Scaling of characteristic frequencies in RF CMOS

• Published in: IEEE transactions on electron devices Vol. 51; no. 12; pp. 2102 - 2108
• Main Authors: Boots, H.M.J., Doornbos, G., Heringa, A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-12-2004; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; CMOS integrated circuits; Cut-off frequency; Design. Technologies. Operation analysis. Testing; Electronics; Exact sciences and technology; Integrated circuits; maximum oscillation frequency; RF CMOS; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; TCAD; Cut off frequency; Cut-off frequency; maximum oscillation frequency; Frequency characteristic; Circuit design; Complementary MOS technology; TCAD; Oscillation frequency; Contact resistance; Computer aided design; Gain; RF CMOS
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2004.838449

Device simulation of the 180-, 90-, and 65-nm CMOS generations shows that in NMOSTs, the cut-off frequency f/sub T/ and the maximum oscillation frequency f/sub max/ are roughly inversely proportional to the gate length. The voltage-gain bandwidth f/sub A/ depends only weakly on the gate length. At 40-nm gate length, f/sub T/ values of 300 GHz are predicted. For small values of the drain and source contact resistance (<10/sup -8/ /spl Omega//spl middot/cm/sup 2/), f/sub T/ can only be improved by a further reduction of the gate length. The f/sub max/ values (for zero gate resistance higher than f/sub T/) degrade strongly with increasing gate resistance. Simple approximate formulas for the dependence of f/sub T/ and f/sub A/ on the contact resistances are presented.