Abstract
As the silicon industry continues to push the limits of device dimensions, tools such as Raman spectroscopy are ideal to
analyze and characterize the doped silicon channels. The effect of inter-valence band transitions on the zone center optical
phonon in heavily p-type doped silicon is studied by Raman spectroscopy for a wide range of excitationwavelengths extending
from the red (632.8 nm) into the ultra-violet (325 nm). The asymmetry in the one-phonon Raman lineshape is attributed to a
Fano interference involving the overlap of a continuum of electronic excitations with a discrete phonon state. We identify a
transition above and below the one-dimensional critical point (E1
= 3.4 eV) in the electronic excitation spectrum of silicon. The
relationship between the anisotropic silicon band structure and the penetration depth is discussed in the context of possible
device applications.
