DocumentCode :
1512777
Title :
Input capacitance scaling related to short-channel noise phenomena in MOSFET´s
Author :
Birbas, Alexios N. ; Triantis, Dimitris P. ; Plevridis, Sofokles E. ; Tsakas, Evangelos F.
Author_Institution :
Dept. of Electr. & Comput. Eng., Patras Univ., Greece
Volume :
46
Issue :
6
fYear :
1999
fDate :
6/1/1999 12:00:00 AM
Firstpage :
1253
Lastpage :
1257
Abstract :
In optical (charge) amplifier design, it is common practice, to size the input MOSFET so that the amplifier´s input capacitance is approximately equal to the value of the photodiode capacitance. When plotted versus capacitance, the input equivalent noise current reaches its minimum value, for a given drain bias current, in a curve widely known and characterized as a shallow one. For high bit rate photocurrent amplifiers, which employ short-channel MOSFET´s as the input device, the observed sensitivity degradation is due to the increased input referred noise attributed to the MOSFET´s short-channel operation. It is shown here that for short-channel MOSFET´s the electron warming in the channel, the voltage fluctuations due to the gate polysilicon resistance, and the induced thermal noise at the gate, lead to a considerably lower value for the optimum input capacitance. In this case, the noise power versus the capacitance curve becomes steeper and the minimum is more prominent
Keywords :
MOSFET; capacitance; equivalent circuits; fluctuations; semiconductor device models; semiconductor device noise; thermal noise; channel electron warming; drain bias current; gate polysilicon resistance; high bit rate photocurrent amplifiers; induced thermal noise; input capacitance scaling; input equivalent noise current; input referred noise; noise power/capacitance curve; sensitivity degradation; short-channel MOSFETs; short-channel noise phenomena; voltage fluctuations; Capacitance; MOSFET circuits; Optical amplifiers; Optical design; Optical noise; Optical sensors; Photodiodes; Semiconductor optical amplifiers; Stimulated emission; Thermal resistance;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/16.766894
Filename :
766894
Link To Document :
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