Theory of an Experiment for Measuring the Mobility and Density of Carriers in the Space-Charge Region of a Semiconductor Surface

Abstract

The use of galvanomagnetic experiments to determine the mobility and density of carriers in the spacecharge region of a semiconductor surface is considered. In part I an approximate model is used: it is a single crystal composed of two regions, a surface region of thickness of the order of a Debye length and a bulk region. Expressions for the resultant Hall coefficient are given for three experimental configurations by use of circuit analysis. The sensitivity of each configuration is derived, and by also considering experimental desirability, one is selected for study. It has the magnetic field perpendicular to the surface and the Hall voltages of surface and bulk are in parallel. Changes in Hall voltages of 1 to 50% are expected by using ambients to change the surface potential.