Structural and electrical analysis of poly-Ge films fabricated by e-beam evaporation for optoelectronic applications

Kabacelik I., KULAKCI M., TURAN R.

MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING, vol.56, pp.368-372, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 56
  • Publication Date: 2016
  • Doi Number: 10.1016/j.mssp.2016.09.023
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.368-372
  • Keywords: Germanium thin film, Solid phase crystallization, Ge/Si heterojunction, Current-voltage, GERMANIUM THIN-FILMS, LOW-TEMPERATURE GROWTH, CRYSTALLIZATION, GLASS, CELL
  • Anadolu University Affiliated: Yes


We have investigated the relationship between structural and electrical properties of Ge thin films deposited on single crystal silicon (100) substrates by electron beam evaporation at room temperature. Post-thermal annealing was applied to obtain poly-crystalline Ge thin films. The structural effects of the annealing temperature and annealing time on the crystallization of Ge films were analyzed using Raman and X-ray diffraction measurements. Raman and X-ray diffraction spectra revealed a structural evolution from amorphous to crystalline phase with increasing annealing temperature and annealing time. It was found that high quality poly-crystalline Ge films were obtained with crystallization ratio of 90% at an annealing temperarure of 500 degrees C following the crystallization threshold of 450 degrees C. Effects of structural ordering on the electrical properties were investigated through current-voltage characteristics of fabricated heterostructure devices (Ge/p-Si). Smooth cathode-anode interchange in the diode behavior has been clearly observed following the structural ordering as a function of annealing temperature in a systematic way. These outcomes could be exploited for engineering of low-cost Ge based novel electronic and opto-electronic devices.