Control of the formation of Benard cells in a horizontal rectangular duct heated from below

Flows in horizontal chemical vapor deposition (CVD) ducts heated from below play an important role for manufacturing thin semiconductor layers. However, the formation of Benard cells prevents the growth of layers of uniform thickness. The present paper aims at finding conditions for time-mean uniform growth of the layer on the bottom of a rectangular CVD duct of aspect ratio 2 and heated from below. Experimental studies of various side wall temperature distributions were performed to identify conditions appropriate for controlling the Benard cells. It was found that flows in the chaotic state can provide the uniform horizontal temperature distribution preferable for the uniform growth of semiconductor layers.