Charge generation and collection in p-n junctions excited with pulsed infrared lasers

The author examines optical absorption processes for applications of infrared lasers to the simulation of single-particle effects in silicon and GaAs, which require that the laser is focused to a small area on the device surface. The resulting charge generation is compared with charge generation from heavy ions. Charge funneling is reduced in silicon structures because of the lower charge density unless the LET (linear energy transfer) is above a threshold value. In both materials, the effective LET of a laser is inherently nonlinear because of nonlinear absorption at high intensities. These factors limit quantitative comparisons between lasers and heavy ions, and are increasingly important as devices are scaled to smaller dimensions.>