Evaluation of back-side secondary ion mass spectrometry for boron diffusion in silicon and silicon-on-insulator substrates

Abstract

We present a study on the redistribution of boron in (100) crystalline silicon and silicon-on-insulator (SOI) substrates after rapid thermal processing (RTP). The use of SOI back-side secondary ion mass spectrometry (SIMS) technique in obtaining an accurate diffusion profile is also investigated. Our results show that the boron diffusion profiles (using conventional frontside SIMS) do not deviate in any of the two types of substrates after RTP with a soak time of 30sec, indicating that the insulating effect of SOI substrate does not enhance the diffusion of boron. Since the profile obtained by the back-side SIMS technique is always shallower than that of front-side SIMS, it is deduced that the back-side SIMS technique gives a better representation of the real profile.