PEEM imaging of dopant contrast in Si(001)

We report on a quantitative investigation of doping-induced contrast in pho toelectron emission microscopy images of Si devices. The calibration sample s were fabricated using standard photolithography and focused ion beam writ ing, and consisted of p-type (B) stripes of different nominal dopant concen trations (10(18)-10(20) cm(-3)) and line separations, written on n-type (N- d = 10(14) cm(-3)) Si(001) substrates. Using a near-threshold light source, we find that the signal intensity increases monotonically with B concentra tion over the measured range of doping. The measured intensity ratios are i n good agreement with a calculation based on photoemission from the valence band. (C) 2000 Elsevier Science B.V. All rights reserved.