Analytical study of impact ionization and subthreshold current in submicron n-MOSFET

The effect of impact ionization in subthreshold operation of an n-MOSFET is studied. Analysis shows that the effect of impact ionization cannot be neglected in the subthreshold region of operation of the submicron MOSFET. This effect is enhanced at larger drain voltages. Gate bias and oxide thickness controls the effect of impact ionization. The effect of impact ionization is through the gate and drain bias dependence of the maximum electric field. The subthreshold current increases when the gate oxide is thinned. This is because of the increase in impact ionization due to the increase in electric field.

[2]  K. Tatsuuma,et al.  A drain avalanche hot carrier lifetime model for n- and p-channel MOSFETs , 2004, IEEE Transactions on Device and Materials Reliability.

[3]  New experimental findings on hot carrier effects in deep submicrometer surface channel PMOS , 1996 .

[4]  New experimental findings on hot carrier effects in sub-0.1 μm MOSFET's , 1995, IEEE Electron Device Letters.

[5]  A. Duncan,et al.  Full-band Monte Carlo investigation of hot carrier trends in the scaling of metal-oxide-semiconductor field-effect transistors , 1998 .

[6]  A. Toriumi,et al.  Hot-carrier effects in 0.1 mu m gate length CMOS devices , 1992, 1992 International Technical Digest on Electron Devices Meeting.

[7]  Yuan Taur,et al.  Fundamentals of Modern VLSI Devices , 1998 .

[8]  J. Woo,et al.  Enhanced subthreshold leakage current due to impact ionization in deep sub-100nm N-channel double-gate MOSFETs , 2001, 2001 IEEE International SOI Conference. Proceedings (Cat. No.01CH37207).

[9]  Tor A. Fjeldly,et al.  Unified substrate current model for MOSFETs , 1997 .

[10]  Chenming Hu,et al.  A thermal activation view of low voltage impact ionization in MOSFETs , 2002, IEEE Electron Device Letters.

[11]  M. Shur,et al.  Threshold voltage modeling and the subthreshold regime of operation of short-channel MOSFETs , 1993 .

[12]  I. Eisele,et al.  A detailed experimental investigation of impact ionization in n-channel metal–oxide–semiconductor field-effect-transistors at very low drain voltages , 2003 .

[14]  P ? ? ? ? ? ? ? % ? ? ? ? , 1991 .

[16]  T. Morimoto,et al.  Hot-carrier reliability of ultra-thin gate oxide CMOS , 2000 .