J. Phys. IV France 08 (1998) Pr3-3-Pr3-8
Invited PaperI. Alawneh1, E. Simoen1, S. Biesemans1, K. De Meyer1, 2 and C. Claeys1, 2
Comparison of the freeze-out effect in ln and B doped n-MOSFETs in the range 4.2 - 300 K
1 IMEC, Kapeldreef 75, 3001 Leuven, Belgium
2 KU Leuven, ESAT-INSYS, Kard. Mercierlaan 94, 3001 Leuven, Belgium
In a first part, the impact of low temperature operation on the classical short channel effects will be discussed critically. Particular attention will be given to the reduction of the threshold voltage VT with effective device length in the temperature range 4.2 K to 300 K and to the short-channel behaviour of the subthreshold swing 1/S. In a second part, the impact of dopant freeze-out on the static operation of deep submicron n-MOSFETs will be studied. A comparison is made between standard 0.25 µm B doped and exploratory 0.1 µm In doped transistors. Although the experimental threshold voltage behaviour of deep submicron MOSFETs at cryogenic temperatures can be qualitatively described by the standard equations, a significant difference is noted between the measured and the calculated VT, which is most pronounced in the liquid helium temperature range. Possible additional factors which should be taken into account in a refined modeling will be pointed out, with particular emphasis on the contribution of the interface state charge.
© EDP Sciences 1998