one embodiment each ledge has a width of about 0 125 inch a length of about 0 250 inch and is flush with the face 224 of the susceptor 220 accordingly each ledge 272 has an upward facing support surface 274 having a width of about 0 045 inch for supporting a circumferential side of a semiconductor wafer during epitaxial processing further in one embodiment the ledges 272 are positioned at about 500 from the longitudinal axis 242 of the face 224 and at a radius of about 3 94 inches the rim 260 of the recess 250 is spaced from the wafers during epitaxial processing to allow gas circulation completely around the wafers in the recess a series of holes 290 is positioned in the recess 250 to reduce autodoping tests on a susceptor 220 having the configuration described above yielded epitaxial thickness profiles that varied by less than about one micrometer over a 200 millimeter mm diameter wafer having a three millimeter edge exclusion as with the susceptor 20 of the first embodiment the actual epitaxial thickness increased near the leading and trailing side edges of the wafer when introducing elements of the present invention or the preferred embodiments s thereof the articles u201c a u201d u201c an u201d u201c the u201d and u201c said u201d are intended to mean that there.