Elimination of silicon gas phase nucleation using tetrafluorosilane (SiF4) precursor for high quality thick silicon carbide (SiC) homoepitaxy



Tetrafluorosilane (SiF4) gas precursor is utilized to eliminate Si gas phase nucleation and Si parasitic deposition during silicon carbide (SiC) epitaxial growth, otherwise unachievable in similar growth conditions using conventional silane (SiH4) and dichlorosilane (SiCl2H2/DCS) precursors. Higher Si[BOND]F bond strength (565 kJ mol−1) in SiF4 prevents early gas decomposition and Si cluster formation, essential for high temperature SiC chemical vapor deposition (CVD), and yet enables growth of high quality epitaxy in an improved particulate suppressed growth condition. High quality, thick 4H-SiC epilayers >100 µm have been demonstrated using SiF4 with excellent surface morphology, polytype uniformity, crystallinity and low defect density.

original image

Significant (80%) suppression of parasitic deposition (left) using SiF4 reduces particulate generation during growth, and improves the epilayer quality (right).