Influence of initial amorphous layer deposition temperature on lateral solid-phase epitaxy of silicon

The influence of deposition temperature (T_d) of initial amorphous layer on the lateral solid-phase epitaxy (L-SPE) of silicon was investigated in a wide deposition temperature range between -20°C and 405°C. Nomarski optical microscopy, scanning electron microscopy (SEM), cross-sectional transmission microscopy (TEM) and microprobe reflection high-energy electron diffraction (μ-RHEED) techniques were used. A hitherto unnoticed markedly strong correlation was found between T_d and L-SPE growth where the lowest deposition temperature of T_d = -20°C gave the highest growth rate and best film quality. Detailed SEM and TEM observation of amorphous Si (a-Si) films revealed that there were many vertical pores threading through a-Si films. A new L-SPE growth model explaining T_d-dependent growth rate was proposed in terms of growth delay induced by the vertical pores. Low-temperature deposition of initial amorphous layers was shown to be an effective way of achieving high-quality films in a short time.