STUDY OF PLATINUM-ELECTRODE PATTERNING IN A REACTIVE ION ETCHER

This article addresses the problem of Pt electrode etching through the use of a batch load production reactive ion etch (RIE) tool to study etching characteristics and the cleanliness of patterned films with pr essure, total gas flow, and percent of Cl-2 in Ar as variables, and co nsiders some of the environmental, health, and safety issues. The resu lts show that Pt etching is primarily a sputter etch process in which the Cl-2 percentage has little impact on the Pt removal rate, but does significantly affect etch uniformity across the wafer and the surface cleanliness as analyzed with Auger electron spectroscopy. The maximum Pt etch rate achieved was about 5 nm/min with good etch uniformity an d surface cleanliness. X-ray photoelectron spectroscopy of the etch by -products shows the presence of PtCl2 and PtCl4 when the Ar-Cl-2 etch chemistry was used. These results provide useful information to addres s material redeposition, wafer cleaning, and etch chamber cleaning saf ety issues, major concerns in the RIE of Pt. (C) 1998 American Vacuum Society.