The AC electrical characterization of Au/porous silicon/p-Si structures is presented. The low porosity Porous Silicon layers were prepared by electrochemical etching in p-type silicon <100> with two resistivities. The AC electrical measurements capacitance – conductance – frequency were performed from 5Hz to 10MHz, at room temperature in the DC range of ± 2V. We studied two structures; first a conductor type Au/PS/Au and second diode type Au/PS/p-Si/Al.
Using silicon wafers p-Si as starting material and electrochemical anodizing process permit to obtained commonly a nanostructured semiconductor material [1,2]. The material produced is known as Porous silicon (PS) [3,4]. In order to investigate its electrical properties, two main porous silicon structures are formed by a p-Si wafer; the first structure is between two metal electrodes on top, usually aluminum [5,6] or gold [7,8]. Thus, the structure produced it’s a conductor type (metal/PS/metal). The second structure formed it’s a diode type (metal/PS/p-Si/metal), these structures are in type p crystalline silicon [2,9].
Measurement of AC electrical characterization is im-portant for dielectric characterization of materials. This characterization technique permits to separate the dielectric permittivity properties corresponding to the capacitances present in the relaxation region in the porous silicon layers [10,11]. The AC dielectric analysis is interpreted in terms of the admittance or impedance measurement and the equivalent electrical circuits are formed by RC networks in parallel [12,13], connected in series with an inductance [7,14] or capacitance [9,10].
In relation to the electrical properties of PS structures under forward and reverse bias conditions two main trends are proposed: the first one corresponding to the contribu-tion of the bulk and the second one relative to contribution of the junctions. Specifically, some authors proposed an electrical behaviour for PS structures controlled by the bulk conduction mechanism under forward bias conditions and controlled mainly by the junctions under reverse bias conditions [5,15]. On the other hand, some authors argue that the PS structures electrical behavior, under forward and reverse bias conditions, is...