Sputter epitaxy of heavily doped p+/n+ Ge film on Si(100) by cosputtering with Al/Sb for solar cell application

Abstract

Heavily doped p+ or n+ Ge films were grown on Si substrates by sputter epitaxy. Ge was cosputtered with Al or Sb to add dopant impurities. The maximum carrier densities were 1.0 × 1021 for p-type films and 8.4 × 1019 cm−3 for n-type films. The activation ratio of Sb was 56%. A pn junction diode was fabricated on a Si(100) substrate; it exhibited a good rectifying property with an on/off ratio of 529.