Silicon has been deposited by a chemical vapor deposition technique using $SiCl_4$ and $H_2$ gas mixture onto Si single crystal substrate.
In this work, the effects of deposition time, total flow rate, deposition temperature, Cl/H ratio, and total pressure on the deposition rate and the crystal morphology of Si deposit have been studied.
From the experiment results, it is found that the deposition reaction of Si is controlled by mass transfer mechanism at temperatures above 1050℃ and by thermally activated surface reaction at temperatures below 1000℃. The apparent activation energy of the thermally activated surface reaction is about 45 Kcal/mole. The morphology of the Si deposit changes from a fine to a coarse structure as the deposition time and temperature increase and as the total pressure decreases. At a temperature of 1050℃, a polycrystalline Si deposit of (220) preferred orientation develops with increasing the deposition time and total pressure, and with decreasing the Cl/H ratio.
At a total pressure of 100 torr, a single crystalline Si deposit is obtained.
