub OFF/=8 nA//spl mu/m-80% more drive than specified in the 1999 ITRS Roadmap at the same I/sub OFF/. We demonstrate 50 nm VRG-pMOSFETs with t/sub ox/=25 /spl Aring/ that approach the 1.0 V roadmap target of I/sub ON/=350 /spl mu/A//spl mu/m at I/sub OFF/=20 nA//spl mu/m without the need for a hyperthin (<20 /spl Aring/) gate oxide.