Rotating susceptor semiconductor wafer processing cluster tool module

Abstract

A semiconductor wafer processing apparatus or module for a cluster tool is provided with a single wafer rotating susceptor that thins the gas boundary layer to facilitate the transfer of material to or from the wafer, in, for example, CVD for blanket or selective deposition of tungsten or titanium nitride, and degassing and annealing processes. Preferably, a downwardly facing showerhead directs a gas mixture from a cooled mixing chamber onto a rapidly rotating wafer, for example at from 500 to 1500 RPM, thinning a boundary layer for gas flowing radially outwardly from a stagnation point at the wafer center. Smoothly shaped interior reactor surfaces include baffles and plasma cleaning electrodes to minimize turbulence. Inert gases from within the rotating susceptor minimize turbulence by filling gaps in structure, prevent contamination of moving parts, conduct heat between the susceptor and the wafer, and vacuum clamp the wafer to the susceptor. A susceptor lip surrounds the wafer and is removable for cleaning, to accommodate different size wafers, and allows change of lip materials to for different processes, such as, one which will resist deposits during selective CVD, or one which scavenges unspent gases in blanket CVD. The lip smooths gas flow, reduces thermal gradients at the wafer edge.