Growth of 3C-SiC via a hot-wall CVD reactor

• Main Author: Harvey, Suzie
• Format: Others
• Published: Scholar Commons 2006
• Subjects: Silicon carbide; Heteroepitaxy; SOI; Crystal defects; Chemical vapor deposition; American Studies; Arts and Humanities
• Online Access: http://scholarcommons.usf.edu/etd/2552; http://scholarcommons.usf.edu/cgi/viewcontent.cgi?article=3551&context=etd

The heteroepitaxial growth of cubic silicon carbide (3C-SiC) on silicon (Si) substrates at high growth rates, via a horizontal hot-wall chemical vapor deposition (CVD) reactor, has been achieved. The final growth process was developed in three stages; an initial "baseline" development stage, an optimization stage, and a large area growth stage. In all cases the growth was conducted using a two step, carbonization plus growth, process. During carbonization, the surface of the Si is converted to 3C-SiC, which helps to minimize the stress in the growing crystal. Propane (C3H8) and silane (SiH4), diluted in hydrogen (H2), were used as the carbon and silicon source, respectively. A deposition rate of approximately 10 um/h was established during the baseline process. Once the baseline process proved to be repeatable, optimization of the process began. Through variations in temperature, pressure, and the Si/C ratio, thick 3C-SiC films (up to 22 um thick) and high deposition rates (up to 30 um/h) were obtained. The optimized process was then applied to growth on 50 mm diameter Si(100) wafers. The grown 3C-SiC films were analyzed using a variety of characterization techniques. The thickness of the films was assessed through Fourier Transform infrared (FTIR) spectroscopy, and confirmed by cross-section scanning electron microscopy (SEM). The SEM cross-sections were also used to investigate the 3C-SiC/Si interface. The surface morphology of the films was inspected via Nomarsky interference optical microscopy, atomic force microscopy (AFM), and SEM. The crystalline quality of the films was determined through X-ray diffraction (XRD) and low-temperature photoluminescence (LTPL) analysis. A mercury probe was used to make non-contact CV/IV measurements and determine the film doping.