Metals Contacts on Cleaved Silicon Surfaces

Abstract

Glossary of Symbols Potential drop across space charge region at equilibrium. Difference between Fermi level and bottom of conduction band deep Difference between Fermi level and top of valence band at the con-Applied reverse bias. Negative of intercept on V , axis of plot of 1/C2 versus TI , . Energy gap in semiconductor, 1.100 ev for silicon. Potential drop across separation between metal and semiconductor at equilibrium. Potential drop across separation between metal and semiconductor with applied bias V , . Work function of metal. Electronegativity of semiconductor. Charge in space charge region in semiconductor. Charge in surface states on semiconductor (positive for donor and Magnitude of electronic charge (positive quantity). Dielectric constant of semiconductor, 11.8 for silicon. Width of separation between metal and semiconductor. Donor density in semiconductor. Electron density in body of semiconductor. Dielectric constant of separation between metal and semiconductor. Electron density in body of intrinsic semiconductor, 3.9 X 10 T exp (-0.605 ev/kT) for silicon. Differential capacitance ( d Q / d V ) .

Electrical transport characteristics of Sn/p-Si schottky contacts revealed from I–V–T and C–V–T measurements

“…Most of the early work focused on the use of C-V characteristics to obtain this information [22]. For example, Crowell and Roberts [23] determined the energy distribution of surface state in Au-Si diodes from C-V characteristics reported by Archer and Atalla [24], but they did not consider whether the distribution was consistent with the I-V characteristics of the devices. Recently, Levine [25] has suggested that the anomalous I-V characteristics of the SBDs are consistent with a barrier model in which there is an exponential distribution of surface states and in which the barrier height is controlled by this energy distribution of surface states and the externally applied voltage.…”

Properties of silicon-metal contacts versus metal work-function, silicon impurity concentration and bias voltage

“…They are relative to the temperature T=300 K and to the bias voltage V-0. The experimental values of Vint and of the silicon Fermi level Es (evaluated upward from the bottom of the conduction band (figure 1)) are deduced from the measurements made by Archer and Atalla (1963) on contacts constructed by depositing the metal on cleaved-in-vacuum samples of silicon in DUCUO.…”

“…By returning to the quantum and electrical 'complete' model, one notes that this allows one to explain the experimental results of Archer and Atalla (1963) and of Crowell et al (1965), according to which an intervening oxygen layer between metal (with the exception of Sb) and silicon reduces the value of Villt in the case of the low-work-function metals (Ca, Mg, Al, Ag and Cu), whereas it does not act on such a quantity in the case of high-work-function metals (Au, Ni, Pd and Pt). In fact, the interfacial oxygen layer, with its great energy gap, reduces the quantum-mechanical tunnelling of the metal free electrons into the semiconductor, and as a consequence it reduces the dipole contribution V d O which is a large part of Vb and of Vint for the low-work-function metal.…”

The physics of Schottky barriers

“…Following the pioneering work of Archer and Atalla (1963), the semiconductor we know most about as far as Schottky barriers are concerned is silicon. An extensive study of metal-silicon barriers by Turner and Rhoderick (1968) (iii) in the case of etched surfaces the barrier depends on the choice of metal, but not to the extent predicted by the Schottky theory, and (iv) in the case of surfaces cleaved in ultra-high vacuum, the barrier is almost independent of the metal (see figure 4).…”