| dc.description.abstract | With the evolution of technology, electronic product-related applications have spread to various industries. Semiconductor component materials utilize conductivity changes to process information. The tri-five semiconductor is an element with a wide energy gap and high thermal conductivity, and is one of the focuses of semiconductor materials. In the thin film process, Metal Organic Chemical Vapor Deposition (MOCVD) can grow various semiconductor metal compounds with good uniformity with the replacement of the precursor. In this study, TMAl and NH3 were used as precursors for AlN film growth. In order to meet the electrical requirements of the device, the resistance value of the aluminum nitride film must be adjusted. If the carbon concentration in the film is too high, the resistance value increases. It is vital that controlling the carbon content in the film.
When growing AlN films, many literatures have explored the use of experimental parameters to control the generation of nanoparticles in the parasitic reactions. In the past literature, there have been few studies on the carbon content of grown AlN films. In this study, a numerical model including Trimethyl Aluminum (TMAl), Ammonia (NH3), carrier gas Hydrogen (H2)reaction and carbon gas phase reaction was established to investigate the effects of various process parameters such as temperature, pressure, reaction precursor flow rate and carrier gas flow rate on the carbon concentration of the film.
The results show that when the temperature is raised, the rate of thermal cracking reaction is accelerated, and more MMAl and methane are generated. Thus, the carbon concentration of the film increases. When the pressure of the cavity is increased, the methane desorption reaction will be accelerated, causing the main adsorbed species to change from methane to ethene , causing the film carbon concentration to rise. When the Hydrogen flow rate, Hydrogen can inhibit the NH3 dissociation, and reduce the concentration of active N precursor in the gas phase reaction, causing more N vacancies in the film to make carbon preferentially occupy. When the NH3 flow rate is increased, the methyl group forms a non-adsorbed methane , the main carbon adsorption species inside the cavity is reduced, so the film carbon concentration decreases. When the TMAl flow rate is increased, more reaction gases can thermally crack the methyl molecules, making the carbon-containing adsorption species higher The concentration of the film thus increases the carbon concentration of the film.
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