Date of Award
Doctor of Philosophy (PhD)
Micro and Nanoscale Systems
Arden L. Moore
The field of microelectronics plays an important role in many areas of engineering and science, being ubiquitous in aerospace, industrial manufacturing, biotechnology, and many other fields. Today, many micro- and nanoscale electronic devices are integrated into one package. e capacity to simulate new devices accurately is critical to the engineering design process, as device engineers use simulations to predict performance characteristics and identify potential issues before fabrication. A problem of particular interest is the simulation of devices which exhibit exotic behaviors due to non-equilibrium thermodynamics and thermal effects such as self-heating. Frequently, it is desirable to predict the level of heat generation, the maximum temperature and its location, and the impact of these thermal effects on the current-voltage (IV) characteristic of a device. is problem is furthermore complicated by nanoscale device dimensions. As the ratio of surface area to volume increases, boundary effects tend to dominate the transfer of energy through a device. Effects such as quantum confinement begin to play a role for nanoscale devices as geometric feature sizes approach the wavelength of the particles involved. Classical approaches to charge transport and heat transfer simulation such as the drift-diffusion approach and Fourier’s law, respectively, do not provide accurate results at these length scales. Instead, the transport processes are governed by the semi-classical Boltzmann transport equation (BTE) with quantum corrections derived from the Schrodinger equation ̈ (SE). In this work, a technique is presented for coupling a 3D phonon Monte Carlo (MC) simulation to an electron multi-subband Monte Carlo (MSBMC) simulation. Both carrier species are first examined separately. An electron MC simulation of bulk silicon, a silicon n-i-n diode, and an intrinsic-channel fin-field effect transistor (FinFET) structure are also presented. A 3D phonon MC algorithm is demonstrated in bulk silicon, a silicon thin film, and a silicon nanoconstriction. These tests verify the correctness of the MC framework. Finally, a novel carrier scattering system which directly accounts for the interaction be- tween the two particle populations inside a nanoscale device is shown. e tool developed supports quantum size effects and is shown to be capable of modeling the exchange of energy between thermal and electronic particle systems in a silicon FinFET.
Spence, Tyler J., "" (2019). Dissertation. 826.