Correlating drain-current with strain-induced mobility in nanoscale strained CMOSFETs

Abstract

The correlation between channel mobility gain (Deltamu), linear drain-current gain (DeltaI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dlin</sub> ), and saturation drain-current gain (DeltaIdsat) of nanoscale strained CMOSFETs are reported. From the plots of DeltaI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dlin</sub> versus DeltaI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dsat</sub> and ballistic efficiency (Bsat,PSS), the ratio of source/drain parasitic resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SD,PSS</sub> ) to channel resistance (R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CH,PSS</sub> ) of strained CMOSFETs can be extracted. By plotting Deltamu versus DeltaI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dlin</sub> , the efficiency of Deltamu translated to DeltaI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dlin</sub> is higher for strained pMOSFETs than strained nMOSFETs due to smaller RSD,PSS-to-RCH,PSS ratio of strained pMOSFETs. It suggests that to exploit strain benefits fully, the RSD,PSS reduction for strained nMOSFETs is vital, while for strained pMOSFETs the DeltaI <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dlin </sub> -to-Deltamu sensitivity is maintained until R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SD,PSS</sub> becomes comparable to/or higher than R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CH,PSS</sub>