Method of measuring the trap level concentration of polycrystalline grain boundaries

摘要

PURPOSE:To make it possible to measure the trap level density of a polycrystal grain boundary by a method wherein an electrostatic capacity per unit area of an insulation film, temperature, and the inclination of gate voltage characteristics to the drain current in a subthreshold area are determined and a calculation is made on the basis of a specific equation regarding these physical quantities. CONSTITUTION:In an insulation gate field effect type transistor with a polycrystal semiconductor having a permittivity of epsilons(F/cm) as a substrate material, an electrostatic capacity Ci(F/cm2) per unit area of an insulation film, temperature T(K), and the inclination S(V/column) of gate voltage characteristics to the drain current of a subthreshold area are specifically determined. A calculation is made using equation I on the basis of physical quantities Ci, T and S and the trap level density (piece/V/cm2) of a grain boundary area is measured. This makes it possible to measure the trap level density of a polycrystal grain boundary area.