Boron diffusion in Si and SiC during 2.5 MeV proton irradiation at 500-850degrees C

Radiation enhanced diffusion (RED) of B in Si and SIC was investigated usin g similar to 85 nA/cm(2) 2.5 MeV proton bombardment at elevated temperature s. A strong concentration dependence of RED of B in Si is observed. The mob ilization of boron increases with increasing irradiation temperature (with an activation energy of 1.5 eV), so that at 850 degrees C almost 100% of th e boron atoms are mobile. For similar to 1 h anneals at 700 degrees C and 5 00 degrees C the boron atoms in excess of 5 x 10(17) and 1 x 10(17) B/cm(3) stay immobile, respectively. A comparison of our data with that previously reported by other authors shows that the point defect wind originated from the depth of the proton projected range plays a significant role during th e RED measurements in Si. No RED of B was observed in SIC and the migration /trapping parts of the activation energy of B diffusion in SIC are estimate d to be >3.5 eV. (C) 1999 Elsevier Science B.V. All rights reserved.