Evidence of hole-optical-phonon interaction in degenerate silicon in tunneling measurements

Tunneling from a metal into degenerate p-type silicon exhibits peaks in d2idV2 at biases eV=±ω0, where ω0 is the k=0 optical-phonon energy of the semiconductor. It is suggested that these peaks reflect modifications in the bulk semiconductor states at energies ω0 above and below the Fermi energy arising from hole-optical-phonon interaction. An additional peak near the optical-phonon frequency, but well resolved from it, is identified with vibrations of the boron acceptor impurity.