Evaluation of the Quantum Well Tunneling Diode and the Quantum Electron-Wave Interference Diode as High Speed Devices.

Continuous scaling down of critical device dimensions to improve speed and increase density is approaching the fundamental size limitation of the electron wavelength. New physical concepts have to be examined and harnessed in future electronic devices. The quantum transport properties of electron devices such as the quantum well tunneling diode (QWTD) and the quantum electron-wave interference diode (QEWID) offer an alternative direction for the semiconductor industry. The QWTD has demonstrated useful high speed characteristics as an oscillator, a detector and a switch. This thesis evaluates the QWTD and the QEWID as future high speed devices using a numerical method based on the time -dependent Schrodinger equation. The ac response results for the QWTD are in line with other numerical results and experimental results. Previously neglected effects such as space charge and scattering will be included in the ac calculation. Effects of extrinsic circuit elements on the QWTD dc characteristics are also examined both experimentally and theoretically. In addition, the effect of extrinsic and intrinsic circuit parameters on the QWTD ac performance are investigated. The results are used to compare the QWTD and QEWID performance and ascertain their potential for high speed applications.