The incorporation of thin C- or Zn-doped layers under metal Schottky contacts on n-type GaAs can lead to significant enhancements in the effective barrier height. A single C δ-doped layer (p = 1.3 × 1020 cm–3) within 100 Å of the surface leads to a barrier height of ∼0.9 eV, a significant increase over the value for a control sample (∼0.75 eV). The use of two sequential δ-doped layers can lead either to a further enhancement in barrier height, or a decrease depending on whether these layers are fully depleted at zero applied bias. The temperature dependence of current conduction in barrier-enhanced diodes was measured. Both the ideality factor and breakdown voltage degrade with increasing temperature. Zinc δ-doping in a similar fashion produces barrier heights of 0.81 eV for one spike and 0.95 eV for two spikes.