DuPont EKC265™ as a Copper Metal Etchant to Assist FIB Edits through Large Copper Power Supply Lines

Abstract

Abstract State-of-the-art semiconductor technologies use multiple copper metallization layers to route power and signals throughout the semiconductor device. These devices have four to six metal layers with the top layers predominately used to route the large power supply lines. To gain access to these lower signal lines, focused ion beam (FIB) must be used to cut large windows through the large power supply lines; this is very difficult. This paper demonstrates how EKC265 can be used as a copper metal etch to remove the copper of the power supply lines. This allows the FIB to cut large windows through the material layers to gain access to the lower metal layers for probing or FIB edits. Results are shown for FIB work using EKC265 and for FIB work without the using EKC265. EKC265 eliminates the need to use the FIB to remove copper giving a much more uniform milling result.