Publications (2)0 Total impact
Article: Impact of strain and channel orientation on the low-frequency noise performance of Si n- and pMOSFETs[show abstract] [hide abstract]
ABSTRACT: Mobility and low-frequency (LF) noise were studied in tensile strained Si n- and pMOSFETs fabricated on relaxed SiGe virtual substrates. Both the impact of the channel orientation (〈1 1 0〉 or 〈1 0 0〉 on (1 0 0) Si) and the tensile strain were carefully investigated. Two types of virtual substrates were used; a thin relaxed SiGe layer (20% Ge) and a thick one (27% Ge). The strained Si nMOSFETs fabricated on the thin substrate showed similar LF noise level as in the reference devices, whereas the thick substrate caused severely increased LF noise in the nMOSFETs. The latter was linked to the higher Ge concentration and explained by possible misfit dislocations and increased defect densities, likely resulting from strain relaxation caused by ion implantation damage. On the other hand, considerably lower LF noise was achieved in the pMOSFETs on the thick SiGe. The channel orientation was not found to have a significant influence on the LF noise performance in any of the studied devices.Solid-State Electronics. 05/2007; 51(5):771.
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ABSTRACT: Strained Si is recognised as a necessary technology booster for the nanoelectronics regime. This work shows that high levels of stress attainable from globally strained Si/SiGe platforms can benefit gate leakage and reliability in addition to MOSFET channel mobility. Device self-heating due to the low thermal conductivity of SiGe is shown to be the dominating factor behind compromised performance gains in short channel strained Si/SiGe MOSFETs. Novel thin virtual substrates aimed at reducing self-heating effects are investigated. In addition to reducing self-heating effects, the thin virtual substrates provide further improvements to gate oxide integrity, reliability and lifetime compared with conventional thick virtual substrates. This is attributed to the lower surface roughness of the thin virtual substrates which arises due to the reduced interactions of strain-relieving misfit dislocations during thin virtual substrate growth. Good agreement between experimental data and physical models is demonstrated, enabling gate leakage mechanisms to be identified. The advantages and challenges of using globally strained Si/SiGe to advance MOS technology are discussed.Microelectronic Engineering.