Wayne M. Greene

Boron diffusion and penetration in ultrathin oxide with poly-Si gate

Boron penetration through thin gate oxide down to 17 /spl Aring/ is investigated in this work. Boron penetration is characterized by the amount of flat band shift in a MOS capacitor. The effective diffusion coefficient of boron in these thin oxides is found to be higher than in thicker oxides. The introduction of a moderate dose of fluorine (1/spl times/10/sup 15/ cm/sup -2/) during gate doping enhances boron penetration in these thin oxides. Compared to as-deposited polycrystalline silicon (poly-Si), crystallized amorphous silicon (/spl alpha/-Si) films display slower boron diffusion in the gate and reduce enhancement of boron penetration due to fluorine. However, crystallized /spl alpha/-Si gate also reduces the amount of dopant activation and leads to extra gate depletion. The tradeoff between dopant activation and boron penetration is discussed.

Design considerations of high-/spl kappa/ gate dielectrics for sub-0.1-/spl mu/m MOSFET's

The potential impact of high-/spl kappa/ gate dielectrics on device short-channel performance is studied over a wide range of dielectric permittivities. It is shown that the short-channel performance degradation caused by the fringing fields from the gate to the source/drain regions, is mainly determined by the gate thickness-to-length aspect ratio. In addition, the gate stack configuration also plays an important role in the determination of the device short-channel performance degradation.

Effects of channel and source/drain implants on partially-depleted SOI MOSFETs

The effects of channel and source/drain implants on device characteristics of partially-depleted SOI (PD-SOI) MOSFETs were studied. Devices with a retrograde channel profile show less short-channel effect (SCE), less edge and back channel leakage currents, and more severe reverse short channel effect (RSCE) compared to devices with a uniform channel profile. When the source/drain junction is formed by a single implant instead of extensions, the I/sub D/-V/sub DS/ kink effect is more pronounced. Source/drain junction formed by a phosphorus implant was demonstrated for the first time for deep submicron PD-SOI MOSFETs.