Journal of Vacuum Science & Technology A, Vol.16, No.3, 1489-1496, 1998
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 pressure, total gas flow, and percent of Cl-2 in Ar as variables, and considers some of the environmental, health, and safety issues. The results 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 and 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 address material redeposition, wafer cleaning, and etch chamber cleaning safety issues, major concerns in the RIE of Pt.