Abstract

SARIKAVAK, B et al. MBE-growth and characterization of In_xGa_1-xAs/GaAs (x=0.15) superlattice. Rev. mex. fis. [online]. 2008, vol.54, n.6, pp.416-421. ISSN 0035-001X.

A qualified In_0.15Ga_0.85As/GaAs superlattice was grown on an n-type GaAs(100) substrate by molecular beam epitaxy(MBE). Analysis of this structure was first carried out by X-Ray diffraction (XRD) and this structure's the interface thicknesses, roughness and x concentration determined at nanoscale. Secondly, the electrical characteristics of this sample such as the current-voltage-temperature (I-V-T), capacitance-voltage-temperature (C-V-T) and conductance-voltage temperature (G-V-T) were studied over a wide temperature range. The energy distribution of interface states was determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height. Experimental results show that the forward and reverse I-V characteristics are similar to Schottky-junction behavior. The ideality factor n, series resistance R_s, barrier height Φ_B and density of interface states N_ss were found to be strong functions of temperature. According to thermionic emission (TE) theory, the zero-bias barrier height (_Bo) calculated from forward bias I-V characteristics was found to increases with increasing temperature. In addition, the value of R_s as a function of both voltage and temperature was obtained from C-V and G-V characteristics. The temperature dependent of I-V, C-V and G-V characteristics confirmed that the distribution the R_s and N_ss are important parameters that influence the electrical characteristics of these devices.

Keywords : MBE; X-Ray diffraction; series resistance; interface states; temperature dependent.

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