Electron-induced processes on silicon and germanium precursors on silicon(100)

Electron-induced processes on disilane $\rm Si\sb2H\sb6,$ trimethylsilane $\rm (CH\sb3)\sb3SiH$ (TMS), and digermane $\rm Ge\sb2H\sb6$ adsorbed onto Si(100) at low temperatures (110-125 K) were investigated. The techniques used in this investigation were Auger electron spectroscopy (AES), x-ray photoelectron spectroscopy (XPS), electron stimulated desorption (ESD), high resolution electron energy loss spectroscopy (HREELS), temperature programmed desorption (TPD), low energy electron diffraction (LEED), and secondary ion mass spectroscopy (SIMS). The design and construction of a system with capabilities for the techniques mentioned, being an integral part of this project, are discussed. Two total removal cross-sections of hydrogen from Si(100) were obtained by analyzing electron stimulated desorption (ESD) data. By comparing the ESD data to the TPD traces obtained from disilane/Si(100), the cross-sections obtained were assigned to two adsorption states of hydrogen on Si(100). The dissociation of TMS and deposition of carbon on Si(100) via electron irradiation of TMS/Si(100) were confirmed by TPD and HREELS. In addition, the HREELS data unambiguously confirmed that the silicon dihydride state does not form on TMS-covered Si(100) surfaces. Similarly, TPD and HREELS data indicate that electron irradiation of digermane overlayers on Si(100) dissociates the parent molecules and deposits germanium on the surface. XPS data shows that the deposition of germanium onto Si(100) is at least twice as effective by electron irradiation than by thermal means