An apparatus for depositing a material on a wafer includes a susceptor plate mounted in a deposition chamber. The chamber has a gas inlet and a gas exhaust. Means are provided for heating the susceptor plate. The susceptor plate has a plurality of support posts projecting from its top surface. The support posts are arranged to support a wafer thereon with the back surface of the wafer being spaced from the surface of the susceptor plate. The support posts are of a length so that the wafer is spaced from the susceptor plate a distance sufficient to allow deposition gas to flow and/or diffuse between the wafer and the susceptor plate, but still allow heat transfer from the susceptor plate to the wafer mainly by conduction. The susceptor plate is also provided with means, such as retaining pins or a recess, to prevent lateral movement of a wafer seated on the support posts.