Electron irradiation effects on digermane adsorbed on Si(100) surfaces

The effects of electron-beam irradiation on digermane adsorbed on Si(100) at 120 K have been investigated by temperature programmed desorption (TPD). Digermane adsorbed on clean Si(100) at low exposures exhibits a single H2 TPD peak at 800 K, which originates from the silicon monohydride state on the Si(100) surface. At higher digermane exposures, a new peak appears between 550 and 570 K, and the 800 K peak shifts to lower temperatures. The 570 K peak is believed to originate from surface germanium hydride species. At the highest digermane exposures, a molecular desorption peak appears at approximately 140 K. Electron exposure of Si(100) dosed heavily with digermane causes the molecular TPD peak at 140 K to decrease in intensity and broaden, with a concomitant increase in TPD peak intensity at 570 K, indicating that the electron beam dissociates physisorbed digermane species via deposition of GeHx species onto the Si(100) surface.