Work function measurements for surface analysis

Abstract

A measurement system includes: an excitation system; a detector; and a control unit. The excitation system includes excitation sources generating excitations of different types comprising: a high energy electromagnetic radiation source; at least one electric power supply providing a bias voltage to a sample; and at least one electron beam source generating relatively low energy e-radiation in the form of an electron beam. The excitation system includes first and second sequentially performed measurement modes, for respectively, exciting the sample by the high energy radiation to induce a first-mode secondary electron emission spectral response, and supplying initial bias voltage to the sample and exciting the sample with the e-radiation followed by a gradual variation of the bias voltage from said initial bias voltage to induce a second-mode electric current variations in the sample. The detector detects said first-mode secondary electron emission spectral response and generates first-mode measured data, and monitors the electric current through the sample and generates second-mode measured data indicative of sample current readout.