Professor Balandin's Nano-Device Laboratory (NDL) research group is engaged in physics-based device modeling and computer simulation of electronic devices. Using both in-house built simulation tools and commercial software NDL members handle state-of-the-art conventional devices as well as alternative technology device prototypes: from vertical MOSFETs to quantum logic gates. Apart from research benefits the use and working knowledge of the best available commercial software packages is intended to help NDL alumni in job search. The modeling work in NDL is closely corellated with the group's experimental activities described HERE.

NDL has a history of research cooperation with some of the manufactures of the device simulation software. Our partners include researchers of the CFD Research Corporation, one of the leading device simulation tool developers in US. The joint projects with CFD Research Corporation involved acoustic phonon spectrum simulation in semiconductor nanostructures and were funded by the US AFOSR (see the project details). CFD-ACE+ package, the most advanced computational fluid dynamics and multi-physics software tool offered by CFD Research Corporation, is available for students and postdoctoral researchers affiliated with NDL. This software package enables coupled simulations of fluid, thermal, chemical, biological, electrical and mechanical phenomena. It is used by the semiconductor, biotech and aerospace industries.

Figure 1. Holes current distribution after beginning of source-drain breakdown.

Another software package available at NDL is ISE TCAD developed by the Integrated Systems Engineering. Specifically, NDL members use ISE TCAD to simulate electrical, thermal, and optical characteristics of semiconductor devices. It is one of the leading device simulators, which handles 1D, 2D, and 3D geometries, mixed-mode circuit simulation with compact models, and numerical devices. It contains a comprehensive set of physical models that can be applied to all relevant types of semiconductor devices and operation conditions. DESSIS is also used to evaluate and understand how a device works, optimize devices, and extract SPICE models and statistical data early in the development cycle. Figure 1 shows electrical current distribution in GaAs MESFET simulated using DESSIS.

FEMLAB, another simulation tool available at NDL, is an interactive environment for modeling and simulating scientific and engineering problems based on partial differential equations (PDEs)-equations that are the fundamental basis for the laws of science. FEMLAB's multi-physics feature allows one to simultaneously model any combination of phenomena. FEMLAB's graphical user interface includes functions for CAD modeling, physics or equation definitions, automatic mesh generation, equation solving, visualization, and post-processing. FEMLAB is used by NDL group members for simulation heat flow in GaN/AlGaN heterostructure field-effect transistors (HFETs) in the project supported by ONR. Figure 2 shows temperature distribution in GaN/AlGaN HFET structure obtained with the help of FEMLAB.

Figure 2. Temperature rise profile in the doped channel GaN/AlGaN HFET on SiC substrate.
Results are after Filippov and Balandin, Proceed of NanoTech, Vol.3, pp. 333-336, 2003

In addition to the device simulation tools described above, NOMAD group and EE Department offer access to and courses on the use of Cadence CAD tools for CMOS integrated circuit design, layout and verification. More information on Cadence CAD tools in UCR can be found HERE.

Figure 3. Research Associate Dr. Valentin Turin is modeling performance
degradation of GaN-based transistors due to self-heating.
Nano-Device Laboratory, 2003.

More information on the projects currently under way in the Nano-Device Laboratory (NDL) can be found HERE. To join NDL as a graduate student or postdoctoral research visit the web-page HERE. To learn more about course offering in the field of Materials, Devices and Circuits visit the web-page HERE.