Optimization of a SiGe:C HBT in a BiCMOS technology for low power wireless applications

94-GHz fT, 0.4-dB NFmin HBT with Optimized Si Cap and Extrinsic Base Using Blanket SiGeC Epitaxy

“…In this paper, we describe the profile design of the extrinsic base, which includes link base implantation and cobalt silicidation, in accordance with the intrinsic Si cap. There are a lot of previous works on the intrinsic profile optimization of HBT, 3,4,6) however, we could hardly find simultaneous discussions on the intrinsic profile and the extrinsic base design. The optimized profile led to the realization of an HBT with f T of 94 GHz, and NF min values of 0.4 dB at 2 GHz and 0.7 dB at 5 GHz.…”

“…In these applications, a bipolar CMOS (BiCMOS) process that can minimize complexity to achieve low costs and a short turn-around time is required rather than extremely high-frequency characteristics. 3,4) Since these wireless systems operate at frequencies of 2-5 GHz, the required cutoff frequency of HBT is in the range of 50 to 100 GHz.…”

Low-noise amplifiers in wireless communications: state of the art, two new wideband all-active LNAs in SiGe-BiCMOS

“…They entirely maintain the key advantages of silicon processing [41]. In SiGe processes, peak transition frequencies are obtained for lower collector current and noise figures are reduced up to frequencies of 10 GHz [43][44][45]. Besides the improvement in the bipolar transistor's performance, SiGe processes offer very easy integration of CMOS devices to create BiCMOS technologies with improvements in the properties of both the bipolar and the MOS devices.…”

“…The trend continues to this day, although silicon has gradually been supplanted by a new composite: silicon-germanium (SiGe). Thanks to the boost in the performance by this doping, SiGe has become the material of choice for wireless ICs and low-power radio-frequency components [41][42][43][44]. SiGe offers a bridge between low-cost, low-power, low-frequency silicon chips and high-cost, high-power, high-frequency chips made from materials such as Gallium-Arsenide (GaAs) and Indium-Phosphate (InP).…”

Base transit time of graded-base Si/SiGe HBTs considering recombination lifetime and velocity saturation

“…Since the first Si/SiGe heterojunction bipolar transistor (HBT) was reported in 1988 [1], the tremendous progress of Si/SiGe HBTs has been reached to have a maximum oscillation frequency of 285 GHz [2], a cut-off frequency of 350 GHz [3], and circuit applications on wireless [4] and optical communication [5]. The narrowbandgap of SiGe allows heavy doping in the base with a concentration up to 2 • 10 20 cm À3 [6], which significantly reduces the base resistance and hence increases the maximum oscillation frequency, as compared to the conventional Si bipolar junction transistors.…”