Susceptor for heating semiconductor substrates

In a susceptor of the type comprising a hollow polyhedron having a plurality of walls, each wall adapted to support on its outer planar surface one or more substrates in nearly vertical orientation, each of said substrates being generally polygonal or circular of a given diameter and having a center, the improvement comprising:

• each wall being subdivided into a plurality of surface regions in vertical alignment, said regions being bounded by horizontal edges that are spaced slightly larger than one of said substrates, each surface region having a center, each region being arranged further to support one of said substrates, the center of the supported substrate being substantially coincident over the center of the region;
• a plurality of ledges each adapted to support a substrate placed on the associated surface region, each one of said ledges extending along the associated lower horizontal edge of each one of said surface regions;
• and
• the ledges of respective adjacent walls being displaced such that substrates on adjacent walls when supported on the ledges are not horizontal alignment, wherein the susceptor is a truncated pyramid, the wall widths being tapered such that the width of the upper portions of each wall is narrower than the diameter of the substrate and the lower portion of each wall is slightly larger than the diameter of the substrate, the surface regions in one or more of the upper wall portions having a width less than the substrate whereby the edges of the supported substrate will extend beyond the corner of the intersecting walls.