Chemical vapor deposition wafer boat

DETAILED DESCRIPTION The chemical vapor deposition wafer boats of this invention are means for supporting a plurality of wafers in an evenly spaced, upright orientation perpendicular to the axis of the boat.
The boat comprises a cylinder having closed ends and having mutually engaging upper and lower hemicylinders, the upper hemicylinder having diffusion zones with gas flow passageways therein in the ends and in zones within from 0 to 75 degrees from a horizontal plane through the cylinder axis and from 0 to 15 degrees from a vertical plane through the cylinder axis.
The remainder of the hemicylinder wall constitutes baffle areas without gas flow passageways.
The ends and sidewall of the lower hemicylinder constitute gas diffusion zones.
The gas flow passageways comprising from 0.
5 to 80 percent of the surface area of the respective gas diffusion zones.