Effective barrier heights of mixed phase contacts: Size effects

Abstract

Computer simulations of mixed phase Schottky contacts have been performed to gain insight into the effects oflateral dimensions upon device behavior. As expected, lateral dimensions comparable to the Debye length of the semiconductor result in strong modification of the device characteristics that would result from independent, parallel diodes. We suggest that such effects can playa role in most experimentally obtained contacts. Current models of Schottky barrier formation typically invoke kinetics-limited chemical interactions at the metal-semiconductor interface; such effects are unlikely to be laterally uniform over macroscopic dimensions, and may well provide strong sensitivity to seemingly minor variations in preparation techniques used by different groups. We demonstrate that mixed phase contacts, with size effects, can affect ideality factors, and can also cause disagreement between C-Vand 1-V barrier heights.

Metal–organic interfaces at the nanoscale

“…This "physics" is "generic" to wide band-gap semiconductors, which organics are. Several studies [25][26][27] have demonstrated that small interfacial ''patches'' with reduced local Schottky-barrier height (SBH) of size comparable to or less than the semiconductor Debye length, cause a ''potential pinch-off'', i.e. current is funneled through the low barrier patch.…”

Correlation Between Barrier Heights and Ideality Factors of Ni/n-Ge (100) Schottky Barrier Diodes

“…This may be due to the sensitivity of the Schottky interfaces to preparation procedures and to different techniques of measuring the BH [17]. In recent years, studies of SBH inhomogeneities have been carried out [16,19,[23][24][25][26][27][28][29][30]. Freeouf et al [23] reported on the influence of a small patch with a low BH within the contact area on the ideality factor and the essence of the contact area size in this effect.…”

“…In recent years, studies of SBH inhomogeneities have been carried out [16,19,[23][24][25][26][27][28][29][30]. Freeouf et al [23] reported on the influence of a small patch with a low BH within the contact area on the ideality factor and the essence of the contact area size in this effect. Song et al [16] reported that the BH difference over the contact area was attributed to variations in the interfacial layer thickness and/or chemical composition and to the non-uniformity of the interfacial charges.…”

The physics and chemistry of the Schottky barrier height

“…[145][146][147] That this is a necessary consequence of SBH inhomogeneity has long been realized. [148][149][150] For certain types of work, only the result of one type of SBH measurement is important, e.g., I-V measurement for ohmic contact development. For other types of applications and investigations, the entire profile of the SBH distribution at an MS interface is of interest, in which case the experimental techniques and conditions that are needed to provide the desired, complete information should be carefully thought out.…”