UNIQUE HYDRIDE CHEMISTRY ON SILICON-PH3 INTERACTION WITH SI(100)-(2X1)

The dissociative adsorption of phosphine (PH 3) on Si(100)-(2X1) and its high temperature thermal behavior have been studied by high-resolution electron energy loss spectroscopy (HREELS), Auger electron spectroscopy, and by temperature programmed desorption (TPD). Phosphine adsorbs dissociatively onto Si(100)-(2Xl) at 100 K as PH 2 and H species, as revealed by vibrational bands at 1050 cm-1[£SC (PH 2)] and 2100 cm' 1 [r lt;Si-H)]. The PH 2 (a) undergoes thermal decomposition to adsorbed P and H near 650 K, as determined by HREELS. TPD measurements reveal two PH 3 desorption processes at 485 and 635 K. The 635 K desorption is shown to result from PH 2 +H recombination, while the mechanism for the 485 K desorption cannot be definitely identified. Additionally, two H 2 desorption states were observed at 685 and 770 K. © 1994, American Vacuum Society. All rights reserved.