Anil K. Chinthakindi

SiGe HBTs with cut-off frequency of 350 GHz

This work reports on SiGe HBTs with f/sub T/ of 350 GHz. This is the highest reported f/sub T/ for any Si-based transistor as well as any bipolar transistor. Associated f/sub max/ is 170 GHz, and BV/sub CEO/ and BV/sub CBO/ are measured to be 1.4 V and 5.0 V, respectively. Also achieved was the simultaneous optimization of f/sub T/ and f/sub max/ resulting in 270 GHz and 260 GHz, with BV/sub CEO/ and BV/sub CBO/ of 1.6 V and 5.5 V, respectively. The dependence of device performance on bias condition and device dimension has been investigated. Considerations regarding the extraction of such high f/sub T/ and f/sub max/ values are also discussed.

SiGe HBT technology with f/sub max//f/sub T/=350/300 GHz and gate delay below 3.3 ps

This work reports on SiGe HBT technology with f/sub max/ and f/sub T/ of 350 GHz and 300 GHz, respectively, and a gate delay below 3.3 ps. This is the highest reported speed for any Si-based transistor in terms of combined performance of f/sub max/ and f/sub T/ both of which exhibit 300 GHz and above. Associated BV/sub CEO/ and BV/sub CBO/ are measured to be 1.7 V and 5.6 V, respectively. The dependence of device performance on bias condition and device dimension has been investigated. Considerations regarding the extraction of such high f/sub max/ and f/sub T/ values are also discussed.

Differentially-shielded monolithic inductors

Differential shielding reduces substrate losses and improves the Q-factor of a monolithic inductor on silicon by up to 35% without process modification or a patterned ground shield. Peak Qs of 32 for 4 /spl mu/m thick aluminum and 28 for 2.3 /spl mu/m thick copper metals are demonstrated on 10 /spl Omega/-cm substrates for a 7.7 nH test inductor. The differential shield fulfills all existing metal density requirements, and a compact circuit model is presented that agrees within 8% of measurement.

RFCMOS technology from 0.25/spl mu/m to 65nm: the state of the art

The effort to design RF circuits in CMOS is motivated by low cost and significant capacity for on-chip integration. We discuss some of the challenges of implementing RF designs in CMOS, focusing on those introduced by the changing properties of FETs as technology nodes scale and devices shrink. We present methods and tools, using which, designers can ease these challenges and reduce the risk of implementing RF circuits in CMOS.

SiGe HBTs for millimeter-wave applications with simultaneously optimized f/sub T/ and f/sub max/ of 300 GHz

Millimeter-wave applications are gaining growing interest in recent times. To meet the challenges for such applications, SiGe HBTs, with simultaneously optimized f/sub T/ and f/sub max/ of >300 GHz, are developed. To the authors knowledge, this is the first report of f/sub T/ and f/sub max/ both exceeding 300 GHz for any Si-based transistor. BV/sub CEO/ and BV/sub CBO/ are 1.6 V and 5.5 V, respectively, with peak current gain of 660. Noise measurement shows F/sub min/ of 0.45 dB and 1.4 dB at 10 GHz and 25 GHz with associate gain of 14 dB and 8 dB, respectively. The results indicate SiGe HBTs are highly suitable for the rapidly expanding millimeter-wave applications.