Energy spectrum of backscattered electrons excited by a field emission scanning tunneling microscope with a build-up [111]-oriented W tip

A field emission scanning tunneling microscope (STM) combined with an electron energy analyzer was developed to acquire energy spectra of electrons backscattered from a sample surface impinged by a primary electron beam, which is field-emitted from an STM tip of build-up [111]-oriented W. Since the electron beam is field-emitted from the most protruding point of the [111] apex with a low work function and a sharp corner, the electron impinged area can be imaged with the STM by approaching the build-up W tip to the sample. Electron energy loss and Auger electron spectra were obtained for Si(111); an elastic backscattering peak, bulk plasmon loss peaks and a Si LW Anger peak were detected. The origin of anomalous broad inelastic peaks was also discussed. (C) 1999 Elsevier Science B.V. All rights reserved.