Analysis of reaction gases flow in CVD processes

The relation between the deposition rate of the films and the velocity distribution in the flow field is investigated in detail. The thin SiN films are deposited on Si substrates by the infrared thermal chemical vapor deposition (CVD) at 600 °C, flux ratio (NH3Si2H6) of 50 and 800 and total pressure of 2 and 10 Torr. Velocity, pressure, temperature and vorticity distributions in a flow past a plate are calculated numerically at 600 °C and Reynolds number (Re) of 1, 10, 40 and 100. From the results it is shown that the deposited film thickness distribution agrees fairly well with the vorticity distribution. The fact suggests that vorticity has a potent influence on film deposition.