Plasma Process for Etching Gold Films
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-01
Three possible methods describing the use of an O2/CF4 or CF4 plasma for gold film etching are provided. Similar results are obtained with O2/SF6 plasmas. Both the provided and prior-art processes produce a volatile etch product. The provided dry plasma gold etching processes are in contrast to the prior-art processes which all use chlorine plasmas or plasmas containing chlorine as etchants for gold. When O2 is present, the gold etching is accompanied by a yellow glow comprised of several sharply headed, red degraded optical bands starting at 563 and 581 nm, shown as the solid trace in the drawing. The absence of the emission when the gold is gone (indicated by the dotted trace in the drawing) allows optical determination of the endpoint of the etching process which proceeds at rates of about 500 A/min.