Positive Ion and Electron Emission from Cleaved Si and Ge

Cleavage of Si and Ge wafers in a vacuum produces spontaneous positive ion and electron emission with durations ranging from tens of microseconds up to 1.8 ms. The onset of emission is synchronous with the start of cleavage. The electron emission is explained by an Auger process energized by electron capture by a positive ion. The ion emission is about 10⁷ cm ^-2 and is due to a peak in the surface atom vibrational energy distribution, showing that considerable energy is available for forming various surface structures.