Semiconductor device simulation of low-frequency noise under periodic large-signal conditions

Noise is defined as any unintended signal that interferes with circuit operation. Although this includes spurious signals of human origin or the external environment, this investigation is limited to noise that results from microscopic fluctuations within the semi-conductor components of the circuit. While noise is typically seen as an analog circuits problem, it is believed that noise will become of greater concern in digital circuits as devices shrink, power supply voltages are reduced, and the number of carriers conducted by these devices is reduced.; Noise under large-signal conditions is an important consideration in the design of wireless communications circuits. It has an affect on the spectral purity of oscillators and the noise figure of mixers and power amplifiers. The ability to simulate the noise of semi-conductor devices makes it possible to predict their performance in these types of circuits. It is then possible to have a better picture of the worst-case performance of these circuits so that overdesign or costly redesigns are not necessary.; This dissertation presents the implementation and simulation of noise under periodic large-signal conditions in a partial-differential equation (PDE) based semiconductor device simulator. The harmonic balance (HB) technique is used to find the periodic steady state of a semiconductor device. Using the impedance field method (IFM) and cyclostationary noise sources, it is possible to simulate the self- and cross-spectral densities between sidebands of a periodic large-signal stimulus.; The first 2-D semiconductor device simulations of diffusion and trap-assisted generation-recombination (GR) noise under periodic large-signal conditions are presented. Examples are provided that show known results for shot noise in junctions and for low-frequency noise in resistors. Additional results show the upconversion of low-frequency GR noise as microscopically stationary noise sources in resistors and as microscopically cyclostationary noise sources in diode junctions and bipolar junction transistors.; It is also shown how the noise correlation matrix (NCM) for circuit simulation can be found through device simulation. It is also demonstrated that low-frequency noise due to trap-assisted GR fluctuations can be modeled using the modulated stationary noise model for the purposes of circuit simulation.