Surface dopant concentration measurement using the Surface Charge Profiler(SCP) method: characterization of hydrogen and metallic contamination in silicon

Boron deactivation by pairing with contaminants and boron compensation are studied in silicon wafers from various IC manufacturing processes using the Surface Charge Profiler (SCP) method. Dissociation energies of pairs forme d due to noble metals contamination in HF chemistries are the same independ ently of the noble metal and correspond to the one of B-H pairs. This sugge sts that metals are not directly responsible for the doping change but enha nce hydrogen contamination into the silicon during HF cleaning. Hydrogenati on during SC1 clean (ammonium hydroxide-peroxide mixture), RCA clean (RCA = SC1 + SC2 where SC2 is hydrochloric acid-peroxide mixture), and plasma etc hing is responsible for boron deactivation through B-H formation. Copper co ntamination introduced into Si during thermal oxidation compensates initial boron doping by formation of stable complexes. (C) 1999 Elsevier Science S .A. All rights reserved.