Title :
Microwave noise of Si/Si/sub 0.6/Ge/sub 0.4/ heterojunction bipolar transistors
Author :
Mohammadi, S. ; Lu, L.-H. ; Ma, Z. ; Katehi, L.P.B. ; Bhattacharya, P.K. ; Ponchak, G.E. ; Croke, E.T.
Author_Institution :
Dept. of Electr. Eng., Michigan Univ., Ann Arbor, MI, USA
Abstract :
The microwave noise of Si/SiGe HBTs was characterized and modeled using a high-frequency T-equivalent noise circuit model. A 6 finger 2/spl times/15 /spl mu/m/sup 2/ HBT showed a minimum noise figure of 2.26 dB with an associated gain of 12.7 dB, measured at 8 GHz under I/sub c/=14 mA and V/sub CE/=3V bias condition. Bias, frequency and HBT geometry dependent noise measurements were also performed. It was found that the 6 finger 2/spl times/15 /spl mu/m/sup 2/ HBT has the best noise performance among the characterized devices. Moreover, it was revealed that minimum noise figure reaches a minimum at a medium collector current. Finally, a simple all physical high-frequency T-equivalent noise model was extracted from the measured S-parameters and noise data and was used for the study of noise dependence on different HBT equivalent circuit parameters.
Keywords :
Ge-Si alloys; electric noise measurement; elemental semiconductors; equivalent circuits; heterojunction bipolar transistors; microwave bipolar transistors; microwave measurement; semiconductor device measurement; semiconductor device models; semiconductor device noise; semiconductor materials; silicon; 12.7 dB; 14 mA; 3 V; 6 finger HBT; 8 GHz; HBT equivalent circuit parameters; HF T-equivalent noise circuit model; S-parameters; Si-Si/sub 0.6/Ge/sub 0.4/; Si/SiGe HBT; geometry dependent noise measurements; heterojunction bipolar transistors; microwave noise; noise performance; Circuit noise; Fingers; Frequency; Gain measurement; Germanium silicon alloys; Heterojunction bipolar transistors; Microwave circuits; Noise figure; Noise measurement; Silicon germanium;
Conference_Titel :
Silicon Monolithic Integrated Circuits in RF Systems, 2000. Digest of Papers. 2000 Topical Meeting on
Conference_Location :
Garmisch, Germany
Print_ISBN :
0-7803-6255-1
DOI :
10.1109/SMIC.2000.844286
