ULTRASHALLOW P(-N JUNCTIONS IN SILICON(100) - ELECTRON-BEAM DIAGNOSTICS OF THE SURFACE ZONE())

Ultrashallow p(+)-n junctions formed in silicon (100) under nonequilib rium impurity diffusion conditions an analyzed by electron-beam diagno stics of the surface zone using a probe of low-to medium-energy electr ons. The energy dependence of the radiation conductivity is investigat ed, along with its distribution over the area of the p(+)-n junction. This procedure can be used to determine the depth distribution (in the crystal) of the probability of separation of electron-hole pairs by t he field of the p-n junction; the experimental results show that this distribution differs according to whether the kick-out mechanism or th e dissociative vacancy mechanism of impurity diffusion is predominant as the basis of formation of the ultrashallow p(+)-n junctions. Also r eported hen for the first time are the results of investigations of th e distribution of secondary point centers formed near the boundary of the ultrashallow diffusion profile, which exert a major influence on t he transport of nonequilibrium carriers. The data obtained in the stud y demonstrate the possibility of improving the efficiency of photodete ctors, alpha-particle detectors, and solar batteries constructed on th e basis of ultrashallow p-n junctions. (C) 1998 American Institute of Physics. [S1063-7826(98)00201-4].