SIMULATION OF INFRARED PICOSECOND LASER-INDUCED ELECTRON-EMISSION FROM SEMICONDUCTORS

In this study, we present a self-consistent model for picosecond laser induced electron emission from silicon. Surface electron emission due to a pulsed laser excitation originates from thermionic and photoelec tric effects, both of which depend on the surface electron temperature and incident laser pulse intensity. By numerically solving a set of c oupled transport equations, time dependent surface electron temperatur e as well as lattice temperature was determined. The electron emission rates and electron yields due to photoelectric and thermionic effects have been studied for varying pulse width and pulse intensity. For pi cosecond pulses at 1064 nm, the dominant emission mechanism was found to be photoelectric emission for pulse fluences below the melting thre shold. In addition, a comparison between electron emission due to the picosecond infrared pulse and a picosecond 532 nm pulse was also prese nted. (C) 1998 Elsevier Science B.V.