1 p.m. - 2 p.m. Location: ECSS 3.503
BIO: Sam (Hisashi) Shichijo is a Research Professor in the Electrical and Computer Engineering department and the Texas Analog Center of Excellence (TxACE) at the University of Texas at Dallas (UTD). He received his M.S. and Ph.D. degrees from the University of Illinois at Urbana-Champaign and his B.S degree from the University of Tokyo. Before joining the UTD faculty in 2010, Dr. Shichijo spent 28 years with Texas Instruments in various technical and managerial positions. One of his last projects at TI as a TI Fellow was the TCAD simulations of CMOS and high voltage transistors and analog passive components. His current interest includes high frequency noise and random telegraph signal in CMOS and bipolar devices and high voltage semiconductor devices including GaN HEMT transistors. He is a Fellow of IEEE.
ABSTRACT: Traditionally high frequency noise characterization of semiconductor devices is made by the use of a tuner in order to sweep the input impedance and construct noise contours for the purpose of extracting noise parameters. However, this approach is rather specialized, expensive and time-consuming. A theoretical framework has existed for many years for fully characterizing the noise parameters without using a tuner. This method relies on the transformation of Y-parameter representation with known noise sources into a chain matrix representation where noise parameters can be explicitly calculated. This is possible because the noise mechanisms in bipolar devices at high frequency are known to be shot noise and thermal noise. The only unknown quantity is the correlation between the emitter and base current shot noise which is characterized by a noise transit time in the transport noise model and impacts the overall noise figure of a device considerably. We will discuss several experimental and theoretical approaches that the noise transit time can be extracted. One method we have adopted is to calculate the noise transit time from the HICUM compact model equations. It will be shown that this method gives the noise transit time in good agreement with the value experimentally extracted from the tuner-based measurement. This enables the full characterization of noise parameters in SiGe HBTs without actually taking the noise data with a tuner.
Donna Kuchinski, 972-883-5556
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