Wafer-supporting device and method for producing same

A wafer-supporting device for supporting a wafer thereon adapted to be installed in a semiconductor-processing apparatus, comprising, without any structures required for or serving as an electric chuck:

• a base surface comprising an embedded heating element for heating the base surface;
• and
• protrusions protruding from the base surface and having mechanically ground rounded tips for contacting and supporting a wafer thereon, said rounded tips being such that a reverse side of a wafer is supported entirely by the rounded tips by point contact wherein a total area of the rounded tips of the protrusions contacting the reverse side of the wafer is in a range of 10−6% to 10−3% of the area of the reverse side of the wafer, said protrusions being entirely formed of a material which is the same as that of the base surface, which material is aluminum, anodic aluminum oxide, or aluminum alloy, so that there is no difference in thermal expansion between the protrusions and the base surface, and being integrally formed mechanically by mechanical grinding of the base surface and distributed substantially uniformly on an area of the base surface over which a wafer is placed,
• wherein the number (N) and the height (H [μm]) of the protrusions as determined in use satisfy the following inequalities per area as measured for a 300-mm wafer:
• (−0.5N+40)≤H≤53
• 20≤N≤40
• said wafer-supporting device having no clamping mechanism, so as to retain the wafer on the protrusions substantially solely by gravity when in use,
• wherein the protrusions disposed on a diametric line of the base surface are arranged at substantially equal intervals,
• wherein the base surface and the heating element are configured to move up and down;
• and
• wherein the wafer-supporting device is grounded.