Comparison of thermal reactions of phosphine on Ge(100) and Si(100) by high-resolution core-level photoemission

The thermal decomposition processes of phosphine (PH;) on a Ge(I 0 0)-2 x I surface at temperatures between 325 and 790 K were investigated and compar ed with those on Si(I 0 0)-2 x 1. High-resolution synchrotron radiation cor e-level photoemission spectra indicates that. at room temperature phosphine molecularly adsorbs on the Ge(I 0 0)-2 x I surface, however on the Si(1 0 0)-2 x I it partially dissociates into PH2 and H. Successive annealing of t he PH3-saturated Si(1 0 0) and Ge(I 0 0) surfaces at higher temperatures si milarly converts PH3 into PH2 and PH2 to P. P atoms form stable P-P and/or P-Si dimers on Si(I 0 0) above 720 K. but exhibit complex bonding configura tions on Ge(1 0 0). (C) 2001 Elsevier Science B.V. All rights reserved.