New Way to Improve RIE Uniformity Using a Metal Pin
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
A new method of improving RIE uniformity is described herein providing for the installation of a metal pin at the center of a grounded electrode in a reactive ion etch (RIE) system. The etch rate of a typical RIE system shows a radial distribution. This effect is known as the "bull's eye" effect, and the wafers near the edge of the cathode etch faster than those near the center. (See Fig. 1.) The effect is primarily caused by the radial electric field distribution between the cathode and the opposing grounded electrode. Shaping the cathode to make the electric field distribution more radially uniform has been proposed. In this disclosure, a new and simpler way of improving the etch uniformity is described. The new method is shown in Fig. 2. A metal pin is placed at the center of the grounded electrode.