Features of current flow in structures based on Au/Ti/n-InAlAs Schottky barriers

Resumo

Current–voltage (I–V) characteristics of Au/Ti/n-InAlAs/InP Shottky barriers have been studied in a temperature range of 100–380 K. It is established that, as the temperature increases from 100 to 200 K, the ideality factor drops from 1.58 to 1.1, while the barrier height grows from 0.55 to 0.69 eV. With a subsequent temperature increase from 200 to 380 K, both the ideality factor and barrier height vary, but only weakly. This behavior agrees well with the model of lateral inhomogeneity of the barrier height (Tung model), which is confirmed by the linear dependence of the barrier height on the ideality factor at temperatures within 100–200 K. Calculations according to this model yielded the value of 0.88 eV for the homogeneous-junction barrier height, 10^–4 cm^2/3 V^1/3 for the mean-square deviation of the Gaussian distribution of barrier heights, 3.7 × 10^–11 cm² for the effective area of regions with reduced barrier heights, and 10.7 A cm^–2 K^–2 for the Richardson constant.