A vacuum chuck for holding a semiconductor wafer during high pressure, preferably supercritical, processing comprising: a wafer holding region for holding the wafer; a vacuum region for applying vacuum to a surface of the wafer, the vacuum region within the wafer holding region; and a material, preferably sintered material, applied within the vacuum region, the material configurable to provide a uniform surface between the surface of the wafer and the wafer holding region, wherein the material is configured to allow vacuum to flow therethrough. The vacuum region preferably comprises at least one vacuum groove. Alternatively, the vacuum region includes at least two vacuum grooves that are concentrically configured on the wafer holding region. The vacuum groove alternatively comprises a tapered configuration. Alternatively, a coating material is applied between the wafer surface and the substantially smooth holding region surface, whereby the coating provides a seal between the wafer and the holding region.