Dopant behaviour and damage annealing in silicon implanted with 1 kev arsenic

The level of activation in ultra-shallow As doped Si as a function of the
anneal condition has been investigated with spreading resistance profiling
(SRP), four point probe (FPP) and Van der Pauw (VDP) methods. Double
alignment medium energy ion scattering (MEIS) and low energy secondary ion
mass spectrometry (SIMS) have been used to assess the damage annealing and
dopant behaviour in the near surface regions. An inactive dopant solid
solution was formed in Si following re-growth of the amorphous layer. When
annealing in an oxidising ambient, although a high fraction of the
implanted dose remains trapped in the oxide layer, a higher level of
electrical activation is observed than compared to the non-oxidising
anneal. Evidence of dopant out diffusion is observed during high
temperature annealing in a non-oxidising gas ambient. The processes that
occur during the anneal in the near surface regions of the sample
have been discussed and related to the level of dopant activation achieved.