Dopant diffusion during rapid thermal oxidation

Rapid thermal processing (RTP) is of increasing interest in silicon mainstr eam technology providing reduced thermal budget. In this paper the dopant d iffusion behaviour during rapid thermal oxidation (RTO) is investigated, in particular the oxidation enhanced diffusion (OED). For diffusion monitorin g, samples were fabricated by means of molecular beam epitaxy (MBE) to crea te sharp doping profiles with nanometer resolution. After various RTO treat ments (dry and wet oxide) resulting in an ellipsometric measured oxide thic kness of 5 nm, the distribution of dopants was analysed by secondary ion ma ss spectroscopy (SIMS) and compared with standard thermal processes. Metal- oxide-semiconductor structures (MOS-structures) were fabricated for electri cal characterisation, It turns out that for a low thermal budget and minimi sed OED only wet RTO is feasible.(C) 2000 Published by Elsevier Science Ltd . All rights reserved.