Process for cementing semiconductor discs onto a carrier plate

A process for cementing semiconductor wafers temporarily onto a carrier plate of a polishing machine so as to permit semiconductor wafers of relatively different thicknesses to be reliably pressed into a cement layer without the occlusion of air bubbles, and such that the upper surfaces of said wafers extend above the cement layer and lie substantially in the same plane, comprising the steps of:

• coating the carrier plate totally with an even layer of cement substance;
• applying the wafers to the cement substance on the carrier plate;
• placing a vacuum-tight sealing dome over the carrier plate, so as to define a sealed hollow space;
• clamping an elastic, chemically-inert diaphragm within said dome 0.2 to 1.5 mm above the free surface of the wafers, said diaphragm dividing the hollow space into two subchambers;
• simultaneously evacuating the entire hollow space defined by said two subchambers to a pressure of 10 to 10.sup.-5 torr;
• subsequently applying air pressure in the subchamber between the diaphragm and the top of the dome by venting said space to an outside air source, so that the wafers are pressed by the diaphragm onto the cement layer;
• thereafter feeding air pressure to the subchamber between the cement layer and the diaphragm, and, removing the dome from the carrier plate;
• allowing said cement layer to set;
• polishing said wafers in a polishing machine;
• and
• removing absolutely wave-free wafers from said polishing machine.