Solid-phase epitaxial crystallization of a B-delta-doped superlattice in Si

Abstract

Time-resolved reflectivity (TRR) and secondary-ion mass-spectrometry (SIMS) are used to study the solid-phase-epitaxial-crystallization (SPEC) of amorphous Si layers containing a B delta-doped superlattice. The superlattice consists of three narrow B profiles (10 nm FWHM) separated by approximately 170 nm, each with a peak concentration of 1.3×10 20 B.cm -3. The SPEC velocity is shown to increase to a rate approximately three times that of intrinsic Si as the crystalline-amorphous interface passes through each B profile, the velocity enhancement closely following the B distribution. Diffusive broadening of the B profiles is also observed during SPEC. This is used to estimate the diffusivity of B in amorphous Si, which was found to be 2.6±0.5×10 -16 cm 2/s at 600 °C. Show more