Ballistic-electron emission microscopy and internal photoemission in AurSi-structures — a comparison

Ballistic-electron emission microscopy BEEM.and internal photoemission IPE.measurements have been performed on Aurn-Si structures with 100. and 111. substrate orientation. Schottky-barrier energies EBs0.825"0.010 eV for Aurn-Si 111. and EBs0.790"0.015 eV for Aurn-Si 100. have been obtained by using both methods. The barrier energies are found to be independent of the Au-film thickness d. Furthermore, the internal yield Y for BEEM and IPE were determined and quantitatively compared to one another. For both methods, Y increases considerably as d decreases. For very thin Au-layers, the internal yield of both methods nearly converges. For thicker layers, their shapes differ slightly with the IPE yield data showing the higher values. The observations indicate that the different starting conditions of BEEM and IPE are of minor influence on the internal yield. q2000 Elsevier Science B.V. All rights reserved.