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 microse conds up to 1.8 ms. The onset of emission is synchronous with the star t of cleavage. The electron emission is explained by an Auger process energized by electron capture by a positive ion. The ion emission is a bout 10(7) cm(-2) and is due to a peak in the surface atom vibrational energy distribution, showing that considerable energy is available fo r forming various surface structures.