STEADY-STATE CURRENT THROUGH A MULTILAYER HOMOSTRUCTURE

General analytical formulas are used to describe macroscopic steady-state transport properties in abrupt L-H (n+-n, p+-p) homostructures as a function of the potential barrier-height reduction. These easy-to-use analytical expressions are useful for the computation (in all nondegenerate bias regimes) of the steady-state low-field characteristic I(V) through structures of the n+-n or n+-n-n+ type (symmetrical or asymmetrical) within the framework of the thermionic emission and quasi-equilibrium current. This approach is especially helpful in microstructure simulation. Excellent agreement is found between our theoretical characteristics and previously reported experimental or numerical results. Our own experiments have been carried out on a family of four Si samples differing only in thickness of the inserted lightly doped layer. An original method for experimental thickness measurements of multilayer structures was employed. The I(V) characteristics have been studied in the steady state and in the pulsed regime (quasi-static). The results establish five bias intervals and three conduction current components. It is shown that the electric properties resulting from a relatively thin multilayer homostructure may be much more sensitive to the geometric factor than to the intrinsic properties of the material composing the inserted layer.