Solid state devices of all material systems exhibit inherent noise, i.e., random fluctuation in voltage or current, which by having the possibility of drowning the signal set a limit to their ultimate performance. Noise in solid state devices appears in a variety of forms and characteristics, including thermal noise, shot noise, generation-recombination noise, and 1/f noise. Despite the certainty attained over the years, on the origin of the first three types of noise sources, the origin of 1/f noise still remains as a controversial matter. Although numerous fluctuations with 1/f spectral density have been observed in a variety of electronic devices and physical systems, qualitative understanding of the origins of these fluctuations is lacking. Despite the ambiguity on the origins of 1/f noise, understanding the physical origins and mechanisms involved in these random fluctuations is the key to improve the device performance. For the special case of MODFETs, despite their excellent high-frequency noise performance, in many nonlinear applications such as in mixers and oscillators, low frequency noise acts as a limiting factor. Ordinarily, for these devices the observed low frequency noise either consists of a pure1/f noise (with a frequency exponent close to one) or one or several generation-recombination noise bulges, due to traps, submerged in a 1/f noise. In this project, we will engage in designing a measurement setup for automatic measurement and recording of 1/f noise of transistors between 100 mHz and 100 kHz. The major equipment in this setup is a dynamic signal analyzer (i.e. HP3561). Devising a proper interface between the dynamic signal analyzer and a PC through GPIB comprises the programming part of this project. Upon successful implementation of the interface, characterization and analysis of drain and gate low frequency noise of a GaN field effect transistor will be performed.

Students should have sufficient experience in LabView programming. Interest in semiconductors and knowledge at the level of ELEC 311 and ELEC 321 is also necessary. Previous exposure to programming and interfacing of GPIB cards would be very useful.