Lateral variation in the Schottky barrier height and ballistic electron transport characteristics of gold/(100)gallium arsenide and gold/platinum silicide/(100)silicon diodes

Ballistic electron emission microscopy (BEEM) was used along with a variety of structural, chemical, and electrical characterization methods to investigate the electronic structure and transport properties of Au/(100)GaAs and Au/PtSi/(100)Si metal/semiconductor (MS) contacts. The first issue addressed was the effect of a native oxide diffusion layer on the stability and homogeneity of Au/(100)GaAs contacts. Next issue was the comparison of the passivation effects of an oxide diffusion barrier to those of a sulfide interlayer on the nanoscopic Schottky barrier height (SBH) distribution of Au/(100)GaAs contacts. The third and most important issue was the spatial inhomogeneity in the SBH formed at Au/PtSi/(100)Si and Au/(100)GaAs diodes. Lateral variations in the SBH were measured on length scales ranging from a few to several hundred nanometers using BEEM. All of the contacts investigated showed SBH spatial inhomogeneity. The most severe SBH variations observed were 0.11V/0.7nm in Au/(100)GaAs contacts and 0.08V/14nm for Au/PtSi/(100)Si contacts. The spatial profile and the statistical distribution of the SBHs thus obtained were compared to broad-area I/V and C/V characteristics of these MS contacts. Based on the lateral maps of the SBH at each interface, the difference between the locally averaged SBH and the globally averaged BEEM SBH was computed. This analysis showed that there is a critical diode area below which the SBH deviates significantly from the average SBH obtained from a larger diode area. This result implies that the uniformity of electrical characteristics of arrays of small devices can be expected to deteriorate significantly when device dimensions decrease below the critical length.;Included in this work are the results of thermal and electrical stability investigation of Co;In addition, the effects of alkali metal deposition on the performance of Mo microtip field emission arrays are described in this Dissertation.