EXPLANATION OF THE LINEAR CORRELATION BETWEEN BARRIER HEIGHTS AND IDEALITY FACTORS OF REAL METAL-SEMICONDUCTOR CONTACTS BY LATERALLY NONUNIFORM SCHOTTKY BARRIERS

A new and simple-to-use method to obtain homogeneous Schottky barrier heights from effective barrier heights and ideality factors that are d etermined from current-voltage (I-V) characteristics of metal-semicond uctor contacts is presented. This approach is justified by a theory of metal-semiconductor interfaces with laterally inhomogeneous distribut ions of barrier heights. Effective barrier heights and ideality factor s were determined from I-V characteristics of Si and GaN Schottky cont acts and a linear reduction of the effective barrier heights with incr easing ideality factors was always observed. These findings are explai ned by numerical simulations of inhomogeneous Schottky contacts which are based on theoretical results by Tung [Phys. Rev. B 45, 13509 (1992 )], The homogeneous barrier heights of metal-semiconductor contacts ar e obtained by a linear extrapolation of the effective barrier heights to n(if) congruent to 1.01, the value of the ideality factor character istic for image-force lowering of Schottky barriers only. (C) 1997 Ame rican Vacuum Society.