Luminescence and Electrical Characterization of Ion Implanted Si:Tl.
Final technical rept. Jan 80-Jan 82,
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
Pagination or Media Count:
Ion implanted SiTl was characterized by luminescence, Hall-effect, Rutherford Backscattering RBS, and Secondary Ion Mass Spectrometry SIMS. This is the first reported luminescence study of an implanted dopant in silicon. The same sharp line defects were produced by the Tl heavy ion implants as identified in previous light ion studies. The defects produced by the ion implantation were removed and the Tl activated by a two-step anneal procedure. A high quality annealed implant layer was produced from which the four excited states of the Tl bound exciton no-phonon could be resolved. An unidentified bound exciton peak related to the Tl acceptor was observed for the first time in both ion implanted and bulk grown SiTl. Temperature dependent Hall-effect measurements were made on the implant layers which indicate that Hall-effect measurements made only at room temperature are not valid in general for silicon implant layers. The Hall data and luminescence data both indicate that the concentration of activated Tl increases with increasing second anneal temperature. The Hall-mobility varied as T-2.4 for implanted SiTl in the temperature range 135-165K. The ionization energy was determined to be 229 meV by Hall-effect measurements in the compensated temperature region.
- Solid State Physics