Apparatus for and method of backside protection during substrate processing.

摘要

A suitable inert thermal gas such as argon is introduced onto the backside of wafers being processed in a CVD reactor during the deposition of tungsten or other metals and silicides, to avoid deposition of material on the backside of the wafers being processed. Each process station includes a gas dispersion head disposed over a platen. The platen has a circular depression for receiving a wafer, and an annular groove provided in the floor of the depression, near the wall thereof. Heated and pressurized backside gas is introduced into the groove so that the wafer is maintained in a position above the floor of the depression but still within it. In this manner, backside gas vents from beneath the edge of the wafer on the platen and prevents the process gases from contacting the wafer backside. The backside gas is also used for levitating the wafer in a transfer region above the platen, so that the wafer can be transported to or from the platen with a suitable wafer transfer mechanism. One suitable transfer mechanism is a multi-armed spindle, the arms being respective pairs of tines. Another suitable transfer mechanism is a removable structure in which the platens are provided with respective heaters, and the platen-heater assemblies are supported by respective tubes from a central support block. Gas and electrical power are furnished to the platen-heater assemblies from the central support block. <IMAGE>